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Transcript of Usability Testing
- 1. User Centered Design (UCD) 1 UCD is a design philosophy where the end-users needs, wants and limitations are a focus at all stages within the design process and development lifecycle. Products developed using the UCD methodology are optimized for end-users and emphasis is placed on how the end-users need or want to use a product instead of forcing the end user to change his behavior to use the product.
2. What is Usability Testing? Usability testing evaluates how well people can actually use something (such as a website, web application, document, device, food, or any product) for its intended purpose. During usability testing, developers are not expected to explain their product to the user or argue about its merits. The aim is for them to observe a real user use their product in as realistic a situation as possible, so as to discover errors and possible areas of improvement. Usability Test in a Lab 2 3. Definition of Usability Testing Usability is a quality attribute that assesses how easy user interfaces are to use. The word "usability" also refers to methods for improving ease-of-use during the design process. Usability is defined by 5 quality components: Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design? Efficiency: Once users have learned the design, how quickly can they perform tasks? Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency? Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors? Satisfaction: How pleasant is it to use the design? This definition is by Jakob Nielsen one of the most respected experts in the field of UT. 3 4. Types of Usability Testing Lab based testing. This type of UT involves recruiting participants and observing their behavior as they do a series of tasks designed to test usability testing. Often involves video-taping the user. Web based testing. This type of UT involves asking users of a product to respond to a series of questions about their user experience. Cognitive Walkthrough. This type of UT involves an evaluator who does a set of specific tasks rather than the actual user. The idea is for the evaluator to assume the role of user. In this project, you are being asked to do a cognitive walkthrough. 4 5. What is a Cognitive Walkthrough? In this assignment, you are being asked to do a type of usability testing method known as a cognitive walkthrough. In a cognitive walkthrough, an evaluator does a set of specific tasks rather than the actual user. ___________________________ NOTE: some developers restrict the definition of usability testing to tests of a product by actual users and categorize a cognitive walkthrough as a type of usability inspection, but we dont need to get this far into the weeds ). 5 6. Designing Your Test 6 7. Step 1: Decide What to Test Choose two (or more) communication products. Here are some examples: Word vs. Google Docs (word processing) Autocad vs. SolidWorks (3D modeling) Weebly vs. Wix (web site creators) Blogger vs. Tumblr (blog site creators) Infragram vs. Picktochart (infographic creators) Gimp vs. AdobePhotoshop (image editing) Many more possibilities exist. What you choose should be comparable. PowerPoint vs. Blogger (not comparable). What you choose should not cost you anything. Do not sign up for a trial version of any tool. Often, companies make it very difficult for you to unsubscribe. For example, Gimp is free, Adobe Photoshop is expensive. If you do not have access to the latter, try another free tool that is comparable to Gimp. NOTE: if you want to test something other than communication product, just let me know, so I can approve your choice. 7 8. Step 2: Identify typical users of the product. Compose a description of these users. The description will be part of the white paper you write of your findings from the test. You will want to identify the level of knowledge the user has. For example, engineers use AutoCad and SolidWorks, so a description of what knowledge these users would have relative to the products would be different from a user who is not an engineer or studying enginering. Sometimes identifying typical users can be difficult. If the product will be used by a wide-range of users with varying levels of technical expertise, think about what level of expertise you envision that your user has when designing the tasks. Are they a novice user with little of no experience using a product? Would they likely be using one product but not the other? Try to focus on a specific group of users if possible. Become the user. Remember, that this is not about your personal experience with the product, but with the user you identify (obviously, you cannot test something as a user with a higher-level of experience than yourself). 8 9. Step 3: Decide the Tasks You will need approximately ten specific tasks. This is a guideline only because the number of tasks depends upon the complexity and what you are testing. You need enough complex tasks to evaluate usability. Avoid tasks that are too basic. Tasks that are simplistic, such as testing how Word saves a document compared to Open Office, do not really test usability since how you save a document file is easy and much the same in any word processing software. Apply your user description. To help you decide what specific tasks to test, you need to analyze what the user you have defined would be doing with the product and how. Example: how does a user login to the product? If a user needs to set up an account, then that could be the first task. 9 10. Step 3: continued Consider the following when designing tasks. Affordance: what does the product allow you to do. Can you do the task? Constraint: what does the product prevent you from doing. Is there a task you cannot do or a task you can do, but not to your satisfaction? Ease-of-Use: as you complete each task, consider how easy or difficult it was to do. Aesthetics: Does the products style and appearance enhance your user experience? Visibility / Functionality: are the possible actions you can perform easily found and used? Feedback: when you do an action, does the product give you feedback where needed (i.e. you understand if the action was completed or what to do next etc.)? Mapping: do you know where you are as you perform each task or are you getting lost? Time / False Starts: how long does it take you to perform an action and is that amount of time reasonable? How many times did you attempt an action that did not work? 10 11. Step 4: Decide the Equipment and Location Laptop or Desktop? PC or Mac? Location of Testing Your residence? Computer lap on campus? Be consistent. For example, dont do the test on a Mac for one product and a PC for another. You want to do the test using technology you are familiar with so it does not interfere with the results. 11 12. Step 5: Decide the Criteria and Rating Scale You will need specific criteria connected to a Likert Scale that allows you to evaluate and score usability. You will want to consider both the tasks and what you want to evaluate when writing criteria statements to evaluate these. Likert Scales are composed of a series of statements that a user responds to in order to evaluate usability based on a number of options available. The number of options is generally five. Here is an example: I was able to do the task with little or minimal consultation with the products Help section. 12 Strongly Agree Somewhat Agree Agree Somewhat Disagree Strongly Disagree 5 4 3 2 15 13. Step 5: continued. Likert Scales Because Likert Scales associate qualitative data with quantitative data, the way they are designed is a matter of some debate. We dont want to get too far in the weeds about problems associated with Likert Scales such as how to improve the Likert Items in order to ensure more valid responses. You are simply practicing how to measure qualitative data (the description of what happens when you do the test) with quantitative data (a numerical ranking measurement based on criteria). So, now you are ready to create a data collection form. You will use the form to make notes and score usability. Your notes and scores will be the findings you report in your white paper for this project. 13 14. Step 6: Create a Data Collection Form. You will use the form to take notes and score the products for usability. These findings will be reported in your white paper. Task Product 1 Score Product 2 Score 1. Create an Account and Login for the first time. Usability description (what happened when you did the test) 5 Usability description 2 I was satisfied with the time it took, to do this task. I was satisfied with the time it took, to do this task. Repeat for all tasks. 14 5 2 This is just one example of how to design your data collection form. There are other ways to do this. Make choices based on what works for your products and task choices. 15. Step 6: continued. Data Collection Form Remember, you will be doing a set of tasks to test usability and describing/rating what happened when you did the test. Identifying the features that a product offers is not the same as testing that product for usability. When you do the task, you may find a feature that is special to that product and/or particularly useful (or not). In that case, connect the feature to the concept of usability as you take notes on what happened as you did the task. 15 16. Step 7: Do the test Be certain you are in an environment where you can concentrate without interruptions. You can do the test in more than one sitting. For example, try testing one product, and then do the other at another sitting. Use the data collection form to take notes. This will be your raw data that you use for the white paper write-up. 16 17. Step 8: Write Up the Findings You will write up your test findings in a white paper. What white papers are and how to write one using your data is covered in another lecture. 17