Sunday, August 24, 2008

GaCIT in Tampere, day 5.

On Friday, the last day of GaCIT, Ed Cutrell from Microsoft Research gave a talk concerning usability evaluation and how eye tracking can give a deliver a deeper understanding. While it has been somewhat abused to convince the managment with pretty pictures of heat maps it adds value to a design inquiry as an additional source of behavioral evidence. Careful consideration of the experiment design is needed. Sometimes studies in the lab lacks the ecological validity of the real in-the-field research, more on this further on.

The ability to manipulate independent variables, enforce consistency and control are important concerns. For example running a web site test against the site online may produce faulty data since the content of the site may change for each visit. This is referred to as the stimuli sensitivity and increses in-between power since all subjects are exposed to exactly the same stimuli. Another issue is the task sensitivity. The task must reflect what the results are supposed to illustrate (ie. reading a text does not contain elements of manipulation. People are in general very task oriented, instructed to read they will ignore certain elements (eg. banners etc.)

A couple of real world examples including the Fluent UI (Office 2008), Phlat and Search Engine Results Pages (SERP) were introduced.

The Fluent UI is the new interface used in Office 2008. It resembles a big change compared with the traditional Office interface. The Fluent UI is task and context dependent compared to the rather static traditional setup of menubars and icons cluttering the screen.

Example of the Fluent UI (Microsoft, 2008)

The use of eye trackers illustrated how users interacted with the interface. This may not always occur in the manner the designer intended. Visualization of eye movement gives developers and designers a lot of instant aha-experiences.

At Microsoft it is common to work around personas in multiple categories. These are abstract representations of user groups that help to illustrate the lifes and needs for "typical" users. For example, Nicolas, is a tech-savvy IT professional while Jennifer is a young hip girl who spend a lot of time on YouTube or hang around town with her shiny iPod (err.. Zune that is)

More information on the use of personas as a design method:
  • J. Grudin, J. Pruitt (2002) Personas, Participatory Design and Product Development: An Infrastructure for Engagement (Microsoft Research) Download as Word doc.

  • J. Grudin (2006) Why Personas Work: The Psychological Evidence (Microsoft Research) Download as Word doc.
Moving on, the Phlat projects aims at solving the issues surrounding navigating and searching large amounts of personal data, sometimes up to 50GB of data. Eye trackers were used to evaluate the users behavior agains the interface. Since the information managed using the application is personal there were several privacy issues. To copy all the information onto the computers in the lab was not a feasible solution. Instead the participants used the Remote Desktop functionality which allowed the lab computers to be hooked up with the participants personal computers. The eye trackers then recorded the local monitor which displayed the remote computer screen. This gives much higher ecological validity since the information used has personal/affective meaning.

Phlat - interface for personal information navigation and search (Microsoft)
The use of eye trackers for evaluating websites has been performed in several projects. Such as J. Nielsens F-Shaped Pattern For Reading Web Content and Enquiros Search Engine Results (Golden Triangle). Ed Cutrell decided to investigate how search engine results pages are viewed and what strategies users had. The results gave some interesting insight in how the decision making process goes and which links are see vs clicked. Much of the remaining part of the talk was concerned with the design, execution and results of the study, great stuff!

Further reading:
Unfortunately I had to catch a flight back home in the afternoon so I missed Howell Istance last talk. However, I´ll get a new opportunity to hear one of his excellent presentation in a weeks time at COGAIN2008.

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