Chapter 6

Models of the User in Design

6.1 A group of universities has decided to collaborate to produce an information system to help potential students find apppropriate courses. The system will be distributed free to schools and careers offices on CD-ROM and will provide information about course contents and requirements, university and local facilities, fees and admissions procedures. Identify the main stakeholders for this system, categorize them and describe them and their activities, currently and with regard to the proposed system.

answer

• Primary - potential students, careers officers
• Secondary - university admissions staff, schools liaison officers
• Tertiary - students' families, local businesses, lecturers on specific courses
• Facilitating - CD designers, university funding authorities

Example description for Careers Officer: (using CUSTOM, reduced form, p 225 of Human-Computer Interaction)

Current system

1. Stakeholder has to provide information to potential students on available courses. Success is measured by student understanding and satisfaction and by the numbers of students matched to appropriate courses.
2. Stakeholder is satisfied by finding a suitable course to meet a student's needs and finds it stressful when information is not available or accessible to meet this need.
3. Stakeholder understands the Universities and Colleges Admissions Service (UCAS) system and knows how to find course details from manuals. Stakeholder has basic IT skills using a PC.
4. Stakeholder enjoys work and feels valued by the organisation. Stakeholder is comfortable with technology.
5. Stakeholder works alone. The only workgroups that are relevant are with class teachers who are consulted intermittently about individual students.
6. Tasks include (1) interviewing students, (2) researching courses and opportunities, (3) writing summary information sheets, (4) liaising with universities and teachers. Some tasks (e.g. 2 & 3) are discretionary and can be done when the stakeholder has time. Others are fixed (1) or event driven (4). Some tasks may be fragmented by interruptions of enquirers 'dropping in'.
7. Stakeholder is bound by confidentiality of individual student details and considers the responsibility of advising students on their futures a significant one.
8. Stakeholder is working in a heated office environment in a school.

Proposed system

1. As before. Stakeholder has to provide information to potential students on available courses Success is measured by student understanding and satisfaction and by the numbers of students matched to appropriate courses.
2. Stakeholder is satisfied by finding a suitable course to meet a student's needs and multimedia system helps to facilitate this. Stakeholder must be assured that the information on the system is accurate and current.
3. Stakeholder understands the UCAS system and knows how to find course details from manuals. Stakeholder has basic IT skills using a PC. Stakeholder must understand how to navigate the multimedia system.
4. Stakeholder is comfortable with technology. However stakeholder may feel less valued as multimedia system allows students to access information directly.
5. As before. Stakeholder works alone. The only workgroups that are relevant are with class teachers who are consulted intermittently about individual students.
6. Tasks include (1) interviewing students, (2) researching courses and opportunities, (3) writing summary information sheets, (4) liaising with universities and teachers. Some tasks (e.g. 2 & 3) are discretionary and can be done when the stakeholder has time. Others are fixed (1) or event driven (4). Some tasks may be fragmented by interruptions of enquirers "dropping in". Task 2. is now facilitated by multimedia system.
7. As before. Stakeholder is bound by confidentiality of individual student details and considers the responsibility of advising students on their futures a significant one.
8. As before. Stakeholder is working in a heated office environment in a school.

6.2 For the scenario proposed above:

• Produce a rich picture showing the problem situation (you can use any format that you find helpful).
• Produce a root definition, using CATWOE, of the system from the point of view of the university.
• What transformations or activities are required to make sure that the root definition is supported?

answer

Rich picture:

Open ended - any notation/drawing is acceptable. It should include all of the actors identified in the answer to 6.1, and the relationships between them, as well as external and internal factors, motivations, and so on. For example, the university is interested in attracting students. It has a number of motivations and issues: raising funds, meeting need for learning provision, demand for resource provision. Students are interested in available locations, quality of learning provision, value for money, closeness to family, and so on. A rich picture can use any notation but should represent the entire system spatially.

Root definition/CATWOE:

A system owned by university management, to be operated by careers staff and students working in careers offices and schools within the context of UCAS regulations and competition from other universities, to sell courses to students, generate income for the university and meet a need for learning provision.

Transformations - examples:

• Need for information about courses -> need for information met
• Need for increased funding -> extra funding generated
• Need for learning provision -> need for learning provision met

6.3 Recall the CCT description of the rule INSERT-SPACE-2 discussed in Section 6.7.2:

	(INSERT-SPACE-2
	IF (AND (TEST-GOAL insert space)
		(TEST-CURSOR %LINE %COL) )
	THEN (  (DO-KEYSTROKE 'I')
		(DO-KEYSTROKE SPACE)
		(DO-KEYSTROKE ESC)
		(DELETE-GOAL insert space) ))

answer

	(INSERT-SPACE-BEGIN-SET-MODE
	IF (AND (TEST-GOAL insert space)
		(TEST-CURSOR %LINE %COL)
		(TEST-NOTE in command mode ))
	THEN (  (ADD-GOAL get into insert mode)))

	(INSERT-SPACE-END-SET-MODE
	IF (AND (TEST-GOAL insert space)
		(TEST-GOAL get into insert mode))
	THEN (  (DO-KEYSTROKE `I')
		(ADD-NOTE in insert mode)
		(DELETE-GOAL get into insert mode)))

	(INSERT-SPACE-DOIT
	IF (AND (TEST-GOAL insert space)
		(TEST-NOTE in insert mode)
		(TEST-CURSOR %LINE %COL))
	THEN (  (DO-KEYSTROKE SPACE)
		(ADD-GOAL get into command mode)))

	(INSERT-SPACE-CLEAN-UP
	IF (AND (TEST-GOAL insert space)
		(TEST-NOTE in insert mode)
		(TEST-GOAL get into command mode))
	THEN (  (DO-KEYSTROKE ESC)
		(DELETE-GOAL get into command mode)
		(DELETE-GOAL insert space)
		(DELETE-NOTE in insert mode)
		(ADD-NOTE in command mode)))

6.4 One of the assumptions underlying the programmable user model approach is that it is possible to provide an algorithm to describe the user's behaviour in interacting with a system. Taking this position to the extreme, choose some common task with a familiar interactive system (e.g. creating a column of numbers in a spreadsheet and calculating their sum, or any other task you can think of) and describe the algorithm needed by the user to accomplish this task. Write the description in pseudocode. Does this exercise suggest any improvements in the system?

This is a pretty open-ended exercise, so no model answer is provided.

Worked exercises

• Create a GOMS description of the task of photocopying a paper from a journal. Discuss the issue of closure in terms of your GOMS description. [page 235]

• Do a keystroke level analysis for opening up an application in a visual desktop interface using a mouse as the pointing device, comparing at least two different methods for performing the task. Repeat the exercise using a trackball. Discuss how the analysis would differ for various positions of the trackball relative to the keyboard and for other pointing devices. [page 250]

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