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University of Birmingham

MSc Computer Science

Designing A Better Combination Microwave

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Contents Page

• Summary of Group Member Contributions

• Abstract

• Introduction

• Definition of Problem Addressed

• Review of Related Work (Analysis of existing combination microwaves) o Overview and Introduction of Current Combination Microwaves o Kenwood Combination Microwave o Panasonic Combination Microwave o Kenwood Solo Microwave o Hotpoint Solo Microwave

• Analysis of User Requirements o Ashley Shaw – Food Stall Owner o Doris Love – Senior Citizen o Barry Parsley – Divorced Father

• First Generation Prototypes o Overview o Prototype 1 o Prototype 2 o Prototype 3 o Conclusion and features to bring forward

• Second Generation Prototype o Description and Overview o Plan and Rationale for Evaluation of The Prototype o User Testing Results o Results and Conclusion

• Summary and Recommendations

• References

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Brief Summary of Group Member Contributions

1. Introduction and Definition of Problem

Addressed Collaboratively

2. Review of Related Work Jay Chauhan

3. Analysis of User Requirements Ed Williams, Cormac O’Sullivan

4. First Generation Prototypes Each completed one prototype and

corresponding analysis

5. Second Generation Prototypes Collaboratively

6. Summary and Recommendations Collaboratively

Abstract

This report addresses the problem of modern day combination microwaves and the usability criticisms associated with them. Combination microwaves have become increasingly difficult to use with unintuitive designs, an overwhelming number of buttons and options and no uniform consistent design across combination microwaves. Since it’s not uncommon for most people in the modern world to use combination microwaves on a daily basis, including senior citizens, restaurants and people with learning difficulties to state a few, combination microwaves need to be made more accessible to everyone. Our team have designed several first-generation prototypes to address the current issues and to offer potential realistic solutions to some of the interface design flaws we discovered. After evaluation, the top features and functionality of these first-generation prototypes were used to augment a second-generation prototype which we believe solves many of the underlying criticisms of existing systems. The second-generation prototype was tested against Nielsen heuristics, given an overall summary and user testing was performed on the prototype to evaluate the suitability of the design. After performing these tests, we believed that the second-generation prototype has the potential to be implemented in the manufacture of consumer combination microwaves and, over time, with some further design improvements, we believe it could become the industry standard for the home appliance industry moving forward.

Introduction

Nearly every modern household owns a microwave. They have become the quickest and most convenient way to prepare hot food, and so it is only natural that recent years have given rise to the combination microwave, a microwave that combines an oven/grill with the expected functionality of a microwave. However, despite their popularity, microwaves and combination microwaves alike lack any form of consistent user interface design. I can vouch from experience, as someone who has recently replaced their microwave, that I still had to read the instructions to figure out how to use my new microwave. Our

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mission is to design a microwave that requires no instructions; a microwave user interface that could set the bar for all future generations of kitchen appliances. As well as being used in a typical household environment, microwaves are used by a broad range of consumers; ranging from the elderly, to professionals, and beyond. In a professional environment, a microwave is required to be efficient and diverse. In contrary, to someone who may consider themselves to be more tech-illiterate, a microwave must be simple and accessible. As such, it was important to us that we cater to as many backgrounds as possible, whilst also fulfilling our mission of creating a universal user interface that could further popularise the combination microwave. With all of this in mind, we created a microwave prototype that seamlessly merges smart technology with classic microwave interface design, so that we may continue familiar appliance design traditions, whilst also introducing a new and intuitive flow of control to the process of using a microwave.

Definition of Problem Addressed

The problems we want to address are two-fold. Firstly, as we’ve already stated, there is no universal standard or consistent design employed by microwave manufacturers. For example, it will be more than likely that when you pick up a smartphone, whether it be an Android phone, an iOS phone, or anything in between, you will easily be able to navigate to most of the core functions, including the phone, text messenger, camera, etc. This is because phones have adapted a near-universal interface that is recognisable to any phone user. By contrast, microwaves have not yet done this. As previously stated, as someone who has recently just purchased a new microwave, I can say that both microwaves were operated very differently. I could operate my old microwave by using only a dial alone. My new microwave does not even have a dial. Whilst admittedly, operating a microwave is no rocket science, and it didn’t take me long to intuitively learn how to use my new microwave by pressing buttons; I still do not know how to use the defrost functionality, which is something I consider to be a core functionality of a microwave. This is a problem. The second problem we’d like to address, concerns the combination microwave specifically. The convenience of having an all-in-one kitchen appliance that can cook, reheat, bake and grill is something that should have entered the mainstream by now. However, the fact that it hasn’t is indicative of a problem larger than the key-concept. A combination microwave has a lot of functionality crammed into one machine, and this can create a big problem when designing an accessible user interface that isn’t too complicated. Having identified these problems, we will now attempt to address them.

Review of Related Work - Analysis of existing combination microwaves and their functionality

Introduction to combination microwaves There is a wide range of combination microwaves offered by multiple brands and suitable for all budgets. The core functionality offered by all of these combination microwaves are very similar to each other:

1. The appliance can perform basic combination microwave functionality that a user requires. 2. For most combination microwaves, users can explicitly state in 10 second intervals the heat

time required, with some other combination microwaves providing users with 1 second increments.

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3. The combination microwave offers ‘shortcut’ functionality for quick access to preset commands within the appliance such as ‘defrost’.

4. The combination microwave has additional cooking functionality that allow users to oven, grill and convection cook their food, meaning they are more of a multi-purpose cooking appliance.

5. The ‘oven’ functionality of the combination microwave allows users to simply oven cook food without using the microwave functionality. For example, users can bake or roast food.

6. The ‘grill’ functionality allows users to grill food. 7. The ‘convection oven’ cooking functionality provides users with a quicker cooking function

using convection fans to evenly circulate air throughout the appliance.

Kenwood Combination Microwave General Approach Priced above £100, this microwave is considered a premium and high-end product. For a product in this price range, user experience and ease of use should be at the forefront of the products design. The user interface is relatively minimalistic with 7 buttons and 1 dial knob providing control for the appliance. The top 4 buttons are for selecting the functionality of the microwave, in this case the options being ‘Microwave,’ ‘Grill Combo,’ ‘Convection’ and ‘Defrost.’ The bottom 3 buttons provided more general purpose functionality such as controls for the clock and timers, stopping and starting the microwave. The bottom turning dial provides the user with control for inputting cooking time, weight of food items being places into the combination microwave as well as other functionality. Strengths

• Compared to other combination microwaves, the use of buttons and worded labels makes some aspects of the appliance relatively intuitive and users won’t have to decipher abstract picture icons to work out the functionality of the buttons.

• The combination microwave has a large display allowing for lots of information to be presented on screen giving users a clear overview of what functionality they are selecting the microwave to perform. Weaknesses

• There are too many buttons leading to an overall static design of the microwave.

• It is unclear just from reading the labels what buttons a user should press first or whether they should turn the dial first.

• In addition, some of the labels on the microwave are counter intuitive and unclear about what functionality they perform. For example, the button ‘Grill Combi’ doesn’t provide a clear definition as to what function this button performs when pressed. Furthermore the turning dial has three functionality labels on it: ‘ Timer,’ ‘Weight’ and ‘Auto Menu’ which again provides very unclear instructions as to what happens when you turn the dial and which function or control a user is changing when they turn the dial. The dial displays three options yet the dial can only be turned in two directions.

[1] KENWOOD K30CSS14 Combination

Microwave

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Panasonic Combination Microwave

General Approach This Panasonic Combination Microwave is at the very top end of consumer combination microwaves with a price of £189.00 at the time of writing. The user interface is of a more complex design with 24 different buttons, 4 different styles for those buttons, an unsymmetrical design and a small display at the top of the appliance. A third of the buttons are used solely for preset functionality of the microwave depending on what food you are cooking. For example, ‘Fish & Chips.’ Half of the buttons are used for time and power settings for the appliance and the rest of the buttons are used for basic operation of the appliance such as starting, stopping and clock settings. Strengths

• Compared to other combination microwaves, this appliance has no strengths or reasons for purchasing it when there are other appliances of equal calibre at a cheaper price range. Weaknesses

• There are far too many buttons leading to a complicated and unintuitive design to the appliance. This overall makes it very difficult to quickly operate the appliance and easily access the desired functionality.

• Many of the buttons on this appliance will rarely and very infrequently get used since their use case is far too specific. For example, ‘Fish & Chips’ is a very specific use case for the microwave and is a redundant function for a vegetarian for example who doesn’t eat fish.

• In addition, the labels used for the buttons are unclear as to the functionality that they offer. For example, ‘Pizza Chicken’ is very ambiguous as to what functionality this button provides. Furthermore, the buttons ‘Up’ and ‘Down’ offer no suggestion as to when you would use these buttons and for what purpose. The ‘CHAOS’ button also seems very out of place and a poor use of the word chaos for a microwave function.

• Even for basic use of wanting to microwave something, it’s unclear how you would go about selecting the microwave function, and when you have selected the microwave function, there are four ‘time’ selection buttons all representing a different increment, meaning that the user would have to mathematically calculate the time in their heads using the increment values in order to select the heating time. This is far too complicated for the simple use case of wanting to microwave something for 45 seconds.

[2] PANASONIC NN-

CT585SBPQ Combination

Microwave

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Kenwood Solo Microwave General Approach This Kenwood microwave offers only basic microwave functionality. It’s only functionality is just being able to microwave, and it has no additional functions such as an oven or grill. It would be considered in the premium price range for solo microwaves, but the overall appearance and sub-standard user interface is again an example of poor design. Strengths

• Similar to previously analysed combination microwaves this microwave lacks any real strong qualities.

• One positive is that it has a number pad for time input which many other models do not feature. Weaknesses

• For a microwave with only one function of microwaving, there are 24 buttons to carry out this one function. This is excessive and ultimately it takes longer for the user to simply heat their food as they first have to decipher what options they need to select.

• Again, there are many redundant and meaningless preset settings such as potato and beverage and these generalisations are so broad that users are unlikely to ever use these features. There are a countless number of ‘beverages’ that could be heated so it’s very unclear as to what beverage this setting is designed for and how hot it will heat the beverage to.

[3] KENWOOD K25MW14 Solo

Microwave - White

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Hotpoint Solo Microwave General Approach This Hotpoint microwave, similar to the Kenwood Solo microwave only has one function and that is to microwave and aims to achieve this goal with a very simple and minimalistic approach to the microwaving user interface. Strengths

• This Hotpoint microwave has a very clean and clear user interface to the problem with few options which doesn’t overwhelm the user with functionality. Weaknesses

• Despite only having very buttons / turn dials on the interface, it is very unclear what these functions actually do since they are not labelled. Hotpoint have opted for the icon approach however their choice of icons is misleading and unintuitive.

• For example, on the on the turning dial there is an icon of what looks like either a lock or a person, it’s difficult to distinguish and furthermore, it’s even more challenging to know that this function actually does!

• In addition, there are more buttons that are unclear as to what their functionality actually is. For example, there is a button that has 3 waves stacked on top of each other, presumably for power but again it’s very unclear as to what will happen if you press these buttons.

Analysis of User Requirements

To validate that the system we design is suitable for the intended user targets we have constructed three different persona’s that reflect expected users and their requirements. For each persona three scenarios have been created that reflect real life expectations of the system to ascertain whether our prototypes meet these demands. This will help us evaluate and critique our prototypes and discover potential problems and improvements. The rationale as to why each type of user was chosen is as follows:

1. High Technology proficiency but low cooking proficiency working person This constitutes a large percentage of microwave owners and thus their needs should be met extensively. These people emphasise efficiency but also simplicity as their cooking knowledge may be lacking. This system should cater for their needs by having a simple design with a large amount of functionality.

2. Fast Food Stall Owner Fast food stall owners use combination microwaves regularly when selling their products at events such as sports matches, music gig and festivals. These people require a large amount of speed so to increase their order outputs. They need efficiency but also consistency to make sure their foods meet the required standards. Our system should accommodate to these users by allowing sufficient speed when inputting their requirements, so the food is produced at a faster rate. 3. Senior Citizen Senior citizens can find modern technology intimidating and as such will not utilise certain products due to this fear. Furthermore, the have a large number of physical and psychological impairments that need to be taken into consideration when designing the system.

[4] HOTPOINT MWH2021XUK Solo

Microwave - Stainless Steel

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Description Ashley Warren is a 51-year old food stall owner that has been running a burrito stall at major music festivals and events nationwide for the last 25 years. This is a family run operation which Ashley now believes has reached its ceiling and thus is now looking to venture out into building a restaurant franchise which unfortunately means she will not have time to run the food stalls herself. Ashley was feeling confident about leaving the running of her business to her Niece and Nephew however at the recent Glastonbury festival they had a surprise inspection by the foods standards agency. During this visit, it was noticed that many the burritos being sold were either not reaching the required temperatures to kill off bacteria, or that they were too hot and thus could cause injury. Due to this the FSA have now put the company on a caution where there will be another inspection in a months’ time. If regulations are not met this could have catastrophic consequences on the company. After a meeting with her employees’ it soon became apparent that this was caused by people using the microwave settings differently and inconsistently due to the confusing interface and lack of training. As Ashley is a perfectionist she has decided that she will not venture out into the franchise business until this problem is solved and thus is looking for an easy to use microwave that will produce consistent results.

Scenarios • It is lunch time at a festival and there is a rush to get food. Orders need to be served quickly and

consistently to produce the high-quality service Ashley requires. • Ashley has been called away for an emergency during a summer fair. She is tempted to close the store

for the rest of the day, but her nephew convinces her otherwise. She would like to be confident in the

fact her high standards will be met without her constant supervision.

• Ashley is hiring on short notice for a new employee for a busy weekend, but she does not have time to

give them extensive training and thus requires them to understand their job very quickly.

Pain Points • Inconsistent microwave food temperatures. • Confusing interfaces that are hard to understand in high pressure situations. • Loud microwaves that make it hard to hear instructions in business environments

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Description Doris is a retired police woman who has become infatuated with baking in her spare time. Although she is well adept in the kitchen she has recently had her house renovated and as such got a whole new set of kitchen appliances. Doris has attempted to bake some cupcakes as a thank you to the builders but soon discovered that she has found the technology in the new appliances hard to understand. Due to this she has now become nervous about using her new kitchen and thus has not done any baking for the last month, much to her dismay. As Doris was careful with her salary she has a comfortable pension so is willing to spend a bit of money on new appliances. However, she wants the assurance that she will be able to easily understand and follow these modern microwaves.

Scenarios • Doris has recently come back into contact with her son and is about to meet her grandchildren for the

first time. Her aim was to teach her grandchildren to bake when they visited but she is worried that this will now not happen due to her confusion in the kitchen, and put further strain on her and her son’s precarious relationship.

• Doris has been asked on short notice to bake some cakes for a local charity fair. She is happy to do so and would like to bake quite a large batch quickly to raise a lot of money for a charity she cares about deeply.

• It is Doris’ turn to host her weekly book club. She always likes to surprise her guests with tea and cake and this week she has decided to experiment with mug-cakes.

Pain Points • Feeling out of depth with modern day technology. • Microwaves that ruin the taste of baked goods. • Modern day appliances that don’t fit in with classic kitchen styles.

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Description Barry is a 39-year old recent divorcee. His ex-wife, Carol, has finally moved out and Barry is living alone for the first time since he left his parents’ house. Consequently, he has never needed to cook for himself, until now. Despite a modest upbringing, Barry’s expectations are disproportionately high. He still expects to eat high-quality food when he returns home from work, in spite of the fact his culinary ability is near non-existent. Much to Barry’s chagrin, he does have a budget, but he also likes to overspend in order to impress his friends and to coincide with his showroom kitchen. Barry lost custody of his two children, but they are allowed to visit on weekends. As such, Barry would appreciate the added functionality of being able to cook for multiple people, but this is not a priority.

Scenarios • Barry has invited some work colleagues around to his condo for supper. He wants to impress with his

food but really can’t be bothered to learn how to cook. He also wants to show off his high-end

kitchen and all of its appliances. • The kids are coming around for Sunday dinner. Barry’s ex-wife is dropping them off and Barry wants to

demonstrate that he is more than capable of feeding his own two children.

• Barry needs to reheat last night’s takeaway for breakfast. He’s running late for work and hasn’t used

the microwave for reheating yet.

Pain Points • Poor tasting microwave food. • Ugly kitchen units with lots of buttons and unintuitive interfaces. • Reading conflated instruction manuals just to perform basic tasks.

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First Generation Prototypes Overview First prototypes are crucial in development as a means of quickly and cheaply evaluating possible ideas for design. From a first prototype we should be able to determine the means and the purpose of a design by focussing on the most important details, without going to the lengths of spending too much time and money building the designs themselves. As part of this phase, we have detailed and analysed three of our own different prototypes. Each prototype has been tailored to a different one of our user profiles, and so each prototype will possess features that will enhance or potentially diminish the user experience for each of our hypothetical users. In either case, we will note the effects of our prototypes’ features. When assessing whether our prototypes have successfully solved the problems and scenarios for our persona’s we will be using a 0-5 scoring system for each scenario and an overall rating average. This scoring system will be broken down as follows: 0 – Functionality is not provided in the system 1 – Very poor performance by system 2 – Bad performance by system 3 – OK performance by system 4 – Good performance by System 5 – Perfect performance by system In order to quickly and conveniently evaluate our three prototypes, we shall be assessing them against Jakob Nielsen’s 10 Usability Heuristics For User Interface Design. Nielsen’s heuristics (1994) are named such because they are considered by Nielsen to be broad rules of thumb, rather than specific to any particular design [5]. In order to assess Nielsen’s heuristics, we will also be using Nielsen’s severity ratings in order to help us prioritise which usability features need the most work or possess the most problems. By using a severity rating, we can tag any usability problems we may find for further assessment, potentially with a view to later remove said usability problem should it be necessary. According to Nielsen, “if the severity ratings indicate that several disastrous usability problems remain in an interface, it will probably be unadvisable to release it. But one might decide to go ahead with the release of a system with several usability problems if they are all judged as being cosmetic in nature” [6].

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Prototype 1 Tool used: Balsamiq Mockups Primary Aim: A balance between simplicity and functionality, overall creating an efficient interface. Rationale The primary motivation and idea behind this prototype was to achieve a balance between simplicity and functionality. This ideology has been adopted as it is beneficial to both everyday home users as well as people working in the food production sector as a simple, easily understandable, design is imperative to efficient usability. A key conclusion from the research conducted was that many mechanical buttons can be confusing and thus inefficient. Therefore, this prototype aims to eradicate these issues by not having any mechanical buttons but instead a large touch screen. Input 1 – Selecting Cooking Method Central to the design philosophy of this prototype was the desire for simple and easily understandable instructions. This main page is effective in doing so as it only allows the user to select one of three inputs. These inputs are whether the user would like to either microwave, grill or oven cook their food. As it is an initial prototype our sketches have been produced in Black and white. However, if this design was to be progressed a colour coding system would be adopted to make it clear what inputs you are selecting. All three buttons are of a large equal size, centrally positioned and the text incorporated inside them is clear. This easily displays to the user’s the options available main screen and make for quick and simple selection, with no waste in time reading superfluous information.

Large touchscreen allows easily changeable information without the excessive reliance on mechanical buttons which can confuse the user.

At this point of user activity, the digital screen incorporated in the middle of the dial is not displaying any information. This is to prevent overloading the user with information.

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“Microwave” selected - Input 2 – Selecting Time If “Microwave” is selected from input 1 the next input that the user selects is the duration they wish for their food to be cooked for. Fitts’s law [7] states that the speed required to click a button is a function of its size and distance from the User. Due to this, we have made the “Start” button large and centrally positioned so that it is easily selectable. The processes:

1. Users are displayed the clear instructions to select the amount of time they wish for their

food to be cooked.

2. They are instructed to turn the mechanical dial to alter the selected cooking time.

3. After they have selected their desired cooking time they press the “Start” button.

4. This takes them to the next input page.

Clear display of the cooking method selected from input 1.

The “Back” button is located at the same place constantly throughout the prototype. This promotes consistency and efficiency for the user. Current time selection

is clear. Showing exact time in minutes and seconds for microwave cooking method.

The “Start” button is large and centrally positioned.

Mechanical dials outer edge lights up. Clearly showing that this needs to be used for the input

Display screen in the centre of the dial shows the current input required. This helps the user to easily understand what they are currently doing.

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“Microwave” selected - Input 3 – Currently Cooking If the “Microwave” cooking method is selected in input 1 and the time has then been selected in input 2 and the user has pressed “Start” this tells the Microwave oven to start cooking the User’s food. While the food is being cooked this prototype clearly displays useful information to the user as well as some options they may choose. The User has the choice of waiting for their food to be cooked or, due to changes in circumstance, they may decide to either pause or cancel this cooking process. If they select the “Pause” button this stops the cooking process where it is at and the user, then has the option to resume or cancel the process. By pressing the “Cancel” button this stops the cooking process and takes the user back to the main input 1 screen.

Clearly displays a timer for the duration of cooking left. (Displayed in minutes and seconds)

Large clear “Pause” and “Cancel” buttons.

The dial display screen is turned off during the cooking process to show no options are required to be selected at this moment in time.

Clear information that the food is currently being cooked.

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“Oven” or “Grill Selected – Input 4 – Selecting the Heating Temperature If either the “Oven” or “Gill” option was selected in input 1 then the next option that must be selected is the desired temperature the User would like their food to be cooked. This is of identical design to the input for time previously mentioned however instead of Time being chosen it is temperature. Once the desired temperature has been selected it carries on as previously mentioned with duration of cooking being selected then display screen whilst food is being cooked. The processes:

1. Users are displayed the clear instructions to select the temperature they wish for their food

to be cooked.

2. They are instructed to turn the mechanical dial to alter the selected cooking temperature.

3. After they have selected their desired cooking temperature they press the “Next” button.

4. This takes them to the next page.

Next stages after Temperature selected for “Oven” and “Grill”

options.

Clear display of the cooking method selected from input 1.

Current temperature selection is clear. Showing exact temperature in degrees Celsius.

The “Back” button is located at the same place constantly throughout the prototype.

The “Next” button is large and centrally positioned.

Mechanical dials outer edge lights up. Clearly showing that this needs to be used for the input.

Display screen in the centre of the dial shows the current input required. This helps the user to easily understand what they are currently doing.

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Evaluation of Prototype 1: Many of the idea’s used in the first prototype have the potential to help with the issues noticed by our users. However, although our aim was for a balance between simplicity and functionality with a lack of additional features this may inhibit our prototypes performance in certain situations. To aide in the evaluation of key elements of our prototypes we have adopted Nielson’s ten usability heuristics, as previously mentioned. Following on from this, we have analysed how effective our prototypes would be in Scenarios envisaged in our user profiles. After a full evaluation has been completed, key recommendations will be identified to help develop and improve future iterations.

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The following table contains features, that after evaluating this early prototype, should be developed into the later generations as they were perceived as useful and effect.

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Prototype 2 Design tool used: Balsamiq Mockups Primary Aim: Favouring functionality at the cost of accessibility. More options, fewer shortcuts. Rationale Prototype 2 was built with the needs of a tech-savvy in mind. Utilising a touch screen designed to occupy the entire front-door of a microwave, this design compromises simplicity for far more functionality than any of our other prototypes, as the home menu offers all of the microwaves functionalities in one go. Whilst this could speed up use, we see a home menu that’s more cluttered than our other microwave prototypes, in favour of functionalities that go beyond the call of duty by having a wide ‘smart’ home screen that’s supported seamlessly by internet functionality. The customisable home screen is heavily inspired by current trends dominating the smart phone and tablet industry, such as Apple’s iPad. Input 1 – Selecting Cooking Method The full-screen touch-screen is the unique selling point of this prototype, and that is where the Home Menu belongs. The Home Menu would function very similarly to the main menu of any smart phone or tablet - a customisable hub for applications relating to cooking and also (somewhat superfluously) entertainment. The key ingredient here was to deliver a sharp, sleek, simple and palatable GUI that was reminiscent of phone and tablet home screen layouts, so that anyone with a smart phone would gain a sense of familiarity from using this combination microwave. All app icons are large and feature small captions describing what they do/are. This helps to avoid clutter but by using the distinctive images pictured on each icon, a user should be able to quickly familiarise themselves with what each app icon does without reading the small caption. Around the edge of the screen are the time, Wi-Fi connectivity status, Bluetooth connectivity status, and a Settings menu. As these are deemed to be non-core features and/or information prompts, we thought it best to include these as smaller icons on the edge of the screen. As stated, the touch screen occupies the entirety of the microwave door. This design choice compromises the freedom most microwaves possess of being able to peer through the plastic window to observe your food cooking, in favour of more screen real-estate. This is a potential design flaw that we may consider amending should we choose to proceed with this design. Possible solutions could involve using the scanner’s camera functionality to produce a live-feed on the screen of what is happening within the microwave.

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“Favourites” selected – Input 2 – Choosing A Favourites Setting As this prototype prioritises functionality over concise simplicity, one of the most important functions for us to implement was the ‘Favourites’ screen. This is for creatures of habit who may regularly eat the same meals, or perhaps industry professionals who depends on quick consistency when using a microwave in a professional catering environment. Favourites is an option that can be selected from the Home screen. The design motivations for this menu are fairly straightforward. The main design principles are carried directly over from the home menu; ‘Favourites’ replaces ‘Home’ as the title of the screen, and each ‘favorited’ meal is clearly placed under a sub-heading that indicates the cooking method. Again, this is to reinforce consistency and familiarity across the operating system for the microwave’s interface. The user is prompted to select whichever pre-set they wish to initiate. Each icon is clearly marked with the name of the meal to be cooked in the microwave. There are no images to occupy the icons as the pre-sets are 100% customised by the user, and the microwave is never to ‘know’ what it is it’s cooking. This generates some slight inconsistency between sub-menus of the microwave, but all-in-all adds clarity to the usability of the microwave.

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Input 3 – Selecting A Cooking Option If either the “Oven” or “Grill” option was selected in Input 1 then the next option that must be selected is the desired temperature that the user would like their food to be cooked. For prototype 2, we decided to make maximal use of the extra screen size and implement a temperature/time selector that dynamically responds to your selection. The processes: 1. Users are prompted with clear instructions to select the temperature they wish for their food to

be cooked at. 2. They input the numbers to represent the temperature they want, and then press ‘Next’. 3. The ‘Select time’ prompt pops up adjacent to where the ‘Select temperature’ prompt was, to

indicate progression along the process of using the grill. 4. The user enters a time and then presses start to begin the grilling process. 5. A loading screen appears (not shown) that will notify the user that the grilling process has begun

and will return the user back to the home screen.

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Evaluation Of Prototype 2 Whilst we may have let our imaginations run slightly wild with prototype 2, we believe there are a lot of innovative ideas taking place here. However, many of them are superfluous and potentially not cost-effective. For example, building a powerful computer into the front-door of a microwave could be very expensive. Additionally, having a system with nearly no flow of progress is problematic, and could be very confusing to some people; that is, having every main function of the microwave clutter the home menu could be overwhelming and unnecessary to many people. With that said, we would really like to advance some iteration of the image recognition functionality in our second-generation prototype, and also the ‘Favourites’ menu could be a very quick convenience for some people.

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User Profiles

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The following table contains features, that after evaluating this early prototype, should be developed into the later generations as they were perceived as useful and effect.

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Prototype 3 Tool used: Balsamiq Mockups Primary aim and target group: Those who need and want a minimalistic, simple design that offers ease of use and doesn’t overload with information. Rationale This prototype has two primary user groups that it focusses on, those who may have special requirements i.e. learning difficulties and those who want a simple, minimalistic design but it also functional without overloading the user with too much information. Combination microwaves often overload users with an excessive number of buttons and options at any given time, and this prototype aims to solve this problem. Therefore, the aim of this prototype is to accommodate the needs of these users with a simple, task driven design. Explanation of the prototype The prototype’s core feature and problem that it aims to solve is, what we call, the task prompting problem. Combination microwaves generally do not tell the user what input should be chosen next or what buttons should be pressed next in order set the settings (heat, time etc.) on the microwave. These combination microwaves overload users with many buttons but no indication of which buttons should be pressed next in the order to achieve the settings the user requires. With this prototype, we have aimed to solve this problem by only ever offering the user a maximum of 4 options for any given setting and a visual text prompt directly instructing the user in which options they need to select next.

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Input 1 – Waking the interface from standby state

To begin using the microwave, the user has to just turn the dial or press one of the buttons on the microwave. The display will switch on and the instructive prompts will guide the user to choosing their desired heat time. All the user must do at this first stage is just turn the dial until their desired microwave function has appeared.

The bottom button at this stage displays no function / text on its screen. This is because the button has no current use for the user as all they are doing at this stage is choosing a function. This adaptive screen makes it very easy for the user to know what options are available to them. The absence of text hints to the user that this button is deactivated at this stage and that they do not need to push it at this current stage.

All the user has to do at this first stage is just turn the dial until their desired microwave function has appeared.

The digital display instructs the user on the available options that they currently have. In this case, the interface is guiding the user to push the display button if they desire the current microwave function that is being displayed. This turn dial, screen and

button combination has been inspired by the popular Nest Home Smart Thermostat that provides functionality but also a neat, minimalistic and intuitive design.

The digital display is mounted on a push button, that can be pressed inwards to select options that are being displayed on the screen.

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Input 2 – Selecting Cooking Method To begin using the microwave, the user has to just turn the dial or press one of the buttons on the microwave. The display will switch on and the instructive prompts will guide the user to choosing their desired heat time.

“Oven” Selected – Input 3 – Selecting Oven Options

All the user has to do at this first stage is just turn the dial until their desired microwave function has appeared.

The integrated turn dial display will alternate through the microwave functions as the user turns the dial.

The digital display instructs the user on the available options that they currently have. In this case, the interface is guiding the user to push the display button if they desire the current microwave function that is being displayed.

The bottom button at this stage displays no function / text on its screen. This is because the button has no current use for the user as all they are doing at this stage is choosing a function. This adaptive screen makes it very easy for the user to know what options are available to them. The absence of text hints to the user that this button is deactivated at this stage and that they do not need to push it at this current stage.

The user will continue to turn the dial until they have found their desired combination microwave function.

Once they have found the function that they want, they follow the instructive prompt on the display to move to the next stage of setting up the microwave.

The user pushes the display push button to select the function, in this case, they are selecting the oven function. The display shows the current options that the user is setting, in this case heat time.

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“Oven” Selected – Input 4 – Selecting Heating Time Once the user has selected the time for the heating operation that they desire and have pushed the digital display button, they are taken to the next set of options for setting the heat options.

“Oven” Selected – Input 5 – Selecting the Heating Temperature

The display shows the current options that the user is setting, in this case heat time.

The digital display also adapts to the with the new information and options available to the user, guiding and advising them on the next steps they should take.

The bottom button has also activated itself, with the digital display showing the function that the button now holds. In this case, the button is displaying the text “back” indicating to the user that if they press the button, they will be directed back one step to the microwave function selection step.

As in the previous

screen, the display

shows the current

options that the user is

setting, in this the

heat of the oven.

In addition, the

display has adapted to

guide the user in

setting the heat by

displaying the text

“Turn to select

temperature.”

Since this is the last step in

setting the combination

microwave heat and time

options, the display has

adapted and now displays a

familiar and intuitive “push

to start” instruction. Once

the user has completed

setting the heat temperature,

they simply press the digital

display button and the

heating / microwaving will

commence following the

user options.

The bottom button is

also active since it is

displaying text. It’s

“back” fiction will take

the user back to the

previous step of

setting the heat time.

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Once the user has selected the time for the heating operation that they desire and have pushed the digital display button, they are taken to the next set of options for setting the heat options.

“Oven” Selected – Input 6 – Heating in Progress Once the microwave has begun the heating operation, once again the displays adapt based on the new options available.

The current microwave function is displayed at the top of the main display, showing users which function is currently being executed.

The heat / cook time remaining is highlighted in large central text.

The display again provides the user with clear options as to which operations are available to them, in this case the “push to pause” instruction will pause the heating until restarted.

The secondary display button at the bottom of the screen has also adapted to show the user what its current function is. By showing the “Cancel” text it tells the user that this button is currently active (has a function) and that if they press the button, the heating operation will be cancelled / ended and the microwave will reset back to the start options in step 2.

As in the previous screen, the display shows the current options that the user is setting, in this the heat of the oven.

In addition, the display has adapted to guide the user in setting the heat by displaying the text “Turn to select temperature.”

Since this is the last step in setting the combination microwave heat and time options, the display has adapted and now displays a familiar and intuitive “push to start” instruction. Once the user has completed setting the heat temperature, they simply press the digital display button and the heating / microwaving will commence following the user options.

The bottom button is also active since it is displaying text. It’s “back” fiction will take the user back to the previous step of setting the heat time.

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Evaluation (Nielsen 10 Heuristics Table)

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33

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Overall Ashley Shaw –

Food Stall Owner Barry Parsley – Divorcee Father

Doris Love – Amateur Baker

Score / 10 3.33 3 0.67

Reason

The design allows burritos to be made consistently to reach the high standard

expected. However, the step by step input means it takes time to cook each

burrito and this equates to a loss of money for the burrito business.

This design looks relatively sleek which appeals to Barry and allows him to make

food efficiently without the need to understand several buttons.

The lack of a pre-heat section or help section meant she was unable to achieve her desired tasks. However, she liked the

simple design even though it incorporated modern technology.

Conclusion and features to bring forward Overall this minimalistic and prompt centric approach clearly guides the user on the next steps they need to take and which buttons / dials to press and when. This solves one of the main problems with existing combination microwaves. The minimalistic and simple design of only having 1 turning dial and 2 buttons works very well in not overloading the user with too much information and options at any given time. However, this simplicity means that some key functionality and standard buttons are missing from these designs. A happy medium design will have to be sought to increase functionality without losing the key essence of the simplicity.

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First Generation Prototypes Conclusion: After analysing and evaluating the three prototypes it became clearly apparent that there were some key features that should be developed into the later generation prototypes. However, there were also some major flaws to the designs either involving the features that were incorporated, or the lack thereof. Overall, after carefully analysing the evaluations, the overall simplistic design of both prototype 1 and prototype 3 were the most optimal and aesthetic. However, although both these designs contained an easily understandable interface, they contained a lack of functionality required for the majority of potential user’s. In contrast, prototype 2 was praised for the high amount of functionality and selection it provided. However, it’s large screen saturated with extraneous information could induce confusion for the user causing these additional functions to become useless. After careful analysis of all first-generation prototypes there are some key concepts to take through and additionally several problems to be addressed. Key concepts to take through:

• Simple interface including both a touch screen and a mechanical dial.

• Easily understandable linear step-by-step progression for cooking method selection.

• Clear instruction of what input the User is currently altering on each page. (E.g. time,

temperature)

• Maintain a balance between simple button instructions and enough information for the User

to know what function each button performs.

• Large clear buttons for the most logical next required or optional function. (E.g. large “Start”

button”)

• Easily able to undo or cancel previous selection without having to redo the whole cooking

method.

• A “favourites” section which allows the User to increase efficiency by selecting pre-selected

options.

• An option that allows the microwave to analyse the food/ it’s packaging and suggest the

options of cooking methods.

Key Problems to address:

• Clear indication of power output required for the microwave setting.

• Indication of what the “Cancel” button does during cooking

• A help section that provides the User with information and guides on how to use the system.

• The interface needs to remain clear and minimalistic to avoid confusing the User.

• The microwave should provide sufficient functionality such as being able to Pre-heat the

oven.

• Clearer methods of distinguishing between the “Microwave”, “Oven” and “Grill” setting.

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Second Generation Prototypes

Evaluation of Tools for Constructing Prototypes For our second generation, we decided to stick with Balsamic Mockups as our prototype designer of choice. Balsamiq is a website that allows you to create graphics in a browser to represent prototypes by assembling a selection of shapes, text and symbols. For added clarity, we did not decide to draw any of our prototypes (including first generation prototypes). Despite the pros of drawing including efficiency and infinite creative freedom, we opted to use a graphics software as that way our prototypes will look cleaner and smarter. It was then a toss-up between Adobe Photoshop and Balsamiq. As a number of our group members are adept at using Photoshop, we decided to give that software a go. Whilst we were able to fully create an image for our prototype, the collaboration process was difficult and slow, as it largely requires one person to work on it at a time, and if there were any mistakes in the prototype, going back to amend these mistakes was a time-consuming process. For these reasons then, we finally settled on Balsamiq as being the perfect compromise between clean design and efficiency. By using Balsamiq, all of our prototypes were designed and agreed upon as a group.

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Description Interface step 1 – Selecting an Option

The home screen follows the design from prototype 1, with clear buttons displaying all the options available to the user, e.g. Microwave, Oven, Grill

Two important features that improved efficiency and ease of use of the design was the favourites section and scanner option. These are now permanently on the home screen as this feature worked will in prototype 2.

When users choose the scanner option, the simply scan their meal using this barcode scanner above the screen interface.

There is also a tactile turn dial as used in prototype1 and 3. The changes functions depending on what options are available to the user. The dial also has a digital display built in to it instructing the user as to which setting they are changing i.e. time / heat.

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“Microwave” Selected - Interface step 2

When the microwave option is selected, the power setting of the microwave is now displayed in the top corner. This addresses an issue with previous designs where this was absent.

The adaptive dial knob lights up to the colour of the function (blue for microwave, this helps with association of function and making it easier for users to know what functions they are using. In addition, the display on the dial knob now shows the text “Time” indicating to the user that if they turn the dial, they will be changing the cook time of the microwave.

Clear big buttons with well stated functions are design features brought forward form prototype 1 which also leave no doubt in the user’s mins as to what their function is. They are also coloured with familiar colours that they can associate to the real world. Green for start (go), red for cancel (stop), much like a traffic light system.

Clear instructions and prompts tell the user what exactly is happening with the system at any given time and what they need to do.

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Interface step 3 – Oven function

When the oven function is selected, the dial knob at the bottom changes colour to green to inform the user that they are in the oven section, and this colour reflects the colour of the oven button on the home screen. In addition, the adaptive display also changes to tell the user which setting they are changing, in this case time and then temperature.

Clear text prompts instruct the user on that they should do. These features were brought forward from prototype 3.

Large text buttons, with clear functions and icons are intuitive and obvious as to when they should be pressed and that function they perform.

Once the user has selected a temperature and pressed the “next” button, they are directed to a screen that offers them the option to preheat the oven. This addresses a problem in prototypes 1 and 3 where there was no preheat function. The preheat selection screen is again very simple and follows the design of the rest of the system, with clear buttons with clear instructions as to what they do. The dial knob at the bottom displays no text, indicating that it is inactive; it has no function in the current screen so turning it will have no effect.

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Selecting Favourites - Interface step 4

This is the process that users will follow when selecting the preheat option, waiting for the oven to preheat and then inserting their food and cooking it. For all of these screens, there are clear, colour coded buttons with large text and documentation instructions informing the user exactly what is going on.

Clear buttons with text and icons. This overcomes issues with existing systems where the choice of icon was poor making it unclear as to the function of the button.

Familiar swipe to scroll touch gestures have been used providing an intuitive method for users to quickly find their favourites / quick heat options.

Turn dial knob lights up in orange to indicate that the user is in the favourites option. No text is displayed indicating that the knob is inactive.

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Scanning Food - Interface step 5 – Using the Scanner to Quickly Input Heating Settings

Plan and rationale for the evaluation of the prototype There were two stages to the evaluation of the second-generation prototype, which combined both a heuristic approach and user testing. Firstly, a usability test was conducted to ascertain any obvious flaws and the overall efficiency of the prototype. Although we considered reusing the previous personas, as seen for the first-generation prototype evaluations, we concluded that setting up new user profiles would be more advantageous as they would be able to find new and unexpected flaws. Although research conducted by Nielson [8] showed that “double specialists” (testers who have both user interface experience and specific domain knowledge) were the most efficient at identifying problems, due to both time and financial constraints we had novice evaluators assess our product. This research also concluded that during the evaluation the ideal balance between cost and effectiveness was to use five evaluators. Each evaluation was performed in solitude to reduce the chance of bias. Furthermore, the evaluators were instructed to perform both a self-guided evaluation and a task-guided evaluation. A self-guided evaluation allows the tester to interact with the system as they please and notice any potential problems that arise. Task-guided evaluations involved the tester to be set a core function of the system to check its performance. We chose this form for the evaluation as it can elucidate a greater number of errors both during distinct tasks and during general walk through of the system.

Once the scan is complete and has retrieved all necessary information about the food to be heated, i.e. a chicken tikka masala ready meal, it displays the different cook options to the user for them to select. All they have to do is push the button for the heat option the would like to use and the operation will begin.

The buttons displayed are outlined in the colour of the heat option that they represent, reflecting the options on the home screen e.g. green for oven and blue for microwave.

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During the evaluation, an observer sat with each evaluator and assessed their performance by both time and success in their task. They also wrote down any issues the evaluators said that they were experiencing. Secondly, an inspection method was conducted which involved repeating the Nielsen Heuristics evaluation that was performed for each of the first-generation prototypes. This type of evaluation was used as it is a quick and easy method of ascertaining any obvious flaws of the system. Furthermore, it can be used with supplementary usability testing methodologies such as our user testing. However, we need to be aware that although it can find some minor issues there may be situations where major flaws are not discovered.

User Testing Results User 1: John User Background: Cooking proficient evaluator Task: Set the oven setting to preheat at 180 °C Observations:

• Found the system easy to understand and follow.

• On the preheat setup page they were confused with exactly what would occur next when pressing

the “Yes” button as there was no information explaining what the next step would be.

• One point of confusion noted was the lack of arrows on the dial indicating which way

increased/decreased the time/temperature input.

• During the self-guided walkthrough was surprised by the lack of a de-frost setting as they deemed

this a required feature of a combination microwave.

User 2: Sarah User Background: Technology proficient evaluator Task: Read simple instructions and successfully heat up a microwave a microwave meal Observation:

• Felt like the simple, informative step-by-step process made setting up cooking options very simple.

• Also felt like the button placement was correct for most inputs and was clear what the next step

should be.

• Liked that the screen on the mechanical dial displayed what input they were currently selecting.

• Felt like the back button for each input page was too small so took a bit too long to find when an

error was made.

User 3: Sandra User Background: balance of technology and cooking proficiency Task: Utilise the Grill setting in under 2 minutes with instructions for time and temperature Observation:

• Found the navigation through the system straight forward however felt it was quite repetitive and

time consuming in some aspects.

• Found the repetition of colours used for the grill/oven and start/cancel inputs confusing when

selecting the grill setting.

• They thought that by pressing the start button this was initiating the grill setting and pushing the

cancel button was stopping a different oven function due to the matching colours.

• This caused them to breach the 2-minute target and inhibited the usage.

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User 4: Kieran User Background: Owns fast food outlets where efficiency is paramount Task: Input a new favourites option Observation:

• Found setting up a cooking method extremely efficient.

• Liked the scrolling panel design and commented on the potential effectiveness of the favourites

methods idea in the food outlet market to improve efficiency.

• However, did mention the confusion of the mechanical dial light being turned on during the

favourites selection, even though this only indicates that a selection is being made (e.g. time and

temperature) in the rest of the system.

User 5: Mary User Background: Elderly Person Task: Set up a WIFI connection and use the bar-code scanner to heat a microwave meal Observation:

• Found setting up a WIFI connection extremely confusing as there was no information surrounding

how to do it.

• When looking for a help section to explain how to solve this issue was unable to do so.

• In general, liked the simplistic design, and the use of colour coding, of the system as she was not

overloaded with information.

• However, found that some of the font size, such as the information under the “Cancel” button, was

too small.

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The table below evaluates observations made during the User testing and the evaluation made by

the designers themselves conduct a final heuristic analysis.

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Results and Conclusion Overall, the use of the Usability Testing as our evaluation method was effective of not only discovering the right features of our prototype, but also some issues and flaws that were previously unthought-of by the designers. This is because, although the developers try to discover all weaknesses and issues before the developments of the prototype there will always be an unknown bias. Using the Nielson Heuristics table to summarise key points of our prototype was also effective as it showed use some obvious flaws which we can now begin to amend. If there was a greater amount of time and financial opportunities available for future evaluations, I believe performing further user testing would be effective but instead of novices, the utilisation of “double specialists” would be optimal in finding further issues. From assessing the observations made by the evaluators our second-generation prototype has made some significant improvements on the first-generation prototypes. Overall, there was a large satisfaction with the simple, aesthetic design of the system and the step-by-step process utilised when setting up a cooking method. Also, they found the use of both a touch screen and mechanical dial effective and efficient at setting required options. However, it became apparent that there were still several issues that need to be solved. These issues can be separated into both minor and major problems with the system. The minor issues noticed included:

• A lack of button size for some inputs and information such as the “Back” button.

• The small font size for supplementary information such as the instructions such as “Turn the dial”.

• The confusion caused by the multi-use of some colours for the colour-coding system such that red

indicates both the “cancel” button and “oven” setting, while green corresponds to the “Start” and

“Grill” inputs.

• The lack of arrows on the mechanical dial indicating which way increased or decreased the input

such as time or temperature.

As these are minor issues they can be easily solved for the next generation and will improve both the efficiency and usability of the system thus making it more effective at its task. Major problems discovered during the usability testing included:

• A lack of a Help section containing documentation explaining what different functions are and how

to use/ change them. This is a major issue and without it some users are unable to utilise key

functions of the combination microwave and receive no help in understanding how their issues can

be solved.

• This usability testing also discovered an unknown user requirement. The lack of a “de-frost” setting

is a massive flaw as it is regarded a key feature required for the microwave setting of a combination

microwave.

Implementing the solutions to the major issues identified could improve the user experience significantly. Overall, although the 2nd generation prototype was an improvement on its predecessors there is still some issues that need to be eradicated when going onto the next stage of development. Simple recommendations that should be implemented is the alteration of the colour code system to reduce confusion, the ability to increase font size (in the settings section) to increase usability for users with poor eyesight, designing arrows clearly indicating when you are causing an increase/decrease when

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using a dial and lastly changing some button sizes (e.g. the back button) to make it clearer what it implements. Further large-scale changes that should be implemented in the next prototype should be including a Help section in the settings menu clearly explaining the different functions of the system and how to use them. Also, a further de-frost function should be included in the microwave section of the system as this is a core function required for combination microwaves. With these solutions implemented, alongside the strong simplistic, step-by-step design of the current prototype, the next generation will be more effective at utilising the tasks required by the user.

Summary and recommendations This report analysed and evaluated existing combination and solo microwave systems in order to expose and identify the current problems and criticisms of these existing systems. We found that despite the majority of people in the modern world owning and using a combination microwave, using the appliance to its full potential i.e. it’s advanced functionality and even its basic functionality was challenging for many people, with complicated designs, too many buttons and unintuitive interfaces making it challenging for people to carry out even simple tasks. Overall, we designed a combination microwave user interface aimed at allowing anyone to use combination microwaves efficiently and with ease. To achieve this goal, we focussed and implemented 5 main design aspects that we believe we could significantly improve user experience:

1. Designing an interface that could be used as a global standard for use in all future manufacturing of combination microwaves.

2. Simplifying the user interface such that users aren’t overwhelmed with an excessive number of poorly labelled buttons.

3. Using modern interface design techniques to make using the appliance feel familiar and intuitive meaning users don’t have to unnecessarily think hard to work out what buttons / options they need to select.

4. For users that use repetitive heat and cook options, providing them with a method to quickly set the microwave so that they don’t have to waste times inputting repetitive functions.

5. Implementing instructive prompts into the microwave system so that users are guided through setting the microwave and so that they know exactly which buttons and options they need to select next.

By adhering to the above design features, we were able to satisfy the requirements from our personas and scenarios to great effect, this prevented us from committing the same design flaws of the evaluated existing combination microwaves. There were few advantages of the existing systems for us to bring forward and incorporate in to our designs, so our designs were built from the ground up based solely on personas, user scenarios and our own personal criteria. Our first-generation prototypes focussed on designing interfaces that attempt to strike a balance between functionality and ease of use. We found that this was more challenging than anticipated since when incorporating more functionality in to the system e.g. microwave, grill, oven and preheating, the more complex the system and interface became. Furthermore, when we approached the design from a minimalistic viewpoint, functionality was lacking from our designs in order to maintain this simplicity. However, through understanding the importance of the personas

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and scenarios we generated three first-generation prototypes that we believed achieved a happy medium between functionality and simplicity. When considering the wide range of users that would be potentially using our system, we appreciated the key features that were essential to take in to our second-generation design. Efficiency, ease of use, functionality and minimalism were at the forefront of our design and our analysis and evaluation of first generation prototypes indicated at many positive features to bring forward in to our next iteration. Overall, there were many positives conclusions and realisations that we discovered from our evaluation and design process. With some minor improvements and adjustments, there is no reason why our systems couldn’t be implemented in future designs of combination microwaves. With the direction that technology is heading it’s only a matter of time before digital touch screens are being implemented in all combination microwaves and we believe the design aspects we researched and explored provide, at the very least, a good foundation for the future of how humans interact with the computers in the combination microwaves.

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References [1] Currys Website, https://www.currys.co.uk/gbuk/household-appliances/cooking/microwaves/kenwood-k30css14-combination-microwave-stainless-steel-21780571-pdt.html, 30/10/2017 [2] Currys Website https://www.currys.co.uk/gbuk/household-appliances/cooking/microwaves/panasonic-nn-ct585sbpq-combination-microwave-stainless-steel-10127538-pdt.html, 30/10/2017 [3] Currys Website, https://www.currys.co.uk/gbuk/household-appliances/cooking/microwaves/kenwood-k25mw14-solo-microwave-white-21789551-pdt.html, 30/10/2017 [4] Currys Website, https://www.currys.co.uk/gbuk/household-appliances/cooking/microwaves/hotpoint-mwh2021xuk-solo-microwave-stainless-steel-10100552-pdt.html, 30/10/2017 [5] Nielsen’s Website, regarding usability heuristics, https://www.nngroup.com/articles/ten-usability-heuristics/, 27/10/2017 [6] Nielsen’s Website, regarding severity ratings, https://www.nngroup.com/articles/how-to-rate-the-severity-of-usability-problems/, 27/10/2017 [7] MacKenzie I. Fitts' Law as a Research and Design Tool in Human-Computer Interaction. Human–Computer Interaction. 1992;7(1):91-139. [8] Nielsen, J. Finding usability problems through heuristic evaluation. In Proceedings of the SIGCHI conference on Human factors in computing systems (pp. 373-380). ACM. 1992, June