Copyright Chris Johnson, 2003.
Xday, XX August 2003.

00:00 am - 00:00am



University of Glasgow





DEGREES OF BEng, BSc, MA, MA (SOCIAL SCIENCES).





COMPUTING SCIENCE - 3W:
Interactive Systems 3 (Resit)

(Answer one question from Section A and one question from Section B).




Section A (Chris' Questions)

1.

a) Briefly explain why even expert users can get 'lost in hyperspace'.

[5 marks]

[seen problem] This is a starter question and should be relatively straightforward. Experts can get lost in hyperspace because of the complexity of some sites. They may not have visited all of the pages/areas of more complex sites. Hence they can resemble novices in some respects. Knowledge of search and navigational tools can help experts in this situation but if they are missing or poorly designed then experts will still become lost. Couple these comments with an appreciation of the dynamism of many sites, experts with a previous version may have limited understanding after an update.

b) A recent survey of over 400 e-commerce sites found that just fewer than 50% provided a site map. In another usability study, it has been found that users make an unintended or 'incorrect' selection for every three items chosen from a site map. In other words, there is a one in three chance that the site map will not take them where they want to go. Briefly comment on the implications that these results carry for the design of site maps. Identify an alternative to a site map as a means of supporting user navigation of large web sites.

[10 marks]

[seen problem] Firstly, attention must be paid to encourage users to find and exploit site maps given that this is not a routine activity. Links should appear in a consistent location and it should be clear what they refer to if icons or other annotations are used. Alternatively, it can be argued that the low usage implies designers should assume the site map will not be used and conduct evaluations to reflect this by deliberately running tests that deny access to this facility. The relatively poor performance of site maps in directing users to relevant pages implies the need for user testing, possibly using card sorting techniques mentioned below. Designers must also consider the range of different users and their tasks if they are to have any hope of predicting/optimising the design of a site map to support navigation on a complex site.

c) You have been asked by an Internet bank to work on two different site maps. The first is intended to support the banks customers to navigate the facilities that are provided on the public site. The second is intended to support bank employees to navigate through areas of the Bank's Intranet. Write a brief technical report describing the important differences that exist between these two different maps. Clearly identify any differences that you would make in the design of these maps.

[12 marks]

[seen problem] Intranet users within the bank will be familiar with the terminology used in the organisation. They may also understand the organisational structure of the bank. They are likely to use the site more often and have greater navigational expertise within some areas. This can simplify the design task because greater assumptions can be made about prior knowledge. However, changes to the site map will be noticed quickly and could have an immediate implication for operation efficiency. It may, therefore, be necessary to conduct trials across the organisation to identify any adverse effects from changes rather than risk the negative business impact if employees cannot find necessary information. By changes here we include both alterations to the site map and changes to the underlying content. In terms of design, I would consider optimising site maps for sub-groupings within the organisation. The level of detail on the structure of pages provided in a site map would be focussed according to the group tasks with pages relating to other areas of the Intranet only shown in summary unless more detail was specifically requested.

In contrast, customers are unlikely to use the site every day. They will be unfamiliar with the organisation of the bank and arguably can also be drawn from more diverse social and education groupings than the banks employees. This makes testing more difficult because designers would have to consider what the 'typical' sample of customers/users should be. Changes are less likely to be business critical but may have a prolonged impact as users come across new facilities over a long period of time hence designers may need to monitor longitudinal changes in customers' navigational behaviour. In terms of design, an ideal solution would be to alter the level of detail in the site map to reflect increasing exposure to the site by monitoring/logging previous customer interactions. Changes should also be limited to build up familiarity with the site map even if the underlying site changes more often.

 

2.

a) Briefly describe how card--sorting techniques can be used to support requirements elicitation for the design of web-based information systems.

[4 marks]

[seen problem] A card can represent each web page or portion of a web page. Users are then encouraged to sort the cards that belong together. The precise instructions that are given can depend upon the purpose of the elicitation. They can be open ended as in the previous description or additional 'steers' can be provided. For example, they might be told that 'supposing you are finding information on the accounts department, order the information according to relevance<85>'. An appropriate sample of users must conduct the sorting. Correlations can then be calculated to determine the strength of any associations. Care must also be taken to understand the reasons why groupings exist <96> otherwise designers can identify inappropriate labels for the meta-level categories/pages.

b) Why is it hard to use these techniques to support the design of sites that focus more on subjective satisfaction and entertainment than on task-based interaction?

[6 marks]

[Unseen problem] It is hard to use standard card sorting for applications such as games. Many of these applications rely upon affect that plays on the grouping of pages. For example, designers can deliberately surprise users by providing links between sections that users may not have anticipated. Alternatively, there can be a sense of exploration where the ultimate end of the game is not apparent to the user during their interaction. Derivatives of the early Myst game provide an example of this. Page orderings may also change over time to give the impression that each interaction with the site is a new 'experience'.

Further problems stem from the very diverse user populations for many entertainment-based sites. There can be a wide range of ages and of backgrounds looking at sites such as Sony or Disney. Their tasks can also range widely from gathering details about a particular entertainment product through to playing on-line games in the manner mentioned in the previous paragraph. This diversity makes it likely that there will be disagreement and conflict in the results of any card sorting. Asking someone over the age of 40 to assign a category to pages on ble-blades may not be sensible.

These contrasts should not obscure further similarities with information-based systems. It is still important that people can access intended resources on entertainment sites, such as BBCOnline. Hence the argument is not that card sorting cannot be used in these applications but that it raises more problems and that the results should be regarded with caution.

c) Your manager has asked you to show that a web site is "accessible to the broadest cross-section of users possible". Write a brief technical report describing how you would go about satisfying this demand.

[15 marks]

[seen problem] This is a slight trick question. I would try to persuade the manager of the difficulties of achieving their stated objective. The broadest cross-section can only be defined in terms of the resources that are available to an evaluation. For example, tests should be conducted for users with access to a range of different technical resources ranging from different browsers and modem connections through to display resolutions and input devices. Similarly, evaluations can be conducted on users with different characteristics, age, disability, education level and computational expertise etc. Tests can be conducted in groups or in different contexts of use. These might include users from different geographical regions and cultures. Given the costs associated with a formal evaluation on any group of users in a particular setting, I would advise the use of more subjective and qualitative techniques. The reduced costs can, however, be offset by the difficulty of interpreting the validity of results from questionnaires, heuristic evaluation for accessibility, think alounds and focus groups. Hence it might be better to rephrase the assignment as identifying the best mix of techniques to determine the 'usability' of a site for the widest group of users within a particular budget.

Alternatively, I would try to persuade the manager to prioritise key user populations. Greatest effort would be focussed on the most important groups. Fewer resources could be used to assess usability for more diverse groups. This creates problems when management face competing accessibility requirements and risks the dangers of tokenism when ensuring accessibility for disabled users.

First class answers might refer to the development of automatic assessment tools. I've introduced them to the NIST accessibility tool set and have discussed their current limitations. Page 2 of 5

Initial development can be further informed by formative evaluation as users attempt to perform common tasks on prototype implementations. This can be problematic as it is likely that the initial versions of a site will be tailored to more obvious tasks. These evaluations are likely to determine whether the site fails to support any less obvious tasks that may have been missed during the initial elicitation. It can be difficult to interpret response to 'have we missed anything' questions. This can provoke a lengthy wish list or a minimal response based on a lack of knowledge about what might be possible.

Once the site goes live, the subjective satisfaction techniques, mentioned in the previous parts of this question, can be used to assess whether the site meets expectations. Again, however, the summative use of these techniques is not particularly well tailored to identify missing functionality. More specific facilities can be introduced so customers can provide feedback on their use of the site. This increases the salience of item 9 in the previous list. Any testing strategy should not stop with summative evaluation but continue into site support and maintenance¬Ö


Section B (Rob's Questions)

3. Question on second half of the course.

[Total 25 marks]

4. Question on second half of the course.

[Total 25 marks]


[end]