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BASIC INFORMATION

CSC 446 HUMAN COMPUTER INTERACTION

BY

Mensah Peter Jnr

Department of Computer Science,

2014

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THE DESIGN PROCESS

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Learning Objectives

Upon successful completion of this topic, students should be able to:

•Define Design

•Describe the process involved in design

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Definition

Design can be defined as achieving goals within constraints.

Goals• What is the purpose of the design we are intending to

produce?• Who is it for?• Why do they want it?

•Constraints• What materials must we use? • What standards must we adopt? • How much can it cost? How much time do we have to

develop it?

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Golden Rule of Design

The golden Rule of design is to understand your material. The material been used here refers to the things needed to accomplish the design process.

In interactive Design the material refers to

– Human

– Computers

To consider the golden rule of design it means we must understand human and Computers.

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Design Process

In order to design something we must undergo certain processes. Here we’ll take a simplified view of four main phases plus an iteration loop, focused on the design of interaction

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Design Process cont

In consideration of the design Process diagram we can therefore consider the phases as follows:

Requirements

Analysis

Design

Evaluation (Prototype evaluation)

Implementation

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Requirements

Requirements simply means looking for what you wanted.

The first stage of the design process is establishing what exactly is needed. Or identifying what exactly you want the system to accomplish.

There are a number of techniques used for this in HCI:

– interviewing people,– videotaping them,– looking at the documents and objects that they work

with,

– observing them directly.

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Requirements

In order to get good design you must first understand the requirements. We will consider several approaches that will help us get the requirements: socio-technical modeling, soft systems methodology, participatory design, ethnographic methods and contextual inquiry.

Before we look in more detail at these approaches we need to clarify what we mean when we talk about ‘stakeholders’.”

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Stakeholders

• Understanding stakeholders is key to many of the approaches to requirements capture, since in an organizational setting it is not simply the end-user who is affected by the introduction of new technology.

• Stakeholder, therefore, can be defined as anyone who is affected by the success or failure of a system.

• Stakeholders can be categorized into: – Primary stakeholders are people who actually use the system

– the end-users

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Stakeholders

•Stakeholders can be categorized into: – Primary stakeholders are people who actually use the system

– the end-users – Secondary stakeholders are people who do not directly use

the system, but receive output from it or provide input to it (for example, someone who receives a report produced by the system).

– Tertiary stakeholders are people who do not fall into either of the first two categories but who are directly affected by the success or failure of the system (for example, a director whose profits increase or decrease depending on the success of the system).

– Facilitating stakeholders are people who are involved with the design, development and maintenance of the system.

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Socio Technical Models

Socio-technical models for interactive systems are therefore concerned with technical, social, organizational and human aspects of design. They recognize the fact that technology is not developed in isolation but as part of a wider organizational environment. It is important to consider social and technical issues side by side so that human issues are not overruled by technical considerations.

In this we will consider two socio technical models that can be used to capture the user requirements.

– CUSTOM models

– OSTA model

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CUSTOM model

CUSTOM model is a socio-technical methodology designed to be practical to use in small organizations.

It is based on the User Skills and Task Match (USTM) approach, developed to allow design teams to understand and fully document user requirements.

It is a forms-based methodology, providing a set of questions to apply at each of its stages. There are six key stages to carry out in a CUSTOM model :

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CUSTOM model

1. Describe the organizational context, including its primary goals, physical characteristics, political and economic background.

2. Identify and describe stakeholders. All stakeholders are named, categorized (as primary, secondary, tertiary or facilitating) and described with regard to personal issues, their role in the organization and their job.

3. Identify and describe work-groups. A work-group is any group of people who work together on a task, whether formally constituted or not.

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CUSTOM model

4. Identify and describe task–object pairs. These are the tasks that must be performed, coupled with the objects that are used to perform them.

5. Identify stakeholder needs. Stages 2–4 are described in terms of both the current system and the proposed system. Stakeholder needs are identified by considering the differences between the two.

6. Consolidate and check stakeholder requirements. Here the stakeholder needs list is checked against the criteria determined at earlier stages.

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OSTA model

OSTA is an alternative socio-technical approach, which attempts to describe what happens when a technical system is introduced into an organizational work environment. Like CUSTOM, OSTA specifies both social and technical aspects of the system. However, whereas in CUSTOM these aspects are framed in terms of stakeholder perspectives, in OSTA they are captured through a focus on tasks.

OSTA has eight main stages:•The primary task which the technology must support is identified in terms of users’ goals.

•Task inputs to the system are identified.

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OSTA model

3. The external environment into which the system will be introduced is described, including physical, economic and political aspects.

4. The transformation processes within the system are described in terms of actions performed on or with objects.

5. The social system is analyzed, considering existing work-groups and relationships within and external to the organization.

6. The technical system is described in terms of its configuration and integration with other systems.

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OSTA model

7. Performance satisfaction criteria are established, indicating the social and technical requirements of the system.

8. The new technical system is specified.

OSTA uses notations familiar to designers, such as data flow diagrams and textual descriptions.

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Soft System Methodology

The socio-technical models we have looked at focus on identifying requirements from both human and technical perspectives, but they assume a technological solution is being proposed. Soft systems methodology (SSM) arises from the same tradition but takes a view of the organization as a system of which technology and people are components. There is no assumption of a particular solution: the emphasis is rather on understanding the situation fully.

SSM was developed by Checkland to help designers reach an understanding of the context of technological developments and the influences and concerns that exist within the system under consideration.

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Soft System Methodology

The SSM has Seven stages as shown in the diagram:

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THE BARBER

A man went to a barbershop to have his hair cut and his beard trimmed. As the barber began to work, they

began to have a good conversation. They talked about so many things and various subjects.

When they eventually touched on the subject of God, the barber said: "I don't believe that God exists."

"Why do you say that?" asked the customer. "Well, you just have to go out in the street to realize that God

doesn't exist.

Tell me, if God exists, would there be so many sick people? Would there be abandoned children?

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If God existed, there would be neither suffering nor pain.

I can't imagine a loving God who would allow all of these things."

The customer thought for a moment, but didn't respond because he didn't want to start an

argument.

The barber finished his job and the customer left the shop.

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Just after he left the barbershop, he saw a man in the street with long, stringy, dirty hair and an

untrimmed beard.

He looked dirty and unkempt.

The customer turned back and entered the barber shop again and he said to the barber:

"You know what? Barbers do not exist."

"How can you say that?" asked the surprised barber.

"I am here, and I am a barber. And I just worked on you!"

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"No!" the customer exclaimed.

"Barbers don't exist because if they did, there would be no people with dirty long hair and untrimmed

beards, like that man outside."

"Ah, but barbers DO exist! That's what happens when people do not come to me."

"Exactly!" affirmed the customer.

"That's the point! God, too, DOES exist!

That's what happens when people do not go to Him and don't look to Him for help.

That's why there's so much pain and suffering in the world."

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THE ENDTHANK

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