Mouse Pointers & Fitts's Law - Computerphile

[@Marconius6]

"Because you can't miss the edge of the screen." And millions with dual screen monitors suddenly cried out... and were suddenly silenced.

[@TheCassual]

Marconius I've two monitors with the same resolution (1920x1080) and my cursor does get stuck in the right corners of the left monitor and left corners of the right monitor. Only happens if I slide the cursor in the bottom or top of the screen, however. I don't recall this happening when I had W7, but it does happen with W8.1 (plus I have some applications that remove the "hot corners" or whatever, and bring back the taskbar. Those might have something to do with it).

[@rjfaber1991]

Marconius That's why I've set my two monitors up in such a way that the primary monitor is on the right, and my secondary monitor on the left. It does make the Start button harder to reach, but I always just use the Windows key for that anyway, and it does mean that as long as a program is on the primary screen, I can close it very quickly and easily.

[@typorad]

millions?

[@ZipplyZane]

Marconius It's merely the same as if you resized the window smaller than your screen. Your virtual screen is just bigger. Plus you can always go to the left corner and double click

[@nihlesten5753]

With Win10, dual screen does have corners. To go to your next screen you have to pass through anywhere but the corners of your monitor.

[@BeCurieUs]

Ok, just started but I have to say that is the best hand writing of most any other guest on all the phile channels!

[@markstevens7699]

All?

[@BeCurieUs]

@@markstevens7699 Just rewatched, and the it still stands :D

[@neonblack211]

@@BeCurieUs I've always felt that females have better handwriting than males but that might just be a product of the fact im male.... I can't really think of a reason that should be true except that I myself am a male

[@MichaelKingsfordGray]

@@neonblack211 You are an anonymous liar! Why should anyone believe your claims?

[@MarkGamed]

You've heard of Fitts's law, but have you heard of Cole's Law? It's pretty tasty if you ask me

[@jcespinoza]

@@okie9025 I've been subliminally training my friends so that they understand this joke at the next gathering :)

[@christyjestin]

@@okie9025 I think coleslaw (or slaw) is pretty well known in the US

[@NworbMot]

Nice. I actually used Fitt's Law in reverse back in my Uni days, when working on ways to improve visual tracking of a user's hand in an augmented reality interface. Essentially using Fitt's Law to predict where in the large area captured by the camera, would be the most efficient place to search for the user's hand (or finger), based on their previous speed and location. i.e. If the hand was moving fast in a direction, the object or location the user was moving toward, was likely large and far away... if they were moving slowly... you could reasonably assume the next point to search the image for their hand would be relatively close and small.

[@LandonBrock]

Brady, do you ever sleep or just record and edit 24/7?! Keep the killer content coming, my friend.

[@Computerphile]

Landon Brock well, I did record but didn't edit this one... - Brady

[@LandonBrock]

Touché. Either way, you and Sean keep making it and us nerds will keep watching it.

[@celadewallace474]

They are supernatural science

[@timsmith3346]

He only runs about 30 channels.

What about IndoorsFengshuiPaintingphile?

[@TehBurek]

Just to confirm, it is in use, and it's studied in subjects like Human-Computer Interaction (HCI). I mean, as they've said, it is quite obvious and most people understand it intuitively, but professionals are (or at least should be) explicitly aware of it as Fitts' Law.

[@izabellejanzen7191]

TheBurek Yes, you would be correct. For most design purposes it's essentially codifying a set of intuitive assumptions. Most designers probably won't write it out on a day to day basis, but its important to keep in mind. It's most common and rigorous usage is actually for comparison of pointing devices. The a and b terms they are talking about can, if an experiment is run carefully enough be used to compare the effectiveness of say, a mouse to a joystick. Its actually part of the ISO 9241-9 standard for pointing device evaluation

[@TehBurek]

Izabelle Janzen Well said. Even if it is obvoius, expressing your assumptions in math, even if it ends up being simple math, opens it up to rigorous testing and essentially *makes* it science, rather than just people guessing things. That sort of thing is much more useful than people sometimes give it credit for.

[@davidflores909]

4:56 actually it is called "context menu" because it shows different items depending on where you right clicked.

[@SteveGouldinSpain]

You can't beat hotkeys

[@dekutree64]

Also mouse wheel. Both let you perform operations while keeping the cursor in its current position, which has major benefits in some cases.

[@SIeipner]

Well, sometime I just want to lean back and use my computer only with my mouse.

[@yeungfelix01]

yes when fast forward of a video can be done with mouse i will be very happy

[@HeroRaze]

Real men move their mouse pointer with the arrow keys.

[@ZT1ST]

Hotkeys have limits in what they can do - mouse pointers and Fitts's Law can do more than the limits of hotkeys, without needing to be remembered as to what they specifically do.

[@Jeyricho]

Honestly, the last bit where she puts words into something I've taken for granted since I first sat down at my Windows 98 blew my mind. It's an incredibly powerful thought that corners are infinitely large targets, even though I've already intuitively understood it for years

[@crabsynth3480]

I Loved How this Video was Edited.... When the Video changed to the Video in the Video Editor.... that was an Awesome Transition ! Kudos

[@Mar184]

Computer scientists and their obsession with log2... you could use any arbitrary base for the logarithm, it just alters your b, so there is no need to specify the base and it's in fact misleading (because it's highlighting an irrelevant detail). Might as well just write a+b*log(A/W+1)

[@robmckennie4203]

The handwriting in this video is top notch. A+

[@CrisWhetstone]

Explaining the corners or sides as infinitely big is very instructive. Another thing we have understood intuitively that an academic needed to describe it order to understand it consciously.

[@XiaosChannel]

The professor who improved fitts's law into today's form gave my paper a D. = =

[@jordanjohnson714]

...

[@ffccardoso]

that is such a achievement! Its worth a KZbin coment! Here, take my like!

[@CliveReyes]

"You cannot miss the edge of the screen." Apple: hold my beer...

[@sanderd17]

I'm missing predictability here. If a context menu is predictable, it's very easy indeed. But if the items you can choose vary widely, you need to search your item after the right click, which can be very time consuming. The same is true for menu bars where the items change on what you select.

[@tommytomthms5]

yes they forgot the slowest step! the "what am I looking at" factor or 'r' for 'recognition' I would put that right up in front, the most important step before witch the entire rest of the equation even begins

So basically Microsoft inverted this formula. Because otherwise I can't explain why they make some movable borders have a hitbox of one pixel.

[@PollPerson]

Were we following each other on Google+? You seem familiar lol

[@berkeleymorrison]

its 10 pixel not 1

@@berkeleymorrison I just found this comment again while my work laptop is running a program where I need to hit a 1 pixel wide border at least once per day. This definitely happens.

[@IsuAsenjo]

that's the most beautiful handwriting in all of computerphile and numberphile videos!!

[@CraparellaSmorrebrod]

It wasn't Apple who moved some buttons away from the edge, but Microsoft. And they noticed their mistake and fixed it later, to a certain extend. Apple actually used Fitts's law to great effect when they decided to place the menu bar at the very top of the screen, which also gives you a massive speed boost. Most windows application still don't place the menu bar at the very top of the screen, but inside a window.

[@soupy4099]

Craparella Smørrebrød looky looky what i see, a fucking circle, OH WAIT! There're 3! i.imgur.com/sBc58Ho.png

[@CraparellaSmorrebrod]

Soupy The video claimed that those windows management buttons were at some point placed at the screen corners and then later moved away from the corners on Mac systems. That's just plain wrong. Windows management buttons were never placed in the corners on Mac systems. Looky schmooky.

[@the80386]

Craparella Smørrebrød windows actually make up for the absence of top menu in a way. In order to access the file menu in mac, the window in question must be highlighted. If it's not, doing so is an additional step. In windows as long as you can see the window file menu, you can hit it without having to highlight saving that step.

[@Plutonia001]

Modern video game PC port developers like to add an additional variable into the equation. Mouse acceleration. Moving the mouse slowly moves the cursor a bit, moving it fast moves it a lot. So instead of the user having to only get used to a static ratio of mouse and cursor movement, they have the joy of constantly having to adapt to different mouse speeds. By ruining raw input like this, you can somewhat emulate the inaccuracy of cursor manipulation using a console analog stick. If one platform has a disadvantage, the other should too, even if they natively don't.

[@Alorand]

She has such clear and beautiful handwriting. Honestly, I am jealous.

[@uzimonkey]

A context menu has zero distance, but since the nature of text makes long, skinny boxes, the width as you're moving vertically is very narrow. This is why pie menus are preferable, it has the same zero distance but the width of each option is massively larger than a context menu. Using all 360* around the mouse pointer to max out the width was either an intuitive stroke of genius, or a very predictable result of Fitts' Law.

[@Gornius]

And that's why crosshair placement is so important in CS:GO, my dear silvers.

[@julian4064]

teach me :)

[@problemecium]

omfg why am I only finding this video today? This is an amazing insight and might well explain the trend of A: modern UIs having humongous text and buttons that consume lots of screen space and B: many modern UIs being terrible when they aren't arranged with Fitts's Law in mind!

[@TheRealBoof]

We use nearly the exact same formula in astrophysics to calculate a brightness metric called "magnitude". Specifically I am thinking of the bolometric magnitude (magnitude integrated over all photon frequencies): Mbol = Mbol,sun - 2.5 log_10(L/Lsun), where L is the luminosity. A very similar formula is used to determine distances to stars. The factor of 5/2 here comes from the arbitrary definition that an increase in magnitude of 5 corresponds to an increase in 100 in the flux (note the magnitude system is older than sin and was originally based on completely arbitrary definitions; used by the ancient Greeks etc). The reason why the equations are so similar is because this formula simply describes a mapping of one set of numbers to another, where powers are involved (i.e. 10^x).

[@joealias2594]

I don't particularly have a problem with the little window close buttons on new OS X systems, but I do have some older people in my family who use Macs because it's what they've always had, and I feel these are much more challenging for them. Sometimes I feel like computer designers have given up on older people and their usability needs.

[@david.stewart]

The infinitely wide corner button only applies to fullscreen apps. In a windowed app the corner buttons aren't infinitely wide because the cursor isn't bound to the app window. Likewise the infinitely wide corner button doesn't exist on stylus or touch devices because a finger or stylus isn't bound to to the display size and can overshoot the button just as easily as any other button (as noted in the video). The interestingly thing is that fullscreen apps tend to be predominately on touch devices, so the corner button idea is not all that usable in practice.

[@jblistener7491]

David Stewart Also, mobile devices generally require the user to physically handle the device, causing corner and side buttons to take on a dual role. This effectively divides their usefulness by the infinitely wide "handling" interface, and turning them into a pain in the neck, when you're accidentally activating them while manipulating or simply carrying the device.

[@ZipplyZane]

David Stewart The majority of users always use their apps fullscreen. And you've just described why Windows makes the Close button so big.

[@BGroothedde]

Did you mean a context menu? Not a tooltip menu, I assume.

[@csdojo6099]

For a while at 7:51, I paused and started refreshing my memory then I found below, thanks YT for the description section!

[@KrunchyGoodness]

I think you meant to say Musk was a part of PayPal.

[@brianlogan4740]

5 years later looking for this comment lol

[@toyuyn]

I can just imagine someone applying this to rhythm games like Osu!, Elite Beat Agents, Jubeat, Maimai and others.

[@PabloNeirotti]

Super interesting. I feel I should point out she got it wrong about Apple's UI on the Mac. On the top you always have the menu (which is therefore easier to click than other desktops). And so, the close or X button of a window is never on a screen edge, making its position in a window, be at a perfect corner or not, irrelevant, and not a slowdown.

[@gordonkeller6998]

Interesting that hover-expanding targets weren't brought up... I'd love to know how the effect of brushing over a target when traveling to it and having its size respond dynamically affects the equation.

[@radishpineapple74]

KZbin R&D needs to view this video: in full-screen mode, you used to be able to throw your cursor to the bottom-right in order to exit full-screen mode, but they screwed that up when they updated the player.

[@thomashome677]

So according to Fitts's law, Microsoft did a wonderful ui design in windows 8.1 with the charms bar, you have an indefinite target in the upper or lower right corner to open it, and then the buttons (charms) are close to the pointer and also very wide. They are even positioned closer to the pointer depending on if you use the upper or lower corner. When you use touch you just swipe from the edge, which is also a pretty easy target. Still most people think it is rubbish...

[@mamickabeegames]

Thank you for explaining this. I was wondering if the mouse sensitivity would change anything in the equation. 🤔

[@fnizzelwhoop]

The thing about Numberphile and Computerphile videos is that even the one's I think "This cannot possible be interesting!" about turn out to be interesting.

[@PeenutsPeenuts]

I would like to contend that the upper left corner "cross" on a mac isn't actually reduced entirely from infinite to simply it's size in practice.. Everyone that uses mac probably goes to that "infinitely wide" corner first and only has to correct a slight movement afterwards. Users still benefit somewhat from its proximate location to that infinite space.

[@otakuribo]

Yes. More design-related videos plz. :) She nailed it when she mentioned tablets and touchscreens. Does Fitts' law fall apart on mobile devices or do we need to just pick the right a and b values?

[@norbertfurst6293]

Nothing falls apart. There are just no infinite edges anymore. And you don‘t move a cursor on a touch device, like with a mouse. Don‘t get confused by a nice smile.

[@ThisNameIsBanned]

Id argue that the corners of a tablet would be incredible good places to put some functionality, as you can just hold the tablet with your hand and use these buttons with your thumb. Seems quite convenient for me, especially as most of the visual parts have a much more reasonable place in the middle of the screen, while functionality, like buttons, are more usefull around that, especially as the left/right edge of a tablet, to use with the left/right hand (even more so, if the tablet is in hands holding it like a big gamepad, then the 2 thumbs will be able to reach these buttons on the side much better, as you do not need to have a free hand to touch the middle of the screen). But ofcourse it highly depends on the actual application ; but the left/right side look particularly attractive to me to place buttons on tablets. Much less so for a desktop application, if you need to move the mouse from one edge to the other back and forth, menu at the bottom, menu at the top, drives me crazy ; dont even want to use that anymore. ---- Theres also potential ideas for "ring" layouts for context menues, which look particular fancy, and are much more convenient than the traditional "block" list that pops up. In the end, lots of UIs bank on what a user allready knows , and dont try to do anything new , as thats a pretty important aspect aswell (as i am much more likely to work with a UI i allready know, rather than a completly new form of layout). Might be a reason why so many wished for the old-school Windows Menu , as Microsoft removed it, and people suddenly could not even find the button to turn off the computer (as they allways found that in the windows menu, which was non existent anymore). Tiny changes, big impact.

[@quarkmarino]

Thats a REALLY beautiful hand writing

[@robinw77]

Good video! Close buttons aside, I'd always thought that Apple were pretty good in terms of this law, since the menu bar is always right at the top? Whereas with Windows, you need to go to the top of the current window, which won't necessarily be full-screen and therefore has a finite width. In terms of the close button, it seems both systems have difficulties. I don't remember it being in one of the extreme corners of the screen on OS X or previous versions of Mac OS. I've no real experience of Linux so can't comment on that one. Input welcome!

[@Soulzjd2]

This is a very good example on why applying concepts to 'variables' then putting them into a formula is so easy people do it when there is no need or real point to doing so. 5:28

[@RCapricot]

Couple of points: I don't think what apple did was silly at all, I think it was very clever. The X button is not one that you want to be pressing accidentally, it should be a very definite action and the smaller button allows that. Secondly, what about height? Surely width isn't the only factor in the size of the target. I know it's an extreme but what if you had a button that was as wide as the screen but only one pixel high? Then height is most definitely a factor.

[@kenna5031]

Wow... that hand-writing! I continue to be impressed!

[@emmey8865]

So a and b are basically your DPI and windows x/11 settings? (or in the case of game design ingame sensitivity as B or C depending on wether the game uses or bypasses windows settings.)

[@antonnym214]

I'm a writer, and i'm not perfect, but I can help with making a word ending with s as possessive. Properly it would be Fitts' law. Note we don't use two S at all, but we move the apostrophe to after the final s.

[@razzle_dazzle]

That is true for plurals - e.g. "citizens' rights" means the rights of citizens - but for proper nouns ending with S, either form is correct (so it can be Fitts' law or Fitts's law). Wikipedia has it as the latter.

[@tomlloyd2603]

Anton Nym both s' and s's are acceptable in this instance. Although, s' is what I would personally use.

[@TesikLP]

if the close button is brought a little bit away from the corner, it can still be reached by 2 movements, one large towards the corner (infinite object) and another very small to the button

[@johnfrancisdoe1563]

Tesik Fitts's law says that's not how humans work.

[@sequorroxx]

Fascinating stuff. I love how obviously interested Wiseman is in her subject.

[@zmix]

Something not mentioned specifically, but alluded to when they mentioned touch screens, is the difference between "relative" pointing devices, such as mice, trackpads, trackballs, etc, and "absolute" pointing devices like touch screens, Wacom and other "pen based" tablets. How does this difference affect the "weight" of the variables in Fitts's equation? It sounds like it was originally derived by using "absolute" position devices in 1954, such as a stylus and tablet.

[@Minty1337]

around 5:00 its a dropdown menu, the tool tip menu is within the dropdown menu.

[@NoriMori1992]

Sarah Wiseman playlist when?

[@BattousaiHBr]

***** correct me if i'm wrong but isn't the "s" after the apostle omitted if immediately before it there's another "s"? wouldn't it be Fitts' rather than Fitts's?

[@DjVortex-w]

BattousaiHBr Actually most English style manuals state that with proper names you should use 's for the possessive, even if the name ends with an s. Therefore, it's eg. "workers' rights" but "Fitts's law", because Fitts is a proper name.

[@almo2001]

About Apple moving the X. It's only infinitely wide if it's actually in the very corner of the screen. The close-window button isn't in the corner of the screen... because of the menu bar on top. You could argue THAT was a bad idea, but changing the close box to a circle didn't really change anything. It also only applies on Windows if you happen to have your window full screen size (or wedged up into that upper right-hand corner). And if you look at the Platinum (circa System 7) close box, it's not the full size of the window's title bar anyway, so this was probably always how things worked on Mac OS.

[@ZipplyZane]

almo2001 She didn't point out that, while corners are infinite in two directions, the edges are still infinite in one direction, and can still be useful. It's why web browsers let their tabs go all the way up in full screen, too. I'm actually surprised No one has put the tabs in the menu bar when going full screen. It's not like web browsers on other platforms have visible menu bars...

[@holdintheaces7468]

Cmd+Q or Cmd+W is why Apple changed the close button. Keyboard shortcuts seem to be more important and more universal on OSX

[@PhilNEvo]

I think the equations missing something when you talk about Apples button. Since you can't miss the mark with a lot since if you overshoot "too much" you'll be stopped by the edge, and don't have to take a lot of time to correct it. Whereas a similar size button further from the edge can be overshot by a greater distance, making it more likely, especially for beginners, to overshoot multiple times as they try to over-correct.

Mac red round button doesn't have the same function as the Windows corner X button. In Windows, the X quits the app. In Mac, round red button only closes currently open document. The app remains open. The latest version of Windows gave that "X" dual function; if you have multiple documents open, "X" will only close a document window. However, if you're clicking that "X" and only have one document open, suddenly, you are quitting the whole application instead of just closing a document. In Mac OS, this is consistent. Red round button in the corner will always only close that window and nothing else.

[@Monody512]

Honestly, I rarely have a program's window filling the screen. It'll either be smaller than the screenspace, sitting somewhere in the middle, or fullscreened, meaning the top bar is hidden until it's needed( but I mostly just use keyboard shortcuts).

[@jaimecristalino]

your video style is unique and incredible! that's amazing!

[@BariumCobaltNitrog3n]

The corners of my Mac are not infinite clickable spots, they are functions. Live corners or hot corners, they have different names, but if you move your mouse up and to the right past the corner, the screen saver will turn on. The lower left corner brings up the Dashboard containing calendars, calculator, note pad and more (it's editable) and the upper left corner makes everything disappear to see the desktop and access it. The lower right does nothing, but there is never a clickable box there anyway. Also, Dr. Sarah uses "actually" similar to Americans using "like", no meaning change when removed. Good vid Brady. I personally want the eye-tracking hardware so I can look-and-blink instead of all this carpal tunnel inducing mouse-and-click nonsense.

[@toddblackmon]

The log2 is interesting as well. It creates a sort of diminishing returns effect on your adjustments.

[@erickleefeld4883]

Apple’s main application of Fitts’s Law on the Mac is that the menu bar for applications is always at the top of the screen. You just rush your pointer upward, and it’s there.

[@ACDCBoy62]

I wonder how Fitts' Law could be expanded to account for learning curve. No matter how difficult a target may be to hit, muscle memory would undoubtedly decrease the time that takes. Or, is that one way one can use "a" and/or "b"?

[@Verrisin]

How to make really *quick to use interfaces*: Minimize time when mouse is required*. (* Applies to pretty much everything but drawing) (tip no 2: make user know what to type before he starts & make it short) - examples: Vim, Emacs, (surprisingly**) Word, tiling wm (** I feel like nobody is using it, but starts the mode) //btw. I'm not even using vim/emacs much, but it's the truth. //of course, sometimes you only have 1 hand on the mouse and eat with the other or something; then this doesn't apply...

[@veggiet2009]

You should do a video about different shaped buttons. I've used programs that use circular buttons, these are quite difficult to use in my opinion, but it would be interesting to know the mathematical difference between a square target w=2 and a circle w=2 (or diameter = 2)

[@dnarbredlih]

2 x 2 = 4 = area of the square. 3.14(2/2)^2 = 3.14 = area of circle. The square will always be bigger if n equals width of the square and the diameter of the circle.

[@StormHeflin]

+dnarbredlih You can't square a circle. So for a circle to be as accessible as a square, the circle would need to be bigger. Just a little thought, don't mean to start an argument or something.

[@dnarbredlih]

I think we just said the same thing, dude.

[@StormHeflin]

dnarbredlih I was half asleep at the time, sorry. Haha

[@rasjnda]

I couldn't find a comment about Dr Sarah Wiseman being Fitt so I have to make it myself. I am not proud of myself but I cannot let this pun go to waste.

[@Kradrling]

This is one of the many reasons windows 8 failed. It tried to use the same interface for computers and tablets and phones.

[@HerrEndstiller]

I get that the corners are "infinitely wide", since you can't miss them by the x and y axis when you just move to theyr direction long enough. But what about the edges. On the right hand side for example where the -x width is infinite, but you can still miss on +/- the y axis. Whats the width of a Target on the edges. Probably not 1/2 infinite, but neither is it just it's width... whats the formular there?

[@Qbe_Root]

On Ubuntu (with Unity), the X button is also a circle, but you can still click in the corner.

[@ollllj]

something that is sadly not done enough is a right click menu that uses 4 directions for sub-menues. that way a menu tree becomes like "gesture recognition". the game "sacrifice" did this nicely.

[@Kitsunary]

I don't know why people would care, but it is okay to use Fitts's or Fitts' in a paper as long as you are consistent with which one you use. They are both technically correct as Fitts' is the more old fashioned version while Fitts's would be how such things are taught now. There are still disagreements about this, but there are many people on both sides, so either will work.

[@Zalaniar]

Interesting video! Does the height of the target also factor into the equation somehow, or is it only the width that truly matters?

[@NortelGeek]

The "tooltip" menu is called a context menu. Great video, thank you!

[@AllanBrunoPetersen]

What about targets you don't look at..? ;) Take the Windows scrollbar in most Windows applications - if you grab it and scroll through a long list/page while watching the list/page.. Especially with high DPI mice, staying within the invisible boundary through a long scrolling session gets tough.

[@j7ndominica051]

Microsoft wasn't aware of the Fitts' law when they started spreading items around the whole screen on the Metro interface. And here's Apple who can do no wrong in design. They intuitive choice would be to make the corner area be the functional button, despite that it's drawn smaller or round further away from the edge. The close buttons and the taskbar buttons on Windows Classic are 2px away from the edge (we can clearly see the border in Classic). The close buttons work as expected, and the mouse jumps up when clicked below the taskbar. The mouse "Acceleration", which is used to compensate for low resolution mice (called "Enhance pointer precision" in Windows, actually - _lower_ the precision at high velocities), must severely impact the formula, if it takes a varying amounts of movement of the hand to move towards the target and then back from it. The hand gets confused as to how far it needs to move and must constantly hunt for the speed and compensate.

[@Diggnuts]

MacOS(X) never had any infinite top left or right width window buttons ever, because there has always been the menu bar under which no window top can move. The Apple icon and spotlight are infinitely wide.

[@timorautiainen1783]

This is just a guess, but could it be that as corners of the screen are points where cursor will no move forwards of on x,y scale to that direction. The size of the X does not matter anymore as the cursor will be on it just by flicking your wrist to that direction. This obvilously applies to those who know where spot marked with X is. Which is the top right corner of your screen.

[@MosesTemu]

Makes me think of how IE has "open", which is the same as a left click, at the top of its contextual menu, rather than the option to open in a new tab, like other browsers do.

[@AnimeReference]

The problem with just placing buttons in corners is that if you add a second monitor then you can overshoot. Additionally this formula ignores the size and number of other targets (Hick's law). Say for example you have a 2x1 pixel screen with two buttons a and b. It's as she said, easy! Now consider a 3x1 screen with buttons a, c and b - it's notably harder to press the 'b' button. Now consider the screen 102x1 with 'a' and 'b' on the sides both one pixel in size and c in the middle at 100 pixels in size - it has gotten even harder again. Too many interfaces use Fitt's law in this way and you get bad user interfaces. Right click somewhere on this page and note how many icons you get. On chrome I get 11 items divided into 4 sections. Not only is it hard to click on the right option, but now I have to read them all. Would it not be better for a right click to bring up four context menus? Or how about a gesture of a combination of a right click and an up/down/left/right mouse drag to bring up only the section I want? Better yet you get a fullscreen overlay (though the failure of windows 8 proves how users hate this) and four buttons appear and they are selected by moving the mouse up/down/left/right ignoring starting position completely (think joystick menu). There is a lot more to designing a UI. You don't just have distance/size, you also have number/size of items, number of clicks, the cost of moving from mouse to keyboard, the learning curve / intuitiveness, etc Just some food for thought.

[@smurfyday]

Macs took forever for the right-click. Microsoft built it in almost from the beginning.

[@yousafe007]

That's coz you never need them on a mac.

[@treahblade]

Lies you use them all the time its just your trained to use the super user key.

[@yousafe007]

+treahblade yes, we do. The point is how we use or access the secondary drop down menu.

[@yousafe007]

+Çerastes okay. You're one huge "knows-it-all" it seems.

[@yousafe007]

+Çerastes as you say sir.

[@slpk]

Shouldn't W be the area instead of the width? Also, the menu that pops up next to the mouse when you right click is called the context menu.

[@bealz3130]

***** contextual menu

[@UMosNyu]

***** I am with you. Shouldn't the width go in the same direction as the amplitude? (Also since noone can have and keep an exact angle, shouldn't an angular tolerance be part of the law too?)

[@magzthepro]

I think it should be the smallest distance between 2 points which have only the action between them.

[@orokro_stuff]

sandy crack I don't think it should be Area, instead width should be diameter. Consider the following two examples, which is easier to click on? Clicking on a 30px x 30px square (area is 900px) OR Clicking on a 1px x 900x line (area is 900px) Obvi clicking on the 30x30px square is easier than the 1x900px line, but they both have the same area. Instead, if you consider your targets roughly as the circular region that they occupy, then thinking of the target as a diameter makes the most sense.

[@-morrow]

hypurban the diameter only works for circles obviously, for rectangles I would use min(W, H). This would give the highest possible value for squares (easiest to hit) and the lowest for lines (hardest to hit).

[@alecjohnson55]

I can't remember the last time I actually used the mouse to close a window that I didn't have to; keyboard commands are the best! But it is really cool to consider that the infinite width is not taken advantage of in so many ways. Maybe I should put some things in the bottom right and left of my screen

[@zombiedude347]

Unless it was named after multiple people named Fitt, is is Fitts's law. -'s vs -((e)s)' is based on grammatical singular vs plural, not if it ends with the letter s. Same reason a vs an is based on spoken vowel, not written vowel. Silly comment section.

[@Cloud98]

That's odd if you think about the equation, because the equation didn't seem like it's a function of time. Unless a and b were one of them. Would've liked to see a demo of the equation (e.g with this amplitude, width, and length, you'd get 200 ms.)

[@DrRChandra]

I don't know if we can genuinely say "width," but that's how it's formulated. Imagine if the target is the width of the screen (say 1920 pixels) but only one pixel high. I would have thought area would be closer, but also aspect ratio has to figure into it.

[@Excludos]

a lot of designers go overboard with this, especially the W. "How do we make this design more intuitive and win prices?" "We make every button take up half the screen of course!! Forget the information people actually want. Big buttons is where it's at!"

[@BrandNewByxor]

I find it weird how the height of the target isn't considered in the formula. Surely a target with of height 1px will take a lot longer to click than a target of height 1000px.

[@MiniDemonic]

7:50 no, he is not one of the cofounders of Google.

[@256shadesofgrey]

Now that you've mentioned it, I'm curious about the formula for the touch interfaces.

[@norbertfurst6293]

It‘s the same - just different from what you do with a dragged cursor.

[@Veginite]

5:42 - It isn't infinite if you have a multi-monitor setup and the window you're about to close isn't on the edge screen.

[@Alex2Buzz]

You can use both "Fitts's" and "Fitts'" (single apostrophe at the end of "Fitts").

[@MathAndComputers]

Sadly, on dual-monitor setups, at the "edge" between the monitors, it becomes painfully clear how thin scrollbars and the like are. I find it's reliably faster to get to them if they're moved inward from the virtual edge a bit.

[@ambydupuis]

As a software dev, this was a very interesting video. Thank you.

[@MasterGhostKnight]

This "corner being" trick infinite does not apply to mouse pointers. Anybody that works with multi monitors would be able to tell you that. If you put something at the corner at the other end of the other screen, it is going to take much longer than to reach something at the center of the screen where the mouse is at.

[@walter0bz]

6:26 you don't close applications often . using the top edge for a menu is far more useful.

[@aceban5441]

About the formula of the Fitts's law I was curious about the a and b variable, can you expalin again about those variable and why it should be ignore? I'm kind of curious and didn't get well.

[@ThatUnfunGuy]

The problem with corners is people using multiple extended monitors. Because software devs are using the corners as infinite, but with extended monitors it isn't infite at all!

[@torlumnitor8230]

Watching this video on my phone and where does KZbin have the buttons? In the corners. Did they consider this equation when designing the app?

[@AndrewMeyer]

5:24 Before watching beyond this point. Let me guess... the edges of the screen. (E.g. The tabs on my browser window, the close button on any full-screen window on my computer, etc.) Right? You've essentially got infinite "width" there.

[@ThisNameIsBanned]

Obvisiously we use Hotkeys and Shortcuts and dont use the Mouse, as thats just plain slower. Programmers perspective atleast.

[@scotts1138]

This law is missing one important aspect, the height of the object. You can have something quite wide but with height neglected does raise questions. Based on this law therefore 2 objects with different height will have the same results whether 1 pixel high or 100. As distance can be the same and it's location. (lets say a pure horizontal movement for instance) or even vertical move it is still harder to click a small icon even if wide. Still useful but I'd like to know how you factor in this part to decide how high some object should be.

[@PeterWalkerHP16c]

+Scott Simmons The reason it called a law is that it has been found experimentally accurate in many studies. If you feel it is in error then by all means do the studies and publish. Here's the physiological basis. Relevant human motor function vector error is more pronounced in direction than magnitude. Another thing missed by most commentators here is the width is effectively measured *perpendicular* to the direction (angle). Perhaps this was not made clear in the video.

[@mariustancredi2192]

Width is the shorter side of a rectangle.

[@PeterWalkerHP16c]

Marius Tancredi So why do we call them wide screen TVs when talking about the width?. Why is a property frontage measured as the 'width' of a block? Why do fish tanks call the longest side the width of the tank? Wide windows vs tall or long windows? When talking about monitors the width in terms of software is always horizontal.