7 ms·
Fitt's Law
- longwave 11y agoCorrect title is "Fitts's law" as it is named after Paul Fitts.
- VeejayRampay 11y agoIt'd be Fitts' Law then, wouldn't it?
- extra88 11y agoThe apostrophe comes at the very end only when the s has been added to a word to make it plural. You don't add an s to make a word plural and another s to make it possessive. If you write about the wealth of Donald Trump, it's "Trump's money" but the wealth of the Trump family (i.e. multiple people) it's "Trumps' money." There is no singular "Fitt" so Fitts's Law is correct, same as "Laura Poitras's films." The apostrophe also comes at the very end when "es" is added to make a word plural, e.g. "fishes' spawning ground."
- VeejayRampay 11y agoThanks for the explanation. As an ESL English speaker, this has a tendency to get me confused.
- oneeyedpigeon 11y agoEither is valid; "Fitt's" is absolutely wrong, though.
- deleted 11y ago[deleted]
- mavhc 11y agoThere's no rules, but for me it depends how you pronounce it, if you say Fitts then it's Fitts', if you say Fitts-es it's Fitts's
- stevetrewick 11y agoWas about to post 'there are so rules!' because my SO's design students often claim this is true of apostrophe use in general resulting in much gnashing of teeth, but I checked and stone me if you aren't right in this particular case. Rules 1b and 1c http://m.grammarbook.com/punctuation-rules/apostrophes.aspx http://m.grammarbook.com/punctuation-rules/apostrophes.aspx
- TuringTest 11y agoAnyone interested in Fitts's law should also know about Accot-Zhai steering law. [1] [1] https://en.wikipedia.org/w/index.php?title=Accot-Zhai_steering_law https://en.wikipedia.org/w/index.php?title=Accot-Zhai_steeri...
- oneeyedpigeon 11y agoWhilst maybe not strictly accurate, I've always strongly associated Fitt's Law with two things that OSX gets tragically wrong. I really cannot fathom why these bugs (they are, undoubtedly bugs, unless anyone can argue otherwise) persist. 1. Menu items. Pull down the main menu on OSX, and find a menu with a separator - a line between groups of related actions. The separator itself isn't a target - it doesn't lead anywhere - but clicking it dismisses the menu. So, miss your intended target by a few pixels, and frustration ensues. 2. Window edges. This one is a side-effect of OSX's poor support for full-screen windows. Even if you 'maximise' a window, moving your pointer to an extreme edge does, for example, allow you to move the scrollbar, but persists in offering the 'size window' action. So you need to go all the way to one edge, then move ever so slightly back again, which reduces the target area from infinite to very small. Full-screen addresses this, whilst introducing other 'flaws' (like your global menubar no longer being visible).
- kisstheblade 11y agoAlso the corners at the bottom do nothing. I never understood why the dock just floats stupidly in the middle, rendering stuff to the left and right of it unusable for anything, especialy the corners of the screen. Form over function, I guess.
- oneeyedpigeon 11y agoYes, the dock is terrible - I autohide it to avoid problems. Newer versions (I'm still on 10.9) use a more two-dimensional dock which would be well suited to 'framing' the main window area, at full-width, much as the global menubar does. Then I'd be able to have my ideal setup - dock permanently visible (but probably quite short), and ability to have windows fully maximised, in-between the global menubar and the dock.
- prawn 11y agoThe corners can be used as hotspots however. For example, bottom right to lock the screen. Not brilliant but not without function. The dock is terrible. I edited a config file to have mine as small as possible and then auto-hide it. Also never use Mission Control or whatever the launcher grid screen is called. Spotlight set only to show apps and client directories does everything I need.
- simula67 11y agoMuch better explanation for CS people here : https://www.youtube.com/watch?v=E3gS9tjACwU https://www.youtube.com/watch?v=E3gS9tjACwU This is why I gave up my second monitor.
- dandare 11y agoThanks, for a minute I thought I am stupid for not understanding the Wikipedia definition :)
- dudifordMann 11y agoI donot understand your point. As a SW engineer who focuses on UI design and implementation, my desk has three screens. One screen dedicated to execution, one dedicated to code, and one dedicated to spreadsheets or design documents, etc. My Fitts's law analysis happens on a target platform and not my development system. Could you elaborate?
- simula67 11y agoThe problem with multiple monitors is that it becomes harder to acquire UI elements placed at the corners. Like for example the "Close" button, "Start" button, "Show Desktop" button, scroll bars etc.
- evanmoran 11y agoFor me, this is what shortcuts are for. The start button on my keyboard is faster than mouse targeting.
- makecheck 11y agoI remember how long it took Microsoft to get this right. The first few versions of the Start menu and task bar items had a couple of pixels of space separating them from the edge of the screen. It was like snatching defeat from the jaws of victory, such a profound reduction in usability over what was probably someone’s arbitrary aesthetic choice.
- jdeisenberg 11y agoAn old, but good article: http://www.asktog.com/columns/022DesignedToGiveFitts.html http://www.asktog.com/columns/022DesignedToGiveFitts.html
- uxcn 11y agoFItts' Law partly explains why I prefer keyboard oriented interfaces.
- dbcurtis 11y agoMy friends and I have a word for violations of Fitts' law. We call it "pixel spearing". It is incredibly frustrating to have to spear exactly the right pixel in order to get something done on the GUI. The original Mac had this right. Gnome used to get this right. What is it with GUI designers that they think pixel spearing is OK? It's like trying to thread a needle some times.
- DonHopkins 11y agoTLDR: bla bla bla pie menus bla bla bla. ;) Fitts' Law inspired my work with pie menus [1] and gestural direct manipulation user interfaces over the years. [2] [1] Pie Menus on Wikipedia: https://en.wikipedia.org/wiki/Pie_menu https://en.wikipedia.org/wiki/Pie_menu [2] An Empirical Comparison of Pie vs. Linear Menus; CHI'88; Callahan, Hopkins, Weiser, Shneiderman: http://www.donhopkins.com/drupal/node/100 http://www.donhopkins.com/drupal/node/100 One rule of thumb which abides by Fitts' Law that I try to follow is: "the user's attention should not be squandered". [3] (So I apologize for being so verbose.) [3] BayCHI '98 talk: Natural Selection: The Evolution of Pie Menus: http://www.baychi.org/calendar/19981013/ http://www.baychi.org/calendar/19981013/ My goals have been enabling designers and users to easily create and edit their own pie menus, and providing smart editors, automatic layout, and support and guidance to help humans come up with easily memorable, Fitts'-friendly designs. This demo of an old OLE/ActiveX implementation of pie menus in Internet Explorer [4] shows the weakness and complexity of the traditional desktop gui MFC based approach to creating and editing pie menus with typical property sheets, scrolling lists and tree editors. [4] ActiveX Pie Menus: https://www.youtube.com/watch?v=nnC8x9x3Xag https://www.youtube.com/watch?v=nnC8x9x3Xag When editing a scrolling list or tree of items, it's difficult to visualize the directions, which change when you add or remove items. As the antithesis of direct manipulation, it takes far too much pointing and clicking to indirectly edit a pie menu via a scrolling list or tree control. Entering an indented outline into a text editor is an easy way to quickly define and edit a tree of pie menus and submenus, but it doesn't give you a good way to edit properties of each item. Of course describing menus in XML is great if you're a web server, but not fun for human beings. I tried to combine these different techniques of editing pie menus in a tabbed dialog, with a scrolling list and controls for editing items, a tree of nested items and a graphical preview, a text editor for entering nested items as an outline, loading and saving XML. But the result was a horribly unwieldy Frankinterface's Monster, difficult for a professional UI designer to use, and impossible for end users to use. These jQuery pie menus have a more evolved, web friendly design, but I haven't made an editor for them yet. Here's the documentation [5] and free open source code [6]. [5] jQuery Pie Menus Documentation: http://www.donhopkins.com/mediawiki/index.php/JQuery_Pie_Menus http://www.donhopkins.com/mediawiki/index.php/JQuery_Pie_Men... [6] jQuery Pie Menus Source Code: https://github.com/SimHacker/jquery-pie https://github.com/SimHacker/jquery-pie In the newer jQuery version, one change from previous designs is that I'm de-emphasizing the idea of "menus", and just calling them "pies", because I believe that framing pies as menus has too much historical baggage, does not emphasize their gestural, direct manipulative qualities, and precludes thinking of them more like a directed graph or geographical map, instead of a hierarchical tree. The jQuery and Unity3D [7] versions also differ from previous designs by modeling pies as containing directional slices, which themselves contain linear items, instead of pies containing items directly, and laying out all items in different directions, which change whenever you add or remove items. [7] Unity3D Pie Menu Demo: https://www.youtube.com/watch?v=sMN1LQ7qx9g https://www.youtube.com/watch?v=sMN1LQ7qx9g That enables designers to first specify the number of slices (which has a major effect on usability, with 4 and 8 being ideal numbers of slices), and then independently populate each slice with zero or more items, which users can select by moving out from the center. So the directions of the slices remain stable during construction and editing, because you can start by creating an 8 slice menu, and then incrementally drop any number of items into it each slice, or none at all. But why would you ever want to have empty slice, and why would you want the directions to remain stable and fixed to 8 slices? Kurtenbach and Buxton compared the speed and error rates of directional menus with different numbers of items, and found that 2, 4, 8 and 12 were optimal peaks. [8] [8] An empirical evaluation of some articulatory and cognitive aspects of marking menus: https://d2f99xq7vri1nk.cloudfront.net/legacy_app_files/pdf/93-p1-kurtenbach-empirical.pdf https://d2f99xq7vri1nk.cloudfront.net/legacy_app_files/pdf/9... With 2 or 4 items, Fitts' Law has an overwhelming effect, because each item's target area is enormous (1/2 or 1/4 of the entire screen area), and adjacent to the cursor starting position in the center of the menu. (Maximizing the area, minimizing the distance). The articulatory effects of Fitts' Law diminish as you add more items (the target area decreases, but the distance remains a small fixed constant), but there are other important cognitive effects that comes into play: the cognitive effort of remember the directions, and the mental framework you use to think, learn and recall. How many items are there, and what are their relationships? Are you ordering food from restaurant menu [8], or wandering around a Memory Palace? [10] [11] [9] Servitude: https://www.youtube.com/watch?v=NXsUetUzXlg https://www.youtube.com/watch?v=NXsUetUzXlg [10] Method of Loci: https://en.wikipedia.org/wiki/Method_of_loci https://en.wikipedia.org/wiki/Method_of_loci [11] iPhone app iLoci by Don Hopkins @ Mobile Dev Camp: https://www.youtube.com/watch?v=03ddG3jWF98 https://www.youtube.com/watch?v=03ddG3jWF98 With 7 items, there is no common English word or concept for all but one of the directions. But with 8 items, you benefit from the compass framework, opposite pairs, orthogonal axis, vertical, horizontal or diagonal patterns to use as a framework for arranging the items. And with 12 items, you benefit from the clock dial framework, as well as pairs, orthogonal and diagonal patterns, etc. But 10 and 12 items are past the "seven, plus or minus two" sweet spot. [12] So I'd recommend sticking with 8 items at most, unless your items semantically fit into that number of directions, like a 10 decimal dial, the 12 hours of the day, 12 months of the year, 12 signs of the Zodiac, etc. [12] The Magical Number Seven, Plus or Minus Two: https://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two https://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus... Kurtenbach and Buxton expected that the selection time would be monotonically increasing as you added more items, but were surprised to find that 8 items were faster than 7, and it kind of plateaued between 11 and 12. If you have 7 items, it actually helps to add a dummy item to even the menu out! That explains the "8 Days a Week" menu in this Dr. Dobb's Journal article, which adds "Today" to the top of a 7 weekday menu, splitting Sunday and Sunday, where it's always easy to select. [13] [13] The Design and Implementation of Pie Menus -- Dr. Dobb's Journal, Dec. 1991: http://www.donhopkins.com/drupal/node/98 http://www.donhopkins.com/drupal/node/98 In this MediaGraph demo [14], you can see two different approaches to pies working together. 1) Traditional hierarchical pop-up pie menus, supporting sub-menus, mouse ahead gestures, real time feedback, and pull-out items that use the distance as a parameter to the selection. (0:36 in video) Not editable by the user, but used to edit the other kind of pie. 2) Non-hierarchical free-form navigational pie maps, for arranging a map of songs connected with roads into a bidirectionally navigable graph, which enables users to easily hop around the network with quick flicking gestures (3:20 in video), and even create, edit and navigate their own pie maps via direct manipulation (4:07 in video). Editable and navigable by the user. Seamlessly integrated with panning and zooming gestures. [14] MediaGraph Music Navigation with Pie Menus Prototype developed for Will Wright's Stupid Fun Club: https://www.youtube.com/watch?v=2KfeHNIXYUc https://www.youtube.com/watch?v=2KfeHNIXYUc For more examples, here's a youtube playlist with some of my pie menu demos, in reverse-chronological order, which shows the evolution of designs over time. [15] [15] YouTube Pie Menu Play List: https://www.youtube.com/playlist?list=PLX66BqHq0qTCWwzRxTJ-XQ8o5vP7pjDbv https://www.youtube.com/playlist?list=PLX66BqHq0qTCWwzRxTJ-X...