Fittslaw for pointing visual range for motion, shape, colour, detail and their consequences for design decisions visual attention models alternative sensory channels. Fitts law as a research and design tool in humancomputer. A central thesis in fitts work is that throughput is independent of movement amplitude and target width, as embedded in id. According to fitts law, human movement can be modeled by analogy to the transmission. However, fitts law does not always prove to be an accurate descriptor of movement or task performance time in all cases gan and hoffman, 1988. Movement time prediction methods were developed by paul fitts as a part of a long history in the examination of the issue of speed vs. A literature survey on fitts law and its applications. Laws of movement learning and control iresearchnet. Steering law steering law accot and zhai 1997 eyond fitts law. In other words, as id changes due to changes in a or w, mt changes in an opposing manner and tp remains more. June 2224, 2014 you may be coming in cold from engineering, graphic design, psychology, or beyond.
Fittss law for the timing of targeted movements states that, when target width is held constant, movement time mt will increase as the travelled distance increases. A simple fitts law equivalent for combined movements with a similar. Fitts law is the most successful quantitative law used in hci 21, 26 and has proved extremely robust across a wide range of conditions. The theory behind fitts wellknown pointing law, commonly used in humancomputer interaction. Fitts law 3 is the standard empirical tool for assessing and comparing the efficiency of pointing techniques. A literature survey on fitts law and its applications runa barik, sujeet kumar abstract the way of pointing a target object and the movement time of the pointer lead to a challanging problem in hci. This site uses cookies for analytics, personalized content and ads. Fitts law has been an integral method that has been used when designing computer technology since. This suggests that the person can trade off a little speed for a gain in accuracy. Fittss law often cited as fitts law is a model of human movement in humancomputer interaction and ergonomics which predicts that the time required to rapidly move to a target area is a function of the distance to and the size of the target.
According to fitts law, the time to move and point to a target of width. Like all great demos, os x has been stripped of all those extraneous details that detract from initial reaction, extraneous details like the names of the files you are working on. We tested whether fitts law applies under various conditions of visual restriction and. Learn vocabulary, terms, and more with flashcards, games, and other study tools.
Fortunately, readers of asktog, being as tenacious as they are perspicacious, either know exactly what fitts law is or will before they go to bed tonight. Leganchuk, zhai and buxton 1999 have also verified the manual. Fittss law is used to model the act of pointing, either by physically touching an object. On the validity of using firstperson shooters for fitts. Fittss law often cited as fitts law is a model of human movement in. By continuing to browse this site, you agree to this use. Human have processing constraints motor limitations, e. In the realm of human movement, fitts law is the preeminent model. Assessment of fitts law for quantifying combined rotational. The objective of this study is to gather data about the speed with which humans move to targets of different sizes and at different. Build a firm foundation in interaction design with this three day course.
Fitts law as a research and design tool in humancomputer interaction. Im going to start by giving you an examplefrom webbased email clients. Fitts law indicates that if the errors are too large, the performer must slow down to reduce them. Movement time prediction in humancomputer interfaces.
Bruce tognazzini in his asktog uses the form fitts law despite saying it should be spelled fitts s by his interpretation of the rules of american english. Fitts law does not apply to saccadic eye movements. Although targets a and b have the same size, the distance from cursor to a d1 is shorter than the distance to b d2, so movement to a will be faster. Fitts law robustly predicts the time required to move rapidly to a target. Even imagined movements, mentally simulated actions without actual actions, obey fittss law. Fitts law, a fundamental principle of interaction design, from asktog, the webzine for computer professionals, their family, and friends. The original formulation of fitts law as applied to user interface design by. Motor learning final exam 5,6,7 ans 7,8,9, flashcards. Recent evidence has emerged that aiming to a target located last in an array of placeholders results in a shorter movement time than would be expected by the fitts equationa violation of fitts law. Also, some recent work in modelling users pointing performance.
Fitts law holds for pointing movements under conditions. Usually, though, it is merely a leading indicator of overall ignorance, amplified by superstition and unsullied by facts or study. Bruce tognazzini in his asktog uses the form fitts law despite saying it should be spelled fittss by his interpretation of the rules of american english. In humancomputer interaction and ergonomics, fittss law often cited as fitts law is a model of human movement which predicts the time required to rapidly move to a target area, as a function of the distance to the target and the size of the target fittss law is used to model the act of pointing, both in the real world e. Movement time prediction in humancomputer interfaces i. The personal information to be collected in the study will not be linkable to individual participants in the study.
One of those constraints is how the designof something makes it easier or harder to click on. Both statements are in accordance with common sense. These laws are of interest to sport and exercise psychologists because they specify relatively simple. Fittss law is expressed mathematically by the following formula. Fittss law often cited as fitts law is a predictive model of human movement primarily used in humancomputer interaction and ergonomics. Fittsbits a game investigating fitts law by willem vervuurt and laura cuijpers this game, a webbased experiment, is no longer available fitts law at asktog. Fitts law says that the time to reach target a is shorter than the time to reach any of the other targets.
Fitts law is an effective quantitative method of modeling user performance in rapid, aimed movements, where one appendage like a hand starts at rest at a speci. However, it is unclear whether fitts law holds for visually guided actions under visually restricted conditions. While at first glance, this law might seem patently obvious, it is one of the most ignored principles in design. Fittss law the glossary of human computer interaction. Cognitive theories in hci school of information sites. Eeg correlates of fittss law during preparation for action. Models and theories in humancomputer interactionthe. Fitts law holds that, to maintain accuracy, movement times of aiming movements must change as a result of varying degrees of movement difficulty. Fitts laws degradation in small target acquisition tasks and particularly so when the implement of the acquisition is a fat finger.
Fittss law is used to model the act of pointing, either by physically touching an object with a hand or finger, or virtually, by pointing to an. Fitts law states that it takes more time to hit a target if the target is further away and it also takes more time if the target is smaller. In this entry, the focus is on three of the most firmly established of these laws. Understanding this law helps us design better buttons, forms, lists, and other interactive elements. The critical variable is the id, which depends on the amplitude a of the movement i. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. I previously mentioned 8pen in a positive manner, an. Fitts law has been successfully applied to translational. Various laws of movement learning and control have been proposed on the basis of research. Pdf creating fitts law predictions for a touchscreen. Article pdf available in experimental brain research 20. Fitts law is a powerful model of human movements that predicts the time that it takes to. Fitts s l aw describes how long it takes a user to hit a target in a graphical user interface gui or other design, as a function of size and distance. Fittss law can accurately predict the time it will take a person to.
Fitts law is a model of human psychomotor behavior developed in 1954 6. And i think he forgot about the simplicity of the compound noun form. The key statement of fittss law is that the time required to move a pointing device to a target is a function of the distance to the target and its size. Even though theyre digital rather than physical,there are still some physical constraintswe need to bear in mind. An experimental study, and applications to user interface design michael john mcgu n master of science graduate department of computer science university of toronto 2002 there exist several user interface widgets that grow or. This scientific law predicts that the time required to rapidly move to a target area is a function of the ratio between the distance to the target and the width of the target. Modeling finger touch with fitts law dualdistribution hypothesis. In safari, it took me two years to learn the rule for printing a pdf document. Human information processing klm, goms, fitts, hicks.
Moreover, the hci community uses few formulas, and are related to fitts law. A large number of seminal paper have been proposed towards this. This little bit of obviousness is so often ignored, i sometimes wonder if it is on purpose. When we create interfaces,were making a set of controlsfor people to interact with. The underlying mechanism of such deviation from fittss law seems to be rooted in the motor system in the way it. Fitts law often cited as fittss law is a model of human movement primarily used in humancomputer interaction and ergonomics that predicts that the time required to rapidly move to a target area is a function of the distance to the target and the size of the target. When labels are not used, the tool icons crowd together tool matrix example you have a palette of tools in a graphics application that consists of a matrix of 16x16pixel icons laid out as a 2x8 array that lies along the lefthand edge of the screen. The time to acquire a target is a function of the distance to and size of the target.
Fittss original equation describing the relation between amplitude, accuracy, and duration of hand movements, the duration depends on the logarithm of the ratio of amplitude and accuracy. While i applaud the designers for what they have done to datemuch of which. The program is called quikfitt, which is designed to demonstrate and teach the computer science theory of fitts law to people without a background in computer science and to present it in such a manner that people see it as genuine science. Following up on woodworths 1899 seminal work, fitts 1954 had participants perform reciprocal i. Stuart card, alan mewell, and tom moran used fitts law to test various humancomputer interaction devices while working at the palo alto research center, and from these studies, it came forward that the mouse was the best way. It has been extended, among other things, to 2d pointing 22, 10, 11, 3d pointing 9 and multiscale navigation 12. Fitts law properly spelled fitts s, per the rules of american english, though rarely done so is simple, absolute, and immutable. Fittss law often cited as fitts law is a descriptive model of human movement primarily used in humancomputer interaction and ergonomics. The most common formulation of fitts law comes from 30 and is referred to as the \shannon formulation. Fitts robust model shows that the time to select an item is proportional to the logarithm of the distance to the target divided by the target size. The solution is named 8pen, illustrating that the most natural finger gesture on a touch panel is circling, and drawing continuous 8s on the screen. Fitts law 14 is a classic and wellstudied law, which quanti es pointing actions in terms of the size, distance, and time to reach the target.
Start studying motor learning final exam 5,6,7 ans 7,8,9. Fitts law also states that the target acquisition time increases drastically if the target gets tiny. My previous discussion regarding the limitation of fitts law on mobile device introduced an attempt to solve the motionbehavioral problem, a finger gesturebased keyboard design. Today, with the advent of graphical user interfaces and different styles of interaction, fitts law seems to have more importance than ever before. Fittss law is used to model the act of pointing, either by physically. This is easy to understand, not too difficult to implement and it doesnt seem to make much sense to contradict such a simple and obvious. The generality of fittss law lisanne bainbridge 1 and moira sanders university of reading, reading, england ju p. Fitts law in essence reveals a speedaccuracy tradeoff rule in human control performance.
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