Paper Reading #1 - Only One Fitts’ Law Formula – Please!

Comments:
Comment 1
Comment 2

Reference:
Title: Only One Fitts’ Law Formula – Please!
Author: Heiko Drewes
Venue: CHI EA 2010, April 10-15, 2010

Summary:
In this paper, Heiko Drewes describes the current state of Fitts' Law in HCI and how it conflicts with the scientific principles on which he believes the field of HCI is supposed to stand.

Fitts' Law gives a basic formula for the average time it takes for a human to hit a target of a certain size at a certain distance. The picture to the left, taken from the original document, shows the basic idea of the formula: the time it takes to move from the start position to a smaller circle around the target is measured, and then repeated for a smaller circle until the target is reached. By adding these times together, a formula is created that allows the average time to be calculated.





Over the years, four main versions of the same formula for this law have been proposed, and all of them have been used in variation. The author makes the point that allowing four formulas on the same principle to all be called correct and be used in this manner violates scientific principles. Additionally, the author indicates a problem with the way the formula is used to check experimental data.

Finally, the author makes a case for the correctness of the original formula, and asks for members of the HCI community to come together to standardize a formula for Fitts' Law.

Discussion:
This article is interesting because it discusses a current schism in the HCI community, while also making a statement about the field at large. By indicating an inability to stick to a single formula, as in other sciences, he quickly makes a case for standardization. However, by being so frank about the HCI community as a whole, he seems to me to be almost insulting to the community as a whole.

The main possibilities of extending this work would be running a large study to determine the true correctness of these four varying formulas for Fitts' Law, or to get a committee together to decide which one to choose.