Fitts’s Law in Design: The Perfect Fit for Ecommerce UX design
We have all wanted to turn website visitors into paying customers at least once in our lives. What if a little bit of knowledge and a minor fix could change everything around for an eCommerce website?
What if the visitors got instantly hooked after visiting your site?
Now, this is where Paul Fitts comes into play. He has done experiments and theorized aspects that have changed the very way humans interact with computers. He revolutionized the relationship between what we perceive and our attention span regarding what we visualize with his ideas.
So, what even is this renowned Fitts’s Law in Ecommerce UX UI design?
Fitts’s law states that the amount of time required for a person to move a pointer to a target area is a function of the distance to the target divided by the size of the target.
Thus, the larger the distance and the smaller the target’s size, the longer it takes to grasp it.
Fitts’s Law seems quite apparent when put in this light, not to say simplistic. And yet…
In 1954, the psychologist Paul Fitts evoked for the first time the basis of his theory on the mechanics of man and the prediction of movement. According to him, it is possible to calculate the act of pointing to an object, whether with the help of a computer mouse or a hand.
Even if not all designers are aware of this Law, it is apparent that it serves them when designing user interfaces.
But let’s not go too fast.
When it comes to encouraging visitors to become paying customers, small changes to an e-commerce site’s purchasing flow can significantly influence that. For example, designers may make it easier for consumers to locate exactly what they’re looking for, add products to their carts, and complete purchases by applying Fitts’s Law to an e-commerce site’s interface.
Fitts’s Law in Ecommerce UX design :
Speed At the Expense of Accuracy
Fitts’s theory is based in part on the work of the American psychologist Robert Woodworth. In 1889, he highlighted that the terminal variability of the movement depended on the speed of execution. This pioneering work has also led to consider that the time required to achieve a fast and precise hand movement is a function of both the amplitude of the movement and the precision required.
In other words, when a subject needs to point the fastest and most accurately at a target, speed is at the expense of accuracy. A phenomenon is also known as “conflict-speed-precision.”
In the reflection on ergonomics, and more particularly on human-machine interactions, it is thus estimated that:
The larger and closer the object, the easier it is to interact with it. Obviously.
Fitts’ Law in Ecommerce UX design: A Fundamental Law of UX
This Law highlights a relationship between speed and accuracy reported at pointing. Indeed, the most minor or most distant elements require more time to reach. This fundamental Law has excellent user experience (UX) and interface design implications.
Hence, when applied to interactive interface Ecommerce UX design, Fitts’s Law in design allows for a rule to consider when organizing the interface: a small target element will be less accessible. As a result, they will require more time to be pointed out.
Conversely, a large target object close to the user will quickly point.
Location and size reveal the priority assigned to the functionalities of an interface: the most critical and frequent functions will preferably be represented by larger targets closer to the user.
Fitts’s Law Ecommerce UX design, A Predictive Mathematical Law
To model human motion mathematically, Fitts invented this Law whose principle is as follows:
The time it takes to get quickly from a starting position to a final destination area depends on the size and distance of the target.
T = k log2(D/S + 0.5), with a person-dependent factor (~100 msec), D the distance from the target, and S the area of the target.
This Law can predict the time spent moving and select a target element. While it was developed to mathematically and physically model human movement, it is still used today profitably in human-machine interactions (HMI). Moreover, the Law takes on its whole meaning with the advent of graphical interfaces.
The “Comfort Zone” Of Graphical Interfaces
From Fitts’s Law, we better understand why there is a comfort zone in using graphical interfaces, desktop, and mobile, tactile or not.
Different devices with varying screen sizes affect the “comfort zone,” the screen space most easily reachable by the user.
The handling of mobile devices plays a significant role in the perception of this comfort zone for the users, whether they hold the screen in portrait or landscape mode, whether they are right-handed or left-handed, and even whether they use this or that model of the device, etc. In the mobile phone input distribution, the holding with the right hand clearly dominates the other grips.
The Desirable Location of Navigation
The handling of the mobile device is data to be taken into account in the Ecommerce UX design of the interfaces. This holding of the Smartphone, for example, induces particular comfort zones.
As for the interfaces on fixed screen (desktop), most often browsed with a mouse, the theoretical comfort zones are located at the 4 corners of the screen (because the mouse “blocks” by itself in the corners when it is “launched”) and around the cursor itself. But it all depends on the scoring systems used.
Desktops, where we see that the most easily reachable areas are at the 4 corners of the screen and at the edge of the cursor.
When it comes to mobile interfaces, the comfort zones are different depending on the format of the screen and its display mode. For example, in landscape mode, it is the side areas of the interface that the user will reach most easily.
In portrait mode, for a phone, it will be the lower-left corner representing the comfort zone for a right-hander. For a touchpad, these are the lower right and upper left corners.
Fitts’ s Law in design influenced the concept of the Prime Pixel, which refers to the placement of a user’s cursor at any given time. Designers of e-commerce user interfaces strive to reduce the distance between the prime pixel and the target as much as feasible.
Fitts’s Law in Ecommerce UX design for eCommerce sites
However, because the prime pixel is variable (who knows where a user’s mouse will be when they arrive at a page. lol), there are numerous approaches for managing the fixed components of an e-commerce page to arrange them as close to the prime pixel as possible.
Efficient Product Discovery Ecommerce UX design
Products are easy to find on successful e-commerce platforms. Adding search capabilities to the homepage’s hero section is one approach to applying Fitts’s Law to boost product discovery. However, scanning behavior and mouse motions are tightly related, and people prefer to scan online pages in regular patterns.
Placing a search bar in an area where visitors are likely to look—and so position their cursor to produce their prime pixel—could drastically lessen the distance they must move their cursor to type a search query. Furthermore, adding predictive search can assist consumers in getting to their desired listings faster.
A menu is an essential part of every successful e-commerce site since it helps customers quickly browse and find the categories and goods they’re looking for. Apply Fitts’s Law in Ecommerce UX design by:
- Implementing a drop-down menu that appears automatically when a consumer hovers over a content category.
- Avoid cramming too many items into a single list so that consumers don’t have to move their cursor too far to choose something.
- Use good information architecture and product photographs to give users greater target regions, which reduces the distance their cursors must travel to make selections.
Make certain actions more difficult than others
Fitts’s Law is commonly used by e-commerce UI designers to speed up user interactions. They may, however, want to slow them down in some circumstances. For example, designers may use little checkboxes for product add-ons further away from the prime pixel (in this case, a “Add to Cart” button). As a result, users will be forced to be more exact when selecting new products, ensuring that they do not mistakenly purchase undesired stuff.
Placement of the CTA buttons
Increasing the surface area of the Call-to-Action buttons is crucial for an eCommerce website.
A CTA button that will induce a purchase is a prominent area to apply Fitts’s Law.
- Make the button large so it sticks out and is easier to press; gaining a larger target necessitates less precision.
- Make the button stand out by positioning it above the fold, using accessible contrast, and placing it far enough away from other elements so that users don’t accidentally click on it.
- To bolster users’ decision-making confidence by ensuring that the button’s microcopy is clear and instructional.
- Consider positioning the CTA button at the screen’s edge to take advantage of so-called magic pixels, which are portions of the screen where a user can traverse fast and imprecisely while still striking the target.
Fitts’s Law in Ecommerce UX design: Conclusion
Even though Fitts’s Law was written decades before the internet, it is still helpful in digital product design. For example, Fitts’s Law in Ecommerce UX design may now be used by designers to increase income by making it easier for e-commerce shoppers to navigate a website, identify products, and make purchases.
It is imbued with a certain universality and is valid well beyond interfaces. However, it is the interface designers who apply it daily and must take advantage of it… with discernment. This “law” is not the only one to consider when designing: it is an aspect to which we must be sensitive, but we must not orient the whole conception around this single rule. The overall user experience of the solution may be degraded because the user does not necessarily seek to carry out his actions as quickly as possible! Hence, let your eCommerce website flourish by applying Fitts’s Law if you haven’t already.