User Experience Design: Fitts’ Law

User Experience Design: Fitts’ Law

Articles, Blog , , , , , , , , 5 Comments


Welcome to User Experience Design: Fitts’ Law. This learning module provides an introduction to Fitts’ Law and explains
how it’s applied to user experience design. Let’s start with: What is Fitts’ Law? To be honest. Fitts’ Law isn’t really
a law at all. It’s actually a descriptive model of human psychomotor behavior
that’s written as an equation like this one. In the formula, MT is the average time
to complete the movement. A&B are model parameters. D is the distance of movement
from start to target center. W is the width of the target Fitts’ Law is a model of human movement. It
tracks the time it takes to point at something taking into consideration the
size and distance of the target. So far this seems super confusing,
however; Fitts’ Law is easy-to-understand. Fundamentally, it proves that it’s faster
for you to hit larger targets that are closer to you than it is to hit smaller
targets that are farther away from you. If you look at the keys on your computer
keyboard you’ll notice that the keys users press most often: the enter key, the
space bar, and the shift key, are larger than the other modifying keys. These keys
are larger so they’re easier to hit. They’re also closer to the alphanumeric
keys. Keys that are used less often like: insert, delete, and escape are farther away
from the alphanumeric keys. User experience designers use Fitts’ Law
when creating user interfaces. Good UX designers ensure that any time they want
users to interact with the software or the interface they make it obvious.
Targets are easily located and easy to use. UX designers also know that the farther
away a user’s mouse is, and the smaller the on-screen target is, the longer it
takes someone to move the cursor and click on the target. We know that the size of the target matters. The larger the target
the easier it is to hit. This might lead a designer to think that the bigger
buttons are always better. However, that isn’t always the case. Fitts’ Law is a curve, which means that
smaller objects are easier to click if they’re made larger, however; larger
objects are already large so if they’re made larger yet they aren’t any easier
to click. Because of this curve the benefits of increased size begin to
decrease. This is actually good news for designers because it frees up more on-screen real estate and ensures on-screen objects are appropriately sized for
their intended use. Good on-screen target placement is
critical. As a UX designer the physical locations of your screen elements are
important. The gutenberg diagram shows that users tend to move through screens
from top-left to bottom-right. Therefore, consider placing what’s
important – like the buttons that call users to action, in the bottom right-hand
corner. When designing an on-screen layout, ask
yourself if your critical icons are the ones users are most likely to use?
Are they on the path that your users cursor takes? Remember to apply Fitts’ Law to your
design principles. When designing graphics, text, and screen
icons, always consider their sizes. Are they appropriately sized for their
intended use? Consider making any text labels into
links. Try making the whole phrase a link rather than just one word. On the Wisc-online website, the entire phrase “Switch to WTCS Categories” is a link instead of
just “Categories” or “WTCS.” This makes the target bigger and easier for the
user to hit. Keep in mind the devices that your customers are using. If you’re
developing a touch screen interface ask yourself: are the elements big enough and
spaced properly to allow your user to pick just one? The spacing between on-screen elements
is just as important as the size of the elements. Remember Fitts’ Law: it’s faster to hit
larger targets closer to you than it is to hit smaller targets farther from you. You have completed: User Experience
Design:Fitts’ Law.

5 thoughts on “User Experience Design: Fitts’ Law

Leave a Reply

Your email address will not be published. Required fields are marked *