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Qualitative Results

Déjà Vu is easier than it looks: Although some users remarked that they would never be able to remember the portfolios they created, all were surprised that they could recognize their images and at how quickly the selection took place. It is interesting to note that after the first week, more users forgot their usernames than their portfolios.

Text vs. images: The majority of users reported that photo portfolios were easier to remember than PINs and passwords, especially after 1 week, and that they would use such a system if they were confident that it was secure and if image selection times were improved.

Random Art vs. photos: Users varied in whether they thought photo or Random Art portfolios were easier to use.

Users tend to select photographic images based on a theme or something that has personal meaning to them. (e.g., hobbies, places they have visited). There was much more variation in the Random Art images selected by users compared to the photographs. For example, although participants were presented with a choice of 100 images, 9 out of the 20 participants included a photograph of the Golden Gate bridge in their portfolios. In contrast, there were few Random Art images that were chosen by more than one user.

After the user testing was complete, users described the portfolios they had chosen. The descriptions of a photograph chosen by more than one user were virtually identical from user to user. However, no two descriptions of a Random Art image were alike. Participants found it hard to describe or to recall the Random Art images in concrete terms and instead related them to objects or actions (e.g., ``it looks like a woman dancing''). For this reason, we conjecture that it would be hard for a third party to identify another's portfolio images based on descriptions or recalled drawings alone. Further study is needed to see if this is the case.

next up previous
Next: Interface Issues Up: User Study Previous: Task Completion Time and

Adrian Perrig
Thu Jun 15 15:16:10 PDT 2000