Recent work by Mandryk and Lough demonstrated that the movement time of Fitts-style pointing tasks varies based on intended use of a target, suggesting major implications for HCI research that models pointing using Fitts' Law. We replicate the study of Mandryk and Lough to determine exactly how and why observed movement times vary. We demonstrate that any variation in movement time is the result of differences in additive factors (a in Fitts' equation) and can be attributed to changes in the time a user spends over their primary target.

Jaime Ruiz and Edward Lank. 2014. Analyzing intended use effects in target acquisition. In Proceedings of the 2014 International Working Conference on Advanced Visual Interfaces (AVI '14). ACM, New York, NY, USA, 145-152.

@inproceedings{Ruiz:2014:AIU:2598153.2598158,
 author = {Ruiz, Jaime and Lank, Edward},
 title = {Analyzing Intended Use Effects in Target Acquisition},
 booktitle = {Proceedings of the 2014 International Working Conference on Advanced Visual Interfaces},
 series = {AVI '14},
 year = {2014},
 isbn = {978-1-4503-2775-6},
 location = {Como, Italy},
 pages = {145--152},
 numpages = {8},
 url = {http://doi.acm.org/10.1145/2598153.2598158},
 doi = {10.1145/2598153.2598158},
 acmid = {2598158},
 publisher = {ACM},
 address = {New York, NY, USA},
 keywords = {Fitts' law, intention, motion kinematics, pointing},
}