人機交互考試幾個大題的問題及答案

1、The user control guideline states that, 'The user, not the computer, initiates and controls all actions.'In the case of dialog boxes, this guideline is clearly contradicted. A dialog box can be used to indicatewhen an error occurs in the system. Once this error has been detected and presente

2、d 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 box.The system preempts the user dialog, with good reason. The preemptive nature of the dialog box is to ensurethat the user actually notices that there was an error. P

3、resumably, the only errors that will be producedin such an intrusive manner are ones which the user must know about before proceeding, so the preemptionis warranted. But sometimes dialog boxes are not used to indicate errors and they still prevent the userfrom performing some actions that they might

4、 otherwise wish to perform. The dialog box might be asking theuser to fill in someinformation to specify parameters for a command .If the user does not knowwhat 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

5、, but in order to do that they must exit the dialog box (and forfeit any of the settingsthat they might have already entered), 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

6、prevent,but it doesn't always get applied.answerThe discussion of consistency suggested that it can take many forms, because it is usually referred to in relation to some other feature of the interaction between user and system. Mentioned already in the textwe have consistency related to the fol

7、lowing principles:Familiarity - consistency with respect to prior real-world experienceGeneralizability - consistency with respect to experience with the samesystem or set of applications on the same platformIn addition, we could interpret some other principles as contributors to consistency:Afforda

8、nce - consistency with understood intrinsic properties of an object, so a soft button onthe screen should allow us to always 'push' on it to select some actionPredictability - consistency of system response with user's expectation, given the user has someinformation about past interactio

9、n historySubstitutivity - consistent permission from system to allow use of equivalent values for input and outputCommensurate effort - consistency of effort with respect to doing and undoing tasksResponse time stability - consistency of system response for similar actionsSome other principles for c

10、onsistency from the text and elsewhere:Consistency can be relative to the form of input/output expressions relative to the 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 typewrite

11、r keys that form a diagonal to indicate up, down, left and right information for an input command).As discussed in the exercise on colour, consistency can be with respect to social or cultural conventions ., using red to indicate stop or hot, green for go, blue for cool).EXERCISEChoose an appropriat

12、e evaluation method for each of the following situations. In each case identify(i) The participants.(ii) The technique 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 d

13、esign of a spreadsheet package and you wish to test what type of icons will be easiest to learn.(b) You have a prototype 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

14、it before release.(d) You have developed a group decision support system for a solicitor's office.(e) You have 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

15、 are illustrative; there are many possible evaluation techniques that could be appropriate to the scenarios described.Spreadsheet package(ii) TechniqueHeuristic evaluation(i) SubjectsTypical users: secretaries, academics, students, accountants, home users,schoolchildren(iii) RepresentativeSorting da

16、ta, printing spreadsheet, formatting cells, adding functions, producingtasksgraphs(iv) MeasurementsSpeed of recognition, 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) SubjectsT

17、heatre-goers, the general public(ii) TechniqueThink aloud(iii) RepresentativeFinding next available tickets for a show, selecting seats, changing seats, changingtasksdate of booking(iv) MeasurementsQualitative measures of users' comfort with system, measures of cognitive complexity, quantitative

18、 measures of time taken to perform task, errors made(v) Outline planPresent users with prototype system and tasks, 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, typica

19、l profile shouldbe determined for the gamein advance and the test users should be selected from this population, plus a few from outside to see if it has wider appeal(ii) TechniqueThink aloud(iii)Whatever gameplay tasks there are - character movement, problem solving, etc.Representative tasks(iv) Me

20、asurements Speed of response, scores achieved, extent of game mastered.(v) Outline planAllow subjects to play gameand 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(i) Su

21、bjectsSolicitors, legal assistants, possibly clients(ii) TechniqueCognitive walkthrough(iii) RepresentativeAnything requiring shared decision making: compensation claims, plea bargaining,taskscomplex issues with a diverse range of expertise needed.(iv) MeasurementsAccuracy of information presented a

22、nd accessible, veracity of audit trail of discussion, screen clutter and confusion, confusion owing to turn-taking protocols(v) Outline planEvaluate by having experts walk through the system performing tasks, commenting as necessary.Exam result management(i) SubjectsExams officer, secretaries, acade

23、mics(ii) TechniqueThink aloud, questionnaires(iii) RepresentativeStoring marks, altering marks, deleting marks, collating information, securitytasksprotection(iv) MeasurementsEase of use, levels of security and error correction provided, accuracy of user(v) Outline planUsers perform tasks set, with

24、running verbal commentary on immediate thoughts andconsidered views gained by questionnaire at end.EXERCISEWrite a manual page for making a cup of coffee. Assume your user has no experience but will recognize a cup.a kettle, a spoon, etc. Swap your manual with a partner. Does your partner's manu

25、al give you sufficient instruction to make the cup of coffee Discuss improvements with your partner and agree on a final versionof the manual.answerFirst you have to decide upon the level of granularity at which you are going to work. The aim of the exerciseis to demonstrate that it is not as straig

26、htforward as it might seem to provide instructions even for a veryfamiliar and well-understood task. Given this, it is most helpful to assume that the user knows very little.The example solution (Table assumes that the user will recognize objects (perhaps they are labelled) andunderstands common act

27、ions and directions, but not the specific actions required here. Alternatively youcould choose to assume that the user does know how to turn on a tap and open a jar.The two options could be expanded further if required. Other alternatives could be included, such as gettingwater from another source.M

28、anual for making a cup of coffeeRequired:an automatic electric kettle, a jar of instant coffee powder or granules, a mug, a teaspoon, a mains water tap (or an alternative source of water), a mains electricity supply, milk (optional), sugar (optional).CAUTION:Electricity can be dangerous - avoid any

29、contact between electric connections and water.Boiling water can scald - take care.To boilEnsure plug on kettle is not connected to mains electricity supply.Remove lid from kettle.water:Place kettle directly beneath spout of tap.Turn tap handle anticlockwise to release water.Whenwater reaches mark l

30、abelled 'full'on kettle turn tap handle clockwise to close off watersupply.Replace kettle lid.Move kettle to proximity of mains electricity supply.Placekettle's plug into electricity socket.Press button marked 'on' on top of kettle to switchkettle on.When the water has boiled, th

31、e kettle will switch off automatically and the 'on'button will return to its originalposition with a click.Remove<ettle'splug from electricitysocket.To makeTake jar of coffee and remove lidby turning anticlockwise.Fill teaspoon with coffee.Placecoffee:contents of teaspoon in cup.Repla

32、ce lid on coffee jar and turn clockwise to tighten.Pourboiling water from the kettle into the cup up to approximately 1/2 an inch from the top.Addmilk if required (to almost fillcup).Add sugar if required.Stir coffee mixture withspoon.The coffee is now ready to drink.Table-Coffee making manualThe di

33、scussion should focus on the assumptions that are made. You should make a conscious decision aboutwhat 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. How useful do you feel task analysis is