Fitts Law in UI Designs
Applying Fitts Law in User Interface Design not just enhances the User Interface Design but also creates an amazing User Experience (UX) for the target audience.
Sometimes applying some small tips and tricks on designing the User Interface can increase the number of target audiences in turn making huge sales conversions. Applying Fitts’ Law in User Interface Design not just enhances the User Interface Design but also creates an amazing User Experience (UX) for the target audience. Being a UI/UX designer having an understanding of the Fitts’ Law does not just help you only with the improvements in the User Interface design principles but also help you gain foresight in business terms. This article is a guidebook on the terminologies related to Fitts’ Law and its relevant applications. Let us deep dive and gain insights exploring the same together through this article.
Renowned psychologist Paul Fitts invented the Fitts’ law in the year 1954. It is an empirical model on human eye movement and the interaction of human beings with computers. Fitts’ law finds its significant application in the ergonomics system and eye-tracking. It is a scientific law that helps in the prediction of time considering two parameters that are the width and the distance of the target. Let us also understand a few technical equations on Fitts’ law and then find its relevance in User Interface design.
The mathematical equation of Fitts’ law is as mentioned below:
t = a + b log2 (2 d/w)
Where t is the time quotient; a and b are coefficients that are taken from multiple observations or testing scenarios; d is the distance measured between the start point and endpoint;w is the width. The mathematical equation of Fitts’ law is on a logarithm scale and log2 (2 d/w) is the difficulty index. This calculation then determines whether the target is achievable or not.
In addition to this, there are two tasks involved in terms of movement in Fitts’ Law:
- Initial movement: Imprecise yet fast movement towards the set target
- Final movement: More precise when compared to the initial movement and slow in speed
Conclusions from the mathematical equation are such that for larger screen sizes relevant increase in the distance might make it difficult to reach aimed target whereas smaller screen sizes can afford a slight increase in distance or screen size.
Fitts’ law finds its significance and relevance in User Interface design principles as it helps in deploying the technique of reducing the time taken by the cursor or finger to reach the target UI component or UI element. Two parameters every UI/UX designer should consider when applying Fitts’ law are first the size of the set target UI element with respect to the other UI elements available on the interface. The second and the most important is the distance calculated from the target and cursor. Applying Fitts’ law in UI design makes the designs more interactive leaving one of the best visual impressions on the target audience.
Practical applications of Fitts’ law in UI design:
Implications of the Fitts’ law in User Interface design that helps in better user experiences.
- Command Buttons - A clear distinction must be maintained in the User Interface design between the interactive and non-interactive elements. The surface area of the command button is what decides the level of precision. The larger the size of the button more visible it is and this makes it easier to click from the pointing device.Smaller the size of the command button the level of precision goes on increasing making the UI object less clickable.
- Edges and corners of the User Interface - GUI (Graphical User Interface) is more sensitive with respect to the other screen area. Due to the pinning action, the GUI space is the most speedy than anywhere else around the screen. The outer edges and peripheries are well defined to avoid any clicks beyond the predefined space by the user community.
- Pop-up menus - Another user interactive alternative that helps in reducing screen time is pop-up menus. They narrow down the selections adding only the relevant UI elements in dropdown menus. And so the user does not have to move much from the cursor or finger.
- Selection options - There are two selection options that are vertical and horizontal within the linear menu. The click time increases when the UI elements are placed in a circular format. Wedge-shaped buttons face the maximum errors in UI/UX design.
- Taskbars - Not talking about the Fitts’ law of User Interface design but speaking in layman’s terms more than one taskbar is embedded in the user interface design then there is a potential confusion factor that is raised in the user community. Screen engagement should be with minimal clicks and less confusion.
Major takeaways from the guidebook on applying Fitts’ Law in User Interface Design:
The application of Fitts’ Law in User Interface design principles makes the UI elements more interactive as they appear on the graphical displays of either mobile or web applications. The size of the UI element and distance are the potential parameters considered when calculating the time to reach the set or selected target. For comparatively smaller UI elements that are placed far from the cursor or finger increase the time of selection. The primary focus of any UI/UX designer should be placing all the User Interface objects close and in a compact fashion. Interactive UI elements should be larger in size and easily visible to the user community. A prerequisite of any UI design is the minimal usage of combination features. Hire UI/UX designer who will help you bring your business ideas into reality. They have a versatile skillset ranging from wireframes to User Experience design.