The image below shows a screenshot of Retrospector (one pet-project of mine) visualizing the activity on my machine between 15 september and 15 october.

Principles behind the picture construction:
- Days are arranged sequentially as rows along the y-axis
- Time flows along the x-axis and vertical lines corresponding to hours are visible for guidance. There is a bold line at 8 o’clock.
- Every application has an associated color
- Continuous usage of a given application during a day is represented as a horizontal bar having the color of the application

The picture tells several things about me:

• I don’t have a nine-to-five job :)
• The long and sometimes late programming sessions (green) and frequent writing sessions (magenta) give away the fact that a deadline was approaching :)

Some things for which such a tool might be useful are:

• Learning about oneself: one could see when are his best periods for certain activities. The images shows that I have some great programming sessions when the majority of the people in my town are sleeping :)
• Learning about how different people work: by analyzing how the activities of various users look one might derive user types and habits (if you are a mac user and want to contribute by observing yourself please let me know :)

On one hand, I think this is a cool project. On the other hand, there is always a privacy issue. How much is one willing to make public about his activities? Would people agree to send their activity data for analysis by a psichologist or for data mining? Maybe if I found a way to anonymize the data? Wouldn’t this type of display lead to supperficial characterizations of people?