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EXAM A WITH SOLUTIONS

Part I (worth 40%)Attempt four questions from the six in this part. Each question is worth 10 marks.

Question 1(a) Explain the following terms:

(i) Affordance(ii) Visibility (iii) Feedback [4]

(b) Give an example of good affordance from a mobile telephone. [2](c) Give an example of good visibility from a mobile telephone. [2](d) What is the relationship between feedback and affordance? [2]

Sample Solution 1(The following definitions are taken from the Chapter 5 and the glossary)

Affordance: an aspect of an object that makes it obvious how the object is to be used. [1]

Visibility: the properties of an object that make it obvious what it is used for. [1] Feedback: information sent back to the user to confirm what action has been done

and / or what result has been accomplished. [2] Example of good affordance: the send button is raised and button shaped

suggesting that it should be pressed. It is also a different color, making it stand out. [2]

Example of good visibility: the number is printed on each button, suggesting that when the button is pressed, that number will be displayed on the screen and will be dialled (immediately or after the whole number has been entered, depending upon the phone). [2]

The relationship between feedback and affordance – affordance is similar to feedback as it tells the user how a control is operated. [2]

[Total of 10 marks]

1


Question 2(a) What is a mental model? [2]

Describe 2 characteristics of mental models that might influence interaction, giving examples of how these might influence a user interacting with a wordprocessor. [4]

(b) Define in detail what is meant by an interface metaphor, giving an example. [3](i) How can an interface metaphor influence the learning of a new computer system?

[1]

Sample Solution 2(i) See Chapter 4

“A mental model is a mental representation that people use to organise their experience about themselves, others, the environment and the things with which they interact.” (Course glossary) [2]

Characteristics: They are usually incomplete – e.g. the user may not know how to use style sheets

in this WP. They contain errors e.g. The user may belive the save icon allows you to specify the

file name (this is not true in MS Word). Can be run e.g. the user may anticipate how he would alter the margins stepping

through this action in his mind before actually doing it etc.[4]

(ii) (See Chapter 10) An interface metaphor is the metaphorical use of words on the screen, static images and icons, and interactive graphics. These elements are used metaphorically when the designer deliberately draws upon the users’ existing knowledge. (Glossary) [2]An example may be the calculator that comes with Windows. [1]

(iii) It draws in the user’s knowledge of a familiar domain and allows him or her to form an accurate mental model more quickly. [1]

[Total of 10 marks]

2


Question 3(a) Explain the difference between discrete and continuous input devices. [2](b) Give two strengths and two limitations for each of the following input technologies.

(i) Joystick [2](ii) Touch screen [2](iii) Trackball [2]

(c) For the joystick and the touch screen, identify if it is discrete, continuous or both. Briefly explain your answers. [2]

Sample Solution 3(Course Glossary) A discrete input device is designed to handle digital data; a continuous input device is designed to handle analogue data. [2]

See Chapter 12

Joystick. Strengths; operate in two dimensions, good at indicating direction and speed, rather than location. Limitations; not that durable, imprecise.

[1 mark for 2 strengths, 1 mark for 2 limitations. Total of 2 marks]

Touchscreens. Strengths; little learning required, good for casual users, fast for pointing, little workspace required, durable, easy to maintain. Limitations; relatively costly, can cause arm fatigue, hands may obscure screen.


Trackball. Strengths; can be good for disabled users with poor motor control. Good where space is limited. Limitations; tend to be quite slow to use. Users have a less positive attitude to these.


Joystick are continuous devices as they typically smoothly move the cursor across the screen. In contrast touch screens can be both continuous (dragging an icon around the screen) and discrete (tapping on an icon to activate it). [2 marks]

[Total of 10 marks]

3


Question 4(a) Define the term: interaction style. [2](b) Choose two distinct types of interaction style. For each:

(i) Describe the interaction style;(ii) Explain how it supports (or does not support) the Planning an action sequence

stage in the human-action cycle;(iii) Explain how it supports (or does not support) the Perceiving what happened

stage in the human-action cycle; (iv) Give a brief example illustrating when the interaction style would be used and why

its use would be appropriate. [8]

Sample Solution 4“An interaction style is a collection of user interface controls and their associated behaviour from which a designer can choose. The interaction style provides both the look (appearance) and feel (behaviour) of the user interfaces, indicating the way a user will communicate with the system”.

Chapter 11 [2]

Command line: User enters a command from a formal command language; this tells the computer

what to do. [1] Planning an action sequence – doesn’t help much because the user is required to

recall the different (often esoteric) commands. [1] Perceiving what happened – again it doesn’t help much because often very limited

feedback is provided. [1] Use: some operating systems. This is appropriate because most operating systems

are used by experts who already know the commands and who have a good mental model of what is going on inside the machine. [1]

Direct manipulation: User manipulates screen objects to control the computer (operates in a manner

analogous to the real world). [1] Planning an action sequence – helpful because the possible actions are visible [1] Perceiving what happened – again helpful because the effect of the action is

immediately visible [1] Used in GUI interfaces. This is appropriate because many GUIs are used by

novices who need support through the interaction process – the emphasis on recognition rather than recall really helps. [1]

(Similarly for menus, form-fill or anthropomorphic interaction styles)

[Total of 10 marks]

4


Question 5(a) What is the primary purpose of evaluation in user interface development? [1](b) Describe what is meant by heuristic evaluation and highlight four ways in which it

differs from user observation. [3](c) Identify two benefits and two limitations of heuristic evaluation. [4](d) Would you use heuristic evaluation if you were developing an interface for the control

panel of a new space craft? If so, explain how it would fit within your evaluation plans. If not, justify your decision. [2]

Sample Solution 5(a) To assess the UI against its usability requirements.Give one half mark for assessing and one half mark for usability requirements.

[Total 1 mark]

(b) Heuristic evaluation is a form of inspection where an inspector evaluates the UI against a set of guidelines or standards. It differs from user observation because 1. inspectors are used instead of users, 2. the session does not need to be carried out in the realistic setting, 3. recording of the session is not necessary because the inspectors write defect

reports, 4. heuristic evaluation can be quicker and cheaper than running user observations.

[3]See Chapter 26 for a description of heuristic evaluation. Give 1 mark for description of heuristic evaluation and one half mark for each of the four differences.

[Total 3 marks]

(c) Chapter 26 lists 3 benefits and 4 limitations.Benefits: Inspections can be less expensive than user-observation;During an inspection, inspectors more often than not suggest solutions to the usability defects that they identify;It can be annoying to discover a large number of obvious errors during a user-observation session. Inspecting the UI first can help reveal these defects.Limitations:As usability inspectors often do not involve real or representative users, it is easy to make mistakes in the prediction of what actual users will do with the UI;Inspectors often differ from real users in the importance they attach to a defect;Inspectors may have their own preferences, biases and views towards the design of user interfaces or interaction design, which in turn may bias the evaluation data;The evaluation data from inspection is highly dependent on the skills and experience of the inspectors.

Give one mark for each of two benefits and two limitations.

[Total 4 marks]

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(d) Using heuristic evaluation would be useful to detect any ‘obvious’ errors in the interface, and would avoid wasting the time of real users. However, operating this kind of interface is highly skilled and finding a suitable inspector would be difficult because of the specialist knowledge required. In general, real users find it difficult to understand heuristics and so it would not be appropriate to involve a real user. It would be essential to back up heuristic evaluation with user observations. Alternatively, heuristic evaluation may be considered as inappropriate because of the difficulty of finding a suitable inspector.

Give 2 marks for the explanation. Either answer is acceptable, provided it is well-argued. The marks are for the argument, not the answer.

[Total 2 marks]

6


Question 6Listed below are three main preparation tasks to be carried out before running an evaluation session. For each of them, describe what is involved and give one advantage of performing the task:

(i) Producing an evaluation plan [6](ii) Writing an evaluation script [2](iii) Running a pilot test [2]

Sample Solution 6a Producing an evaluation plan involves making choices regarding the evaluation

technique, the participants, the evaluators, task description, and location. The evaluation plan outlines how the evaluation sessions will be conducted. Advantages of producing such a plan include being well-prepared for the sessions, and knowing that all the important decisions have been made.

Describing what is involved in producing an evaluation plan should include each of the five aspects. Give 1 mark for describing each aspect of the evaluation plan, and 1 mark for a suitable advantage.

[Total 6 marks]

b Writing an evaluation script involves writing down the words that will be spoken to each participant, together with instructions, e.g. when to give the consent form etc. An advantage of having a script is that it is easier to remember all the steps in the procedure, and to be consistent with all participants.

Give 1 mark for explaining what an evaluation script is, and 1 mark for a suitable advantage.

[Total 2 marks]

c Running a pilot test involves performing an evaluation session to check that your plan will work. The pilot session is run with participants who are representative of your end users. The advantage of running a pilot session is that you can practice your evaluation materials before the ‘real’ evaluation sessions are run. No matter how much you plan the evaluation session, unexpected events occur, and people will do things you don’t expect.

Give 1 mark for explaining what a pilot session is, and 1 mark for a suitable advantage.

[Total 2 marks]

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Part II (worth 60%)

Question 7In the context of TravelOrganiser, identify six specific considerations that should be taken into account when designing the user interface. Your answers must be drawn from any or all of the following areas.

users tasks the environment

Justify why each consideration is important, and briefly outline how it could be addressed by the user interface design.

[12 marks. 2 marks for each of 6 different issues]

Sample Solution 7Users’ computer experience. There will be a wide variety of computer experience in the user group, so the system needs to be designed with novices and experts in mind.

Users’ physical abilities. Users may be of any age, and of any abilities. The system should be designed with accessibility issues in mind with such a wide variety of potential users.

Users motivation. Users may be highly motivated to sort out their holiday, but they are unlikely to be very patient with a system that takes a long time.

Task regularity. Users are likely to use the system infrequently, possibly only once ever. They will not need to access their data once the session has been completed. TravelOrganiser will need to be easy to use on the first attempt.

Task. Use of the system is likely to be interrupted, but the data would not be kept if the client does not complete the session.

Task. The nature of the task involves a set of simple questions. This would be addressed using menus in a question and answer format.

Environment. The system is to be designed for use in the travel agents, so the environment is likely to be noisy, and possibly dusty. The machine can be placed somewhere to maximise light effectiveness.

Two marks each: one for why each consideration is important in the context of this scenario, and one for how the UI might address it. Chapter 4 offers the following:

User characteristics: age, sex, culture, physical abilities, educational background, computer/IT experience, motivation, attitude.

Task characteristics: variability of task, regularity of tasks, knowledge and skills required, time criticality, safety hazards, alone or with others, task switching.

Environment characteristics: social, physical and organisational.

Students may call on any of these. No marks for answers which don’t pertain to the scenario.

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Question 8(a) Write two brief distinct use scenarios for TravelOrganiser. These should demonstrate

how users would interact with the system. For each, explain the benefits such a system would provide to the user carrying out his task in the particular environment.

[4](b) Suggest two distinct possible input devices, other than the standard QWERTY

keyboard and mouse, and two distinct possible output devices that would be appropriate for TravelOrganiser. For each device, describe its operation and the advantages and disadvantages of its use in this context. [6]

(c) Suggest an appropriate interaction style for this system, again considering the advantages and disadvantages of the suggested interaction style in this context. [2]

Sample Solution 8(a) Johnny Williams is a young bachelor looking for an adventure holiday. He is keen on

most sports and has tried skiing and body-boarding before, but this time is looking for something different. He's not too bothered about where he travels, provided it is somewhere with a lot of people. He has seen WalHal Travel advertised and wants to explore the possibility of having a tailor-made holiday. He walks up to the TravelOrganiser and chooses the option to see some example holidays. These look interesting, but there is nothing particularly exciting for him. He then looks at the options for different activity holidays. Here there is a long list including pot-holing, skiing, surfing, scuba-diving, and many others that Johnny has considered before. Then he spots kite surfing. He has not heard of this before, and so he looks at the description. This appeals to him, and so he then wants to find out where he can go on holiday to do this. Having got the list of places, he prints off his findings and takes them away to find out more about the sport and its locations.The benefit to Johnny is that he is able to find out the kinds of activities on offer, without having to wait in a long queue to meet with the travel agent.Harriet Smith is retired and is looking to have a holiday of a life time. She hasn’t done much travelling in her life, is frightened of flying, and can’t drive. She is also rather shy of talking to travel agents but would prefer to look through printed brochures. Unfortunately most of the holidays she has found in brochures involve flying or driving. She approaches the TravelOrganiser and although she is not very good with computers, she finds the interface appealing and easy to follow. She begins by looking at some example holidays. One of these is a cruise on the Danube. She had considered a cruise before, but had only found holidays involving sea crossings, but she didn’t like this idea. A river cruise sounds much more interesting. In this example holiday, though, the client travelled by air. Harriet doesn’t want to fly, and so she goes to the travel options and finds that she might be able to travel there by train and hydrofoil. She prints off the example holiday and takes it across to the travel representative to discuss her specific options.The benefit to Harriet is that she can take her time to explore the options and then be more confident in talking with the representative.

Two marks per scenario: one for a brief use scenario, and one for the benefits.

[Total 4 marks]

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(b) Input device. Tablet – could be used to input choices.Advantage: easy to use by all levels of expertise.Disadvantage: users with limited dexterity may have difficulty.Touch Screen – to choose the options available on the screen.Advantage – easy to use, no peripherals to get lost or broken.Disadvantage – limit to the number of options that can feasibly be displayed on the screen.Output device. (only two required)Screen – a good quality screen is required to give good color rendition.Advantage – Good for displaying images of hotels and resorts.Disadvantage – Could be expensive if WalHal is a nationwide chain.Printing device – to output a list of choices to take to the agent.Advantage – allows a hard copy to be carried about.Disadvantage – need to keep paper and ink full, and possibility of litter as unwanted printouts are left lying around. Wall-mounted display – a large screen.Advantage – groups of users can comfortably view the information together.Disadvantage – others in the shop can also see the display and this lack of privacy may inhibit the system’s use.

1½ marks each: ½ mark each for naming and brief description; advantage; disadvantage. Note the use of ‘distinct’ in the question. If answer only names the device without any description, this does not get the half mark.

[Total 6 marks]

(c) Interaction styleMenu-based system is likely to be most appropriate. Advantage: easy to guide users through the material. Disadvantage: unlikely to be able to include all the possible options and users may get a wrong impression of how many options are possible.

Only one interaction style is required. Just naming the interaction style gets nothing.

Give 1 mark for advantage and 1 mark for disadvantage. The answer must be linked to context, but if the context is implicit in this answer, and it has clear links to thinking from earlier parts of the question, then this is acceptable. The advantages and disadvantages must refer to the interaction style and not the hardware.

[Total 2 marks]

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Question 9Draw and annotate aspects of the TravelOrganiser user interface, to illustrate how to apply design principles and guidelines.

Identify in your drawings six distinct examples of the application of principles and guidelines.

For each example:

(a) State in full which principle or guideline is being applied. This principle/guideline should relate to one of the following areas:

Simplicity, structure, consistency or tolerance The psychological characteristics of users Metaphor, text, color, images, moving images or sound The layout GUI / Web /embedded systems

(b) Briefly explain how the application of the principle/guideline makes the user interface more usable, mentioning the users, tasks and environment as appropriate.

[12 marks, 2 for each example ]

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Sample Solution 9I have included two screens: one for choosing existing holiday packages, and one for looking at the choices available.

Example holidays

Adventureclimbing in the Pyreneesskiing in Coloradowhite water rafting in North Carolina

Relax by the Indian OceanHistorical tours of Egypt

See choices so farBack to main menu

What kind of holiday would you like?

Type of Accommodation ... Type of Location ...Type of Holiday

Adventure Coach tourActivity …

Facilities Available ...

See choices so f arBack to main menu

Buttons should be large, easy target. The menu options and the screen buttons are large and easily targetted.

Place command buttons along the bottom of the dialog box. Command buttons are consistently placed at the bottom of the screen.

The menu should be organised around the needs of the users rather than around the underlying software. These options are intended to support the users’ needs not the software developers’

Screens should be kept uncluttered. The menu options can be expanded by clicking on the three dots to the right of the menu item. In this example, type of holiday has been expanded. This makes the more of screen space.

Use images to good effect. The images next to the options in the menu help to clarify what the user can expect when they choose an option. (I couldn’t get very good ones, but imagine that they are photos of where the holiday would be)

Screens should be consistent. Both screens have the same two buttons at the bottom of the screen, and the title block at the top. This makes it clear for novice users.

Give two marks for each example. This should be one for naming the principle/guideline in full e.g. simple layout; one for why it improves usability in this case.

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Question 10In the context of TravelOrganiser, assume that you are carrying out user observations on a prototype.

You may choose whether the prototype is high or low fidelity, but you must explicitly state your choice, and refer to your choice, where appropriate, in answering the following.Plan your user observations with respect to the following aspects:

(a) examples of the type of data you wish to collect and how you would collect it. [4](b) the constraints you are likely to be working under in conducting the user observations.

[2](c) how you would apply the evaluation elements. [2](d) who you would choose as participants. [2](e) the location you would choose for the evaluation. [2]

Sample Solution 10This refers to a high fidelity prototype

(a) The interface should be clear and easy to understand and use. This is particularly important for members of the public with motor or visual disabilities. This could be tested by showing screens to representative users and timing how long it takes for them to find specific options. It could also be tested by asking them for their opinions after performing some tasks.The system should display information within a reasonable time frame. This could be tested by timing how long it takes for information to be displayed.

For each of two requirements, give one mark for a clear statement of it and one mark for the corresponding discussion of data type and collection.

[Total 4 marks]

(b) Finding a representative group of users willing to take part, and paying them.Preparing sufficient test data, with holiday examples, and a number of choices and options.

Give one mark for each of two sensible constraints. Note that these are constraints on the user observations not on the buying or development of the system.

[Total 2 marks]

(c) Observe – users using the system.Compare – the system with the users’ perceptions of what would be helpful to them.Measure – satisfaction by way of a SUMI questionnaire; number of errors, number of times a particular error is made; number of users who became stuck or used ‘undo’ command.Listen – to users’ comments as they use the system.

Give 1/2 for each element: check that the answers are consistent with both their answer in (a) and the fidelity of the prototype e.g. time taken for doing tasks would probably not be relevant for a low fidelity prototype.

[Total 2 marks]

(d) It is vital to choose participants from the intended user population. At least one young person (under 16) and one older person (over 70), and one person around 40, combined with novice versus experienced computer users.

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Give 1 mark for representatives from each user population in the scenario. No substitute users are acceptable.

[Total 2 marks]

(e) Location. A busy environment that would simulate the travel agents’ offices.[Total 2 marks]

NB: the answers should be integrated, that is, all pertain to the same usability requirements.

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Question 11(a) For the development of TravelOrganiser, what level of usability maturity is your

manager likely to be at? Justify your answer. [2]

(b) In the context of TravelOrganiser, you need to persuade your manager that usability and user-centred design are important. Describe, giving examples, two distinct methods that you could use. For each method, explain an advantage to its use in this context and describe one potential difficulty that might arise. [4]

(c) In order to develop the user interface in a user-centred way, you need to identify the stakeholders. In the context of TravelOrganiser, who would be the main beneficiaries, decision-makers and workers (excluding the development team)? Justify your choices.

[6]

Sample Solution 11(a) The manager is likely to be at curiosity or acceptance. The organisation has not

employed a full-time usability specialist before, but they are aware of the importance of usability, so is not sceptical or partnership.

Give 1 mark for curiosity or acceptance and 1 mark for a justification. An answer other than these can attract a maximum of 1 mark.)

[Total 2 marks]

(b) You could give the manageress the system and ask her to explore holiday options for herself. You would then be able to illustrate the kinds of feedback possible from a real user of the system.You could invite the manageress along to a user test session and hear the comments from the users, specifically how it has helped them achieve something they could never have done otherwise.

Give 2 marks for each argument. Answers must be tied to the context of TravelOrganiser. Generic answers such as snapshot reports must show their advantages/disadvantages within this context. Any argument not grounded in the scenario gets a maximum of 1 mark.

[Total 4 marks]

(c) The direct beneficiaries are the clients. Indirectly, WalHal representatives as they will have more information to start with when talking with the client. The shareholders of WalHal should also benefit as they will hopefully sell more holidays.The decision makers are primarily the management of WalHal.Workers: these are defined in the glossary as ‘a stakeholder whose workload may increase because of a project, or who perceives that it may increase’. The users are one type of worker. Apart from the system developers, everyone else’s workload should decrease as clients will be able to make some decisions without taking up the representatives’ time.

Give 1 mark for each correctly-identified stakeholder. The answer should include at least one type of person in each category.

[Total 6 marks]

[END OF SOLUTIONS]

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