Fitting Motivation to Fitts’ Law : Effect of a Penalty Contingency on Controlled Movement

2018 ◽  
Vol 62 (1) ◽  
pp. 265-269 ◽  
Author(s):  
Douglas J. Gillan ◽  
Randolph G. Bias
Keyword(s):  
Movement Time ◽  
Movement Control ◽  
Target Size ◽  
Movement Behavior ◽  
Target Acquisition ◽  
Computer Screen ◽  
Fitts Law ◽  
Starting Point ◽  
Movement Distance ◽  
Index Of Difficulty

An experiment examined the effect of a penalty on performance of target acquisition movements, focusing on overall movement time, the fit of the data to Fitts’ Law, and ballistic and homing submovements. Fitts’ Law, MT = a + b[Index of Difficulty], where Index of Difficulty (ID) = log2[Movement distance/target size], focuses on the control of the movement by external stimuli, rather than the consequences of a movement. In this study, participants moved a cursor on a computer screen from a starting point to a target with movement distance and target size varying systematically. In the Penalty condition, when the movement missed the target, the computer screen went blank and the next trial was delayed for 30 seconds. In the Nonpenalty condition, participants did not receive a penalty for missing the target. The results showed that receiving a penalty led to higher movement times, a higher Fitts’ Law slope parameter, fewer errors, and fewer nonerror overshoots of the target. Also, receiving penalties resulted in target acquisition movements with less time spent in the ballistic submovement. The results show that consequences of a movement control movement behavior.

Visual Control of Discrete Aiming Movements

1983 ◽  
Vol 35 (2) ◽  
pp. 311-321 ◽  
Author(s):  
Stephen A. Wallace ◽  
Karl M. Newell
Keyword(s):  
Error Rate ◽  
Movement Time ◽  
Visual Control ◽  
Correction Model ◽  
Fitts Law ◽  
Rate Analysis ◽  
Movement Distance ◽  
Rapid Arm Movements ◽  
Index Of Difficulty ◽  
Highly Correlated

An experiment is reported which investigated the visual control of discrete rapid arm movements. Subjects were required to move as rapidly as possible to several target width-movement distance combinations under both visual and non-visual conditions. The movement time (MT) data were supportive of Fitts' Law in that MT was linearly related and highly correlated to the Index of Difficulty (ID). MT was also similar for different target width-distance combinations sharing the same ID value. The error rate analysis, which compared visual to non-visual Performance, indicated that vision was only used, and to varying degrees, when MT exceeded 200 ms (3.58 ID level). There was some evidence that vision was differentially used within target width-distance combinations sharing the same ID. Estimates of endpoint variability generally reflected the results of the error rate analysis. These results do not support the discrete correction model of Fitts' Law proposed by Keele (1968).

scholarly journals Both Sides Now: Both Height and Width of the Target Matter for Applying Fitts’ Law to Pointing Using a Mouse

2019 ◽  
Vol 63 (1) ◽  
pp. 381-385
Author(s):  
Douglas J. Gillan
Keyword(s):  
User Interface ◽  
Interface Design ◽  
Movement Time ◽  
User Interface Design ◽  
Task Environment ◽  
Target Height ◽  
Fitts Law ◽  
Starting Point ◽  
Direction Of Movement ◽  
Index Of Difficulty

Research on target acquisition has focused on two features of the task environment – the distance moved and the size of the target in the direction of movement. The present research examined the effect of the size of the target in the direction orthogonal to the direction of movement (typically called the target height) on the time to move to a target. The experiment varied the Index of Difficulty (ID) (by varying the distance moved and the target width) and the target height in a task in which participants moved a cursor from a starting point to the target. The results found that (1) movement time was linearly related to ID at each of three levels of target height, (2) movement time increased as target height decreased, and (3) the slope of the function relating movement time to ID decreased as target height decreased. The discussion addresses two possible explanations for the results, how Fitts’ Law might be modified to take target height into account, and how the results could be applied to user interface design.

Factors Affecting Remote Positioning Performance

1995 ◽  
Vol 39 (4) ◽  
pp. 282-286
Author(s):  
Shang H. Hsu ◽  
Chien C. Huang
Keyword(s):  
Movement Time ◽  
Interactive Effect ◽  
Vertical Movement ◽  
Movement Direction ◽  
Movement Amplitude ◽  
Distance Ratio ◽  
Factors Affecting ◽  
Fitts Law ◽  
Movement Distance ◽  
Two Measures

The purpose of this study was to investigate the effects of target width, movement direction, movement amplitude, and remote distance on remote positioning performance. Movement time and movement distance ratio were taken as measures of remote positioning performance. It was found that the effects of target width, movement amplitude, and movement direction on the two measures were significant. The effect of remote distance was significant only for movement distance ratio. The magnitude of the effect of target width on movement time was larger than that of movement amplitude; a modification of Fitts' Law was thus proposed. Moreover, there was an interactive effect between target width and movement direction- i.e., movement direction had an effect only when the target width was small. Among the eight movement directions, upward vertical movement was the best for remote positioning. The results shed some light onto the design of remote control user interface.

Effects of Gain and Index of Difficulty on Mouse Movement Time and Fitts’ Law

2019 ◽  
Vol 49 (6) ◽  
pp. 684-691
Author(s):  
Yik Hang Pang ◽  
Errol R. Hoffmann ◽  
Ravindra S. Goonetilleke
Keyword(s):  
Movement Time ◽  
Fitts Law ◽  
Mouse Movement ◽  
Index Of Difficulty

Effects of Smoking Abstinence on Movement Regulation

2000 ◽  
Vol 90 (2) ◽  
pp. 624-630 ◽  
Author(s):  
Thomas S. Marzilli ◽  
John B. Shea
Keyword(s):  
Information Processing ◽  
Psychomotor Performance ◽  
Movement Time ◽  
Smoking Abstinence ◽  
Fitts Law ◽  
Single Plate ◽  
Index Of Difficulty ◽  
Psychomotor Tasks ◽  
Nicotine Deprivation ◽  
Minimal Information

The effect of smoking abstinence on performance of a reciprocal tapping task was investigated. 6 habitual smokers performed a single-plate and two versions of a two-plate tapping task. Fitts' Law was used to compute an index of difficulty (ID) in bits for the tasks which was 0 bits for the single-plate and 3.32 and 4.17 bits for the two-plate versions of the task. While smoking abstinence had no effect on performance of the single-plate tapping task, it increased movement time on performance of both two-plate task versions. These findings may provide a coherent explanation for the prior findings of nicotine deprivation on psychomotor performance in the literature. This explanation suggests that the effects of nicotine deprivation as incurred through smoking abstinence may be on the central mechanisms regulating information-processing rate for successful movement regulation. Thus nicotine deprivation may not affect performance of simple psychomotor tasks which require minimal information processing but will affect the performance of more complex tasks requiring significantly more information processing for successful movement regulation.

Movement Control and Maturation in Elementary-Grade Children

1975 ◽  
Vol 41 (1) ◽  
pp. 151-154 ◽  
Author(s):  
Robert Kerr
Keyword(s):  
Significant Relationship ◽  
Movement Time ◽  
Motor Task ◽  
Movement Control ◽  
Arm Movement ◽  
Skeletal Age ◽  
Fine Motor ◽  
X Rays ◽  
Fitts Law ◽  
Elementary Grade

Serial tapping by 5-, 7- and 9-yr.-old boys and girls, as measured by Fitts' Law, was recorded. 60 Ss performed a reciprocal tapping task and were assessed developmentally via hand-wrist X-rays. No significant relationship was found between the fine motor task and skeletal age. The results of the motor task suggest an improvement in movement time, with age, due to an ability to plan subsequent movements rather than simply an increase in speed of arm movement.

Improving on Human’s Movement Time Model for Pointing Task - Introducing the Target Position Factor into Fitts’ Law

2012 ◽  
Vol 433-440 ◽  
pp. 2349-2355
Author(s):  
Jun Min Du ◽  
Hai Wen Shi
Keyword(s):  
Movement Time ◽  
Target Position ◽  
Model Fit ◽  
Time Data ◽  
Conventional Model ◽  
Time Model ◽  
Fitts Law ◽  
Pointing Movement ◽  
Starting Point ◽  
Pointing Movements

The experiments were aimed at determining the effect of target position on movement time when performing a target pointing movement task. 21 subjects performed pointing movements with 72 conditions of various target position. The movement time data were collected. It was shown that the starting point position and target position greatly affect the movement time. As a result, the movement times were not explained satisfactorily by the conventional Fitts’ model. The conventional model was improved by introducing the target position factor into. Compared with the conventional Fitts’ model, the new model could describe the data better, both in term of contribution value (r2) and the standard error of the residual between the predicted value by model fit and the measured movement time.

Three-Dimensional Movement Trajectories in Fitts' Task: Implications for Control

1987 ◽  
Vol 39 (4) ◽  
pp. 629-647 ◽  
Author(s):  
C. L. MacKenzie ◽  
R. G. Marteniuk ◽  
C. Dugas ◽  
D. Liske ◽  
B. Eickmeier
Keyword(s):  
Movement Time ◽  
Three Dimensional ◽  
Velocity Profiles ◽  
Target Size ◽  
Movement Amplitude ◽  
Aiming Movements ◽  
Movement Trajectories ◽  
Resultant Velocity ◽  
Family Of Curves ◽  
Index Of Difficulty

According to Fitts (1954), movement time (MT) is a function of the combined effects of movement amplitude and target width (index of difficulty). Aiming movements with the same index of difficulty and MT may have different planning and control processes depending on the specific combination of movement amplitude and target size. Trajectories were evaluated for a broad range of amplitudes and target sizes. A three-dimensional motion recording system (WATSMART) monitored the position of a stylus during aiming movements. MT results replicated Fitts’ Law. Analysis of the resultant velocity profiles indicated the following significant effects: As amplitude of movement increased, so did the time to peak resultant velocity; peak resultant velocity increased slightly with target size, and to a greater extent with increases in the amplitude of movement; the time after peak resultant velocity was a function of both amplitude and target size. Resultant velocity profiles were normalized in the time domain to look for scalar relation in the trajectory shape. This revealed that: the resultant velocity profiles were not symmetrical; the proportion of time spent prior to and after peak speed was sensitive to target size only, i.e. as target size decreased, the profiles became more skewed to the right, indicating a longer decelerative phase; for a given target size, a family of curves might be defined and scaled on movement amplitude. These results suggest that a generalized program (base trajectory representation) exists for a given target width and is parameterized or scaled according to the amplitude of movement.

scholarly journals A New Approach to Modeling the Prediction of Movement Time

Mathematics ◽  
2021 ◽  
Vol 9 (14) ◽  
pp. 1585
Author(s):  
Chiuhsiang Joe Lin ◽  
Chih-Feng Cheng
Keyword(s):  
Movement Time ◽  
Human Movement ◽  
Average Amount Of Information ◽  
Movement Response ◽  
New Approach ◽  
Fitts Law ◽  
Proposed Model ◽  
Index Of Difficulty ◽  
Human Movement Response ◽  
Better Than

Fitts’ law predicts the human movement response time for a specific task through a simple linear formulation, in which the intercept and the slope are estimated from the task’s empirical data. This research was motivated by our pilot study, which found that the linear regression’s essential assumptions are not satisfied in the literature. Furthermore, the keystone hypothesis in Fitts’ law, namely that the movement time per response will be directly proportional to the minimum average amount of information per response demanded by the particular amplitude and target width, has never been formally tested. Therefore, in this study we developed an optional formulation by combining the findings from the fields of psychology, physics, and physiology to fulfill the statistical assumptions. An experiment was designed to test the hypothesis in Fitts’ law and to validate the proposed model. To conclude, our results indicated that movement time could be related to the index of difficulty at the same amplitude. The optional formulation accompanies the index of difficulty in Shannon form and performs the prediction better than the traditional model. Finally, a new approach to modeling movement time prediction was deduced from our research results.

Comparison of Six Cursor Control Devices Based on Fitts' Law Models

1986 ◽  
Vol 30 (4) ◽  
pp. 327-331 ◽  
Author(s):  
Brian W. Epps
Keyword(s):  
Regression Analysis ◽  
Movement Time ◽  
Performance Data ◽  
Target Acquisition ◽  
Acquisition Performance ◽  
Cursor Control ◽  
Fitts Law ◽  
Acquisition Task ◽  
Control Devices ◽  
Best Fit

Six cursor control devices were compared on a target acquisition task which required subjects to move a cursor into square targets of varying sizes and at various screen distances. The target acquisition performance data were fitted to movement time models proposed by Fitts, Jagacinski, and Kvalseth. Regression analysis results indicated good predictions of target acquisition performance for the six cursor devices. The best fit was obtained with the trackball across the three models.

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