人機交互考試幾個大題的問題及答案

1、EXERCISE 7.5Can you think of any instances in which the user control guideline suggested by Apple is not followed? (Hint: Think about the use of dialog boxes.)answerThe user control guideline states that, 'The user, not the computer, initiates and controls all actions.' In the case of dialog

2、 boxes, this guideline is clearly contradicted. A dialog box can be used to indicate when an error occurs in the system. Once this error has been detected and presented to the user in the dialog box, the only action that the system allows the user is to acknowledge the error and dismiss the dialog b

3、ox. The system preempts the user dialog, with good reason. The preemptive nature of the dialog box is to ensure that the user actually notices that there was an error. Presumably, the only errors that will be produced in such an intrusive manner are ones which the user must know about before proceed

4、ing, so the preemption is warranted. But sometimes dialog boxes are not used to indicate errors and they still prevent the user from performing some actions that they might otherwise wish to perform. The dialog box might be asking the user to fill in some information to specify parameters for a comm

5、and. If the user does not know what to provide, then they are stuck. A lot of the time, the user can find out the information by browsing through some other part of the system, but in order to do that they must exit the dialog box (and forfeit any of the settings that they might have already entered

6、), find out the missing information and begin again. This kind of preemption is not desirable. It is probably this kind of preemption the user control guideline is intended to prevent, but it doesn't always get applied.EXERCISE 7.27.2 It has been suggested in this chapter that consistency could

7、be considered a major category of interactive principles, on the same level as learnability, flexibility and robustness. If this had been the case, which principles discussed in this chapter would appear in support of consistency?answerThe discussion of consistency suggested that it can take many fo

8、rms, because it is usually referred to in relation to some other feature of the interaction between user and system. Mentioned already in the text we have consistency related to the following principles:Familiarity- consistency with respect to prior real-world experienceGeneralizability- consistency

9、 with respect to experience with the same system or set ofapplications on the same platformIn addition, we could interpret some other principles as contributors to consistency:Affordance- consistency with understood intrinsic properties of an object, so a soft button on the screen should allow us to

10、 always 'push' on it to select some actionPredictability- consistency of system response with user's expectation, given the user hassome information about past interaction historySubstitutivity- consistent permission from system to allow use of equivalent values for inputand outputCommen

11、surate effort- consistency of effort with respect to doing and undoing tasksResponse time stability- consistency of system response for similar actionsSome other principles for consistency from the text and elsewhere:Consistency can be relative to the form of input/output expressions relative to the

12、 user's conceptual model of the system. An example in the text involves using keys whose relative positions are similar to commands for the systems (any set of four typewriter keys that form a diagonal to indicate up, down, left and right information for an input command).As discussed in the exe

13、rcise on colour, consistency can be with respect to social or cultural conventions (e.g., using red to indicate stop or hot, green for go, blue for cool).EXERCISE 9.4Choose an appropriate evaluation method for each of the following situations. In each case identify(i) The participants.(ii) The techn

14、ique used.(iii) Representative tasks to be examined.(iv) Measurements that would be appropriate.(v) An outline plan for carrying out the evaluation.(a) You are at an early stage in the design of a spreadsheet package and you wish to test what type of icons will be easiest to learn.(b) You have a pro

15、totype for a theatre booking system to be used by potential theatre-goers to reduce queues at the box office.(c) You have designed and implemented a new game system and want to evaluate it before release.(d) You have developed a group decision support system for a solicitor's office.(e) You have

16、 been asked to develop a system to store and manage student exam results and would like to test two different designs prior to implementation or prototyping.answerNote that these answers are illustrative; there are many possible evaluation techniques that could be appropriate to the scenarios descri

17、bed.Spreadsheet package(i) SubjectsTypical users: secretaries, academics, students, accountants, home users, schoolchildren(ii) TechniqueHeuristic evaluation(iii) RepresentativeSorting data, printing spreadsheet, formatting cells, adding functions,tasksproducing graphs(iv) MeasurementsSpeed of recog

18、nition, accuracy of recognition, user-perceived clarity(v) Outline planTest the subjects with examples of each icon in various styles, noting responses.Theatre booking system(i) SubjectsTheatre-goers, the general public(ii) TechniqueThink aloud(iii) RepresentativeFinding next available tickets for a

19、 show, selecting seats, changing seats, changingtasksdate of booking(iv) MeasurementsQualitative measures of users' comfort with system, measures of cognitive complexity, quantitative measures of time taken to perform task, errors made(v) Outline planPresent users with prototype system and tasks

20、, record their observations whilst carrying out the tasks and refine results into categories identified in (iv).New game system(i) SubjectsThe game's target audience: age, sex, typical profile should be determined for the game in advance and the test users should be selected from this population

21、, plus a few from outside to see if it has wider appeal(ii) TechniqueThink aloud(iii)RepresentativeWhatever gameplay tasks there are - character movement, problem solving, etc.tasks(iv)MeasurementsSpeed of response, scores achieved, extent of game mastered.(v) Outline planAllow subjects to play game

22、 and talk as they do so. Collect qualitative and quantitative evidence, follow up with questionnaire to assess satisfaction with gaming experience, etc.Group decision support system(ii) TechniqueCognitive walkthrough(iii) RepresentativeAnything requiring shared decision making: compensation claims,

23、plea bargaining,taskscomplex issues with a diverse range of expertise needed.(iv) MeasurementsAccuracy of information presented and accessible, veracity of audit trail of discussion, screen clutter and confusion, confusion owing to turn-taking protocols(v) Outline planEvaluate by having experts walk

24、 through the system performing tasks, commenting as necessary.Exam result management(i) SubjectsExams officer, secretaries, academics(ii) TechniqueThink aloud, questionnaires(iii) RepresentativeStoring marks, altering marks, deleting marks, collating information, securitytasksprotection(iv) Measurem

25、entsEase of use, levels of security and error correction provided, accuracy of user(v) Outline planUsers perform tasks set, with running verbal commentary on immediate thoughts and considered views gained by questionnaire at end.EXERCISE 11.1Write a manual page for making a cup of coffee. Assume you

26、r user has no experience but will recognize a cup, a kettle, a spoon, etc. Swap your manual with a partner. Does your partner's manual give you sufficient instruction to make the cup of coffee? Discuss improvements with your partner and agree on a final version of the manual.answerFirst you have

27、 to decide upon the level of granularity at which you are going to work. The aim of the exercise is to demonstrate that it is not as straightforward as it might seem to provide instructions even for a very familiar and well-understood task. Given this, it is most helpful to assume that the user know

28、s very little. The example solution (Table Ex11.1) assumes that the user will recognize objects (perhaps they are labelled) and understands common actions and directions, but not the specific actions required here. Alternatively you could choose to assume that the user does know how to turn on a tap

29、 and open a jar.N.B. The two options could be expanded further if required. Other alternatives could be included, such as getting water from another source.Manual for making a cup of coffeeRequired:an automatic electric kettle, a jar of instant coffee powder or granules, a mug, ateaspoon, a mains wa

30、ter tap (or an alternative source of water), a mains electricity supply, milk (optional), sugar (optional).CAUTION:Electricity can be dangerous - avoid any contact between electric connections and water. Boiling water can scald - take care.To boil water:Ensure plug on kettle is not connected to main

31、s electricity supply.Remove lid from kettle.Place kettle directly beneath spout of tap.Turn tap handle anticlockwise to release water.When water reaches mark labelled 'full' on kettle turn tap handle clockwise to close off water supply.Replace kettle lid.Move kettle to proximity of mains ele

32、ctricity supply.Place kettle's plug into electricity socket.Press button marked 'on' on top of kettle to switch kettle on.When the water has boiled, the kettle will switch off automatically and the 'on' button will return to its original position with a click.Remove kettle's

33、plug from electricity socket.To make coffee:Take jar of coffee and remove lid by turning anticlockwise.Fill teaspoon with coffee.Place contents of teaspoon in cup.Replace lid on coffee jar and turn clockwise to tighten.Pour boiling water from the kettle into the cup up to approximately 1/2 an inch f

34、rom the top.Add milk if required (to almost fill cup).Add sugar if required.Stir coffee mixture with spoon.The coffee is now ready to drink.Table Ex11.1- Coffee making manualThe discussion should focus on the assumptions that are made. You should make a conscious decision about what assumptions to make, rather than making them by default. This should ensure that the assumptions that are made are appropriate to the particular user.You could also contrast your answers here, based on the material in this chapter, with the 'making tea' manual in Chapter 15.