Document Type


Date of Degree

Summer 2012

Degree Name

PhD (Doctor of Philosophy)

Degree In

Computer Science

First Advisor

Hourcade, Juan Pablo

First Committee Member

Segre, Alberto

Second Committee Member

Stump, Aaron

Third Committee Member

Bruell, Steve

Fourth Committee Member

Samuelson, Larissa


Four studies describe the pointing performance of individuals with fine motor skills impairments. First, we describe the pointing performance of two individuals with Parkinsons disease via a sub-movement analysis and compare them with similar results found in the literature from young children and older able-bodied adults. The analysis suggests the need of an individual assessment of pointing difficulties and the personalization of the methods of assistance and motivates sub-sequent studies. Two experiments followed where we tested PointAssist, software that assists in pointing tasks by detecting difficulty through a sub-movement analysis and triggering help, with adjustments proposed to personalize the assistance provided. A within-subjects study with sixteen individuals with fine motor skills impairments resulted in statistically significant effects on accuracy using Friedman's test with (χχ/sup>(1) = 6.4, p = .011) in favor of personalized PointAssist. A five week longitudinal study with three participants with Cerebral Palsy and other fine motor skills impairments shows the long term effects of PointAssist. The longitudinal study logged real-world use of pointing devices validating the results for real-world interactions. PointAssist had statistically significant effect of reduced sub-movement length and speed with p < .00001 and p < .0002 respectively for one of the participants. These results suggest better motor control near a target and statistically significant results on the sub-movement duration confirmed this. Finally, we designed, developed and tested a new assistive technology for individuals with severe motor skills impairments that we call the Reverse Funnel. Three participants, two with Cerebral Palsy and one with an undisclosed disability, participated and positive early results are presented as well as future developments of the newly developed strategy.


Assistive Technologies, Human Computer Interaction, Motor Impairments, Pointing, Submovements


xxii, 203 pages


Includes bibliographical references (pages 198-203).


This thesis has been optimized for improved web viewing. If you require the original version, contact the University Archives at the University of Iowa:


Copyright © 2012 Guarionex Jordan Salivia