Category Archives: Human Behaviour

Of Chocolate and Human Factors

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Chocolate

Not All Chocolate Is Created Equal

My final week discussing Dix 2010 [1] which I covered last week, and the week before that too. Now lets:

imagine you have a group of children and want to give them lunch. In the UK you might well choose baked beans. Not the most exciting choice, but few children actively dislike baked beans; they are acceptable to everyone. However, give each of those children a euro (or maybe two) in a sweet shop … they will all come away with a different chocolate bar, the chocolate bar that is ‘OK’ for everyone gets chosen by none. Much of traditional HCI design is like baked beans – a word processor installed for the whole company, a mail program used by every student, good enough for everyone. However, increasing personal choice, especially for web-based services, makes design more like the chocolate bar; different people make different choices, but what matters is that the product chosen is not ’good enough’ for all of them, but best for some.

Now I’ve covered this in my 2007 paper discussion [2] and Dix has a very good point. I think that the salient point here is that systems run in a combinatorial way, where as individual findings can exist with minimal confounding variables muddying the waters.

Different operating modalities are useful for providing a personalised experience and a one-size fits all approach is not the way forward. Indeed, I wonder if universal design, or participatory design just encourage a product which is acceptable to all but desired by none.

References

  1. Dix, A. (2010). Human–computer interaction: A stable discipline, a nascent science, and the growth of the long tail Interacting with Computers, 22 (1), 13-27 DOI: 10.1016/j.intcom.2009.11.007
  2. Simon Harper (2007). Is There Design-For-All? Universal Access in the Information Society, 6 (1), 111-113 : http://dx.doi.org/10.1007/s10209-007-0071-2

Behavioural Stratergies of Visually Disabled ‘Surfers’ [#accessibility #a11y]

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Basque Government Crest

Basque Government Crest

The World Wide Web (Web) is a crucial resource for the employment, social networking, and entertainment of visually disabled1 users. However, Web pages are designed for visual interaction, and badly built pages, or those transformed into alternative forms (e.g, audio) by assistive technologies, loose the richness of the visual presentation and structural formatting, thereby becoming inaccessible. Our previous studies  suggest that visually disabled users encounter two types of problem: those which are expected and can be adapted to, and those which are difficult and stressful, and can only be handled by coping.

Adaptation strategies include routine, even automatic, modes of getting along, whereas coping strategies are problematic adaptations that require new responses or special efforts; seen as last–resort activities signified by increased stress, increased frustration, increase browse time, increased task completion time, or an inability to interact with the page. We believe that adaptation is a perfectly acceptable mechanism for addressing change, however, we see coping as being driven by the need to address inadequacies in the technology in an attempt to re-engage with the content and re-attain the richness of the visual format.

We understand that the extent of our work will be, to some degree, determined by the ongoing results of the study. Nevertheless, our objective is to develop a deep understanding of how visually disabled users cope with inaccessible Web pages to facilitate more effective accessibility interventions such that the need to cope is removed.

In this case, we believe that the only way to accurately capture these strategies is by a longitudinal ethnographic study in co-operation with our observational partners. Augmented with a remote analysis of the mailing lists and discussion forums in which we have previously seen possible behavioural strategies exchanged.

Well at least that’s what I wrote in the funding application – really as a continuation to Yeliz Yesilada’s initial work and its continuation in Darren Lunn’s CASTA – ‘Coping Strategy Analysis to Support Transcoding Algorithms’ – work [1, 2, 3, 4, 5] . I’m pleased to say that the Basque Government liked it and now Markel Vigo is taking up a research position spending two years with us here in Manchester and then a final year with Julio Abascal at the University of the Basque Country.

Footnotes

  1. The term visually disabled refers to all those people who have either little or no vision or restricted vision not corrected by human artifice.

References

  1. Darren Lunn and Eleni Michailidou and Simon Harper (2007). Observational Notes Acquired from Henshaws’ Skillstep to Success Class: Observation Period 1 WEL Technical Reports, SADIe Technical Report 5 (61) Other: http://wel-eprints.cs.manchester.ac.uk/61/
  2. Darren Lunn and Eleni Michailidou and Simon Harper (2008). Observational Notes Acquired from Henshaws’ Skillstep to Success Class: Observation Period 2 WEL Technical Reports, SADIe Technical Report 8 (64) Other: http://wel-eprints.cs.manchester.ac.uk/64/
  3. Darren Lunn (2008). Verification of The Coping Strategy Framework Through An Analysis of the NoVA Evaluation Data WEL Technical Reports, SADIe Technical Report 10 (67) Other: http://wel-eprints.cs.manchester.ac.uk/67/
  4. Darren Lunn (2008). Coping Strategy Pattern Identification: An Analysis of the Henshaws’ and NoVA Data WEL Technical Reports, SADIe Technical Report 11 (69) Other: http://wel-eprints.cs.manchester.ac.uk/69/
  5. Darren Lunn (2009). Towards Behaviour-Driven Transcoding of Web Content Through an Analysis of User Coping Strategies WEL Technical Reports, Thesis (127) Other: http://wel-eprints.cs.manchester.ac.uk/127/

Visual Complexity Rankings and Accessibility Metrics – #accessibility #a11y

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Visual Complexity Scores - Trendlines

Visual Complexity Scores - Trendlines

Eleni Michailidou passed here PhD defence with flying colours and now her work ‘Visual Complexity Rankings and Accessibility Metrics’ is published. I’ll let her abstract tell the story but this is some really interesting work.

The World Wide Web (Web) has become the major means of distribution and use of information by individuals around the world. Web page designers focus on good visual presentation to implicitly help users navigate, understand, and interact with the content. The rapid and constant advancement of technology introduced new ways to present information that leads to visually complex Web pages. Problems arise, though, for people with disabilities, especially those who are visually impaired, because implicit visual cues presented on a Web page can- not be accessed and used.
We assert that, identifying the areas that are complex for sighted users will have direct benefits for blind and visually impaired users. We theorise that by understanding sighted users’ visual perception of Web page complexity we can understand the cognitive effort required for interaction with that page. This is an important contribution to the Web accessibility area because by using visual complexity, an identifiable measure, as an implicit marker of cognitive load, Web pages can be designed that are easier to interact with.
Results from user evaluations provided statistical models that, based on the density and diversity of Web page structural elements (such as text, tables, and images), can significantly predict sighted users’ perception of Web page visual complexity. The framework is then implemented into the ACTF Eclipse frame- work by extending the aDesigner accessibility tool to the ViCRAM tool. The tool automatically analyses a Web page with respect to its visual complexity. For each Web page a complexity score, that determines the page’s level of visual complex- ity, and an overlay heatmap, that mimics a user’s visual complexity perception by noting the areas that are most visually complex, are generated.
A user and technical evaluation support our assertions and show that the tool can significantly predict the level of visual complexity of a Web page. Therefore, users can have an initial perception of the visual layout of the page and designers can use this framework to balance Web page visual complexity with usability and accessibility.

Be careful, her PhD Thesis is a 250 page – 30Mb brute – but everything is in there! Thanks to Prof Stephen Brewster and Dr Steve Pettifer for the viva examination.

ResearchBlogging.org
Eleni Michailidou (2010). Visual Complexity Rankings and Accessibility Metrics PhD Thesis

ASSETS 2010 Picks – #assets10

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ResearchBlogging.orgWe did present at ASSETS 2010 as I previously said and I must say that I think this years conference was solid. Maybe the work presented was not completely within my frame of interest; indeed, there was Rehabilitation Engineering, Assistive Technology, Educational, and advocacy work there which are interesting but for me not directly relevant. However, there were a couple of papers that did in principle offer the promise (if not yet realised) of being transformative, and providing some good solid scientific understanding.

The first was Shari Trewin’s [1] work which undertook a study of screen reader users and then attempted to add that model to the CogTool system. This means that it may become useful for user prediction in the future, but more rigours models are currently still required. The work puts me in mind of IBMs aDesigner which is now part of the eclipse AcT Framework, but Trewin’s work seems to lend itself far more to task based analysis of user behaviour…

Designers often have no access to individuals who use screen reading software, and may have little understanding of how their design choices impact these users. We explore here whether cognitive models of auditory interaction could provide insight into screen reader usability. By comparing human data with a tool- generated model of a practiced task performed using a screen reader, we identify several requirements for such models and tools. Most important is the need to represent parallel execution of hearing with thinking and acting. Rules for placement of cognitive operators that were developed for visual user interfaces may not be applicable in the auditory domain. Other mismatches between the data and the model were attributed to the extremely fast listening rate and differences between the typing patterns of screen reader usage and the model’s assumptions. This work in- forms the development of more accurate models of auditory inter- action. Tools incorporating such models could help designers create user interfaces that are well tuned for screen reader users, without the need for modeling expertise.

BumpTop Desktop View

BumpTop Desktop View

Next up was some work on desktop metaphors for older users by Nic Hollinworth and Faustina Hwang [2]. This work is still at an early stage but it does seem to have some potential, a fact which is not lost on Google – as they have just purchased BumpTop; which is a 3D representation of a desktop using real life metaphors to help organise the work. Now Nic’s work has some difference to BumpTop and seems to be far more like the real world, making interaction by older users more intuitive…

Routine computer tasks are often difficult for older adult computer users to learn and remember. People tend to learn new tasks by relating new concepts to existing knowledge. However, even for ‘basic’ computer tasks there is little, if any, existing knowledge on which older adults can base their learning. This paper investigates a custom file management interface that was designed to aid discovery and learnability by providing interface objects that are familiar to the user. A study was conducted which examined the differences between older and younger computer users when undertaking routine file management tasks using the standard Windows desktop as compared with the custom interface. Results showed that older adult computer users requested help more than ten times as often as younger users when using a standard windows/mouse configuration, made more mistakes and also required significantly more confirmations than younger users. The custom interface showed improvements over standard Windows/mouse, with fewer confirmations and less help being required. Hence, there is potential for an interface that closely mimics the real world to improve computer accessibility for older adults, aiding self-discovery and learnability.

References

  1. Shari Trewin, Bonnie E. John, John Richards, Cal Swart, Jonathan Brezin and John Thomas (2010). Towards a Tool for Keystroke Level Modeling of Skilled Screen Reading Proceedings of the 12th International ACM SIGACCESS Conference on Computers and Accessibility, 1 (1)
  2. Nic Hollinworth and Faustina Hwang (2010). Relating Computer Tasks to Existing Knowledge to Improve Accessibility for Older Adults Proceedings of the 12th International ACM SIGACCESS Conference on Computers and Accessibility, 1 (1)