User Experience (UX), User Interface (UI), Human Factors, and the difference between them

Frank Zinghini

Founder & CEO

There are a number of reasons why the user’s experience  – and user experience design – are more important than ever:

Users talk. Users can talk to other users about their experiences quite easily now. If your application is usable, intuitive, and highly functional, users will tell each other. If it isn’t, even more users will tell that to each other – and it will be very difficult for you to overcome those negative, customer-to-customer perceptions. There are now a number of sites where users can share their experiences, such as GetApp, Capterra, and FinancesOnline.

Competition has exploded. Application development has become incredibly competitive. The number of applications available for any given type of function have grown exponentially in the last few years.

First they try, then maybe they buy. Users jump to trial mode very quickly when looking for a specific application. In the first few minutes of taking your application for a spin, the users will decide if it is user-friendly or not. If not, they will keep searching and you will lose the sale.

User expectations are at an all-time high. Popular and intuitive everyday-use sites such as Amazon and Uber have set the bar for usability. And your competitors probably know this as well.

Developing applications for users

As important as these trends are, it’s surprising how much confusion there is about usability and how little discipline there is associated with the process of building usable applications. Part of the confusion stems from a lack of clear understanding of the differences between three distinct usability disciplines: User Experience Design, User Interface Design, and Human Factors analysis.

Before we go into detail about each one, let’s start with some simple definitions:

  • User Experience (UX) is just that: how does it feel to use your application. User experience design is the process of making your application feel good: pleasant and easier to use.
  • User Interface (UI) is the actual blueprint or architecture behind the UX. User interface design is creating the structure to actually achieve the UX that you hope for.
  • Human Factors is the study of human behavior as users interact with the physical world or with a system. In application development, it looks at issues such as how people react to things they see on a screen, or how they remember things.

People working in these usability disciplines are advocates for the user. They are doing everything they can to make sure that the user is satisfied with the application. Their commitment to the user’s satisfaction goes beyond just making sure that the user is getting the job done; but also that they are enjoying themselves as they are getting that job done. For example, a task management application might have a way for you to grab and drag a task box from one column to another. The act of moving the card to the new column is more satisfying than, say, copying information from one cell to another in a spreadsheet.

User Experience

Let’s start with a really simple example of UX thinking. Have you ever used an application where you’d click on something and nothing would apparently be happening, until it did? Any capable UX designer would ensure that there was proper feedback when you interacted with an on-screen element. It may be a simple visual reflection of the action, or a more detailed indication of what is happening, but in any event the designer will ensure that the experience of clicking that element is pleasing and effective.

If a user clicks on a button and nothing happens, that user will be stalled, wondering what state the system is in, wondering if what he or she did actually “worked,” maybe clicking the button again and messing things up. This is the opposite of pleasing and effective.

This is a simple example but it demonstrates something important: at the core of UX design is empathy. There is no substitute for walking a mile in your user’s shoes. How do they think? How will they want to interact with the product? What are they trying to accomplish? What would make them happy to use your application?

User Interface

UI is a subset of UX. UI provides a blueprint for the graphical aspects of the UX requirements. In other words, what is visually or audibly presented to the user.

The UI designer concerns herself with typography, color, style, size, brightness, contrast, color, placement, the proximity of one element to another, repetition of elements, simplicity, and clean design. How do you make things more readable? How do you make the elements visually distinct from each other? How do colors interact?

UI also concerns itself with where the buttons (interactive elements) are placed on a page. How are the elements treated, in terms of their importance? How can color, size, and placement be used to make navigation obvious? Which typefaces are most appropriate for the different types of content?

The UI person will also be concerned about the adaptability of the design to different devices – computer screens versus mobile devices versus specialty kiosks. Each type of screen requires a different approach.

Human Factors

Human factors is the study of how people behave and react. When applied to application or system design, the goal is to determine how people behave and react as they interact with the application or system.

The discipline of human factors analysis grew out of aerospace, where the goal is to understand how people interact with powerful, sensitive machines and perceive things via touch, sight, and sound. This discipline has grown to encompass all interactions between humans and cyber/mechanical systems. In a sense, now, you are trying to successfully integrate protein (people) with silicon (technology). The aerospace application is less concerned with “enjoyment” and more concerned with keeping the operator alive: landing the plane; docking the spacecraft; delivering bombs on target; delivering supplies; or extracting wounded personnel. They are focused on the effectiveness of the mission.

One of the more interesting aspects of human factors design is how we humans perceive the world around us. We are only aware of about 2% of our surroundings at any given moment. As long as nothing is amiss in the other 98% of our environment, we are able to focus on the 2% that matters.

If something doesn’t match up with how we are hard-wired to perceive our surroundings, our brain will interrupt our focus on the 2%, and divert our attention to the unusual. For example, if you are walking in a park and suddenly see someone accelerate from zero to 20 miles an hour, you are going to stop walking and stare. There is a natural acceleration and deceleration in our physical world.

We use these precognitive effects in developing software, with visual cues and animations designed to trigger a response in the user. But this is a delicate line to walk: animations in the virtual world need to reflect this reality, or the mind will become distracted from the task at hand. It’s not enough for something to “look nice.” It also has to support and enhance functionality. These physical aspects need to be incorporated into the design of the application in a way that is natural and meaningful to your user.

The importance of accepted conventions

One of the interesting factors in all three of these disciplines – UX, UI, and Human Factors design – is the role that accepted conventions play in the design process. Certain conventions develop over time, such as a colored button at the bottom of a web page, or the use of swiping a finger to move a list up and down in a mobile app. A successful application development process starts with the acceptance of these conventions.

It takes several years of experience to identify standard conventions, and to determine when it is appropriate to deviate – even just slightly – from the convention, in order to make an improvement. Deviations are more dangerous than designers might assume. Ignoring them, or trying to be “creative” in an area where the user expects something “standard,” can cause usability problems. Deviations are distracting, confusing, and reduce the satisfaction that the user will have with the application.

Design constraints

In the ideal world, where you had time and the full cooperation of your design team, you would start with user interviews and observations to determine what the user wants to do, factor in conventions, and figure out how you could improve on the experience. As the user advocate for the design, you would then take your analysis to your developers, who would factor your recommendations into the design.

In the real world, many companies skip over the usability phase altogether. Or, if there is someone taking usability recommendations to the development team, they are often met with resistance. “That would take too long or be too difficult, because of the technical architecture of the system.” “We don’t have the time or the budget to build all this into the application’s first release.”

Most managers try to pick their battles in order to make the right decisions. Obviously, you can’t afford to spend 80% of your resources on usability. Something else is going to suffer. On the other hand, if you don’t put enough emphasis on usability, you will create an application that no one wants to use – or buy.

The user interface aspect of a system is also constrained by what the underlying application development environment is capable of accommodating. From a usability perspective, the development effort will fall flat if the design is centered only on what the underlying platform can deliver. But making it do the things that you know your user really needs is going to take work.

Another restriction that always affects usability is time. It takes time to conduct pre-development user research, to create prototypes, get user feedback, create new prototypes, and check performance at every step. Market windows don’t stay open very long. The old saying, “There’s never enough time to do it right the first time, but always enough time to do it over,” definitely applies to usability.

In the new world, there are many companies now working at cloud speed. They test the application for usability by creating it, taking it to market, and then rapidly refining based on feedback. They also have the advantage of seeing how users are interacting with the cloud-based application. Gathering and analyzing that data, in conjunction with user interviews, can teach you a great deal, fast, about the usability of your application.

Even if you use this method, to ensure even the most rudimentary user acceptance right out of the gate you need to know and agree on:

  • The type of user you will focus on first
  • What the conventions are for those types of users
  • What users would like to see
  • What frustrates them about similar applications
  • What others are doing in your space
  • The main functional objective of the application
  • How the design can be made as simple and straightforward as possible

Users are full of surprises. It is quite common for developers to develop an application and for users to use it in a completely different way than the developers intended. It is depressing and financially dangerous to find this out after the application has been developed and launched. It is better to find out during the development process. Yes, market feedback will always be a factor after the product is launched, but skipping the research entirely at the beginning, or just paying lip service to it, is very expensive.

Strategically, there is a way to approach the whole usability exercise by asking yourself a simple, but powerful question: “What is the ultimate objective of the user?” It is never just “get this project done,” or, “talk to my friends,” or, “keep track of customers.” The real objective is far more profound and important to the user, as in, “Zip through this process smoothly and quickly, with no distractions or frustrations.” Or, “Be able to contact anyone, anytime, from the same application on different devices.” Or, “Know which customers most urgently need help, now.”

Don’t assume you understand these objectives and their subtleties. No matter how smart you are, you are at a disadvantage. You are the developer, not the user, and it is literally impossible to think like a user if you are the developer – unless you interview your users, watch them work, and interact with them as you develop your ideas.

Usability pays

Companies that have made usability a priority – Apple always comes to mind first in this context – have been able to release products that were not “first” but were definitely “best” in terms of usability. Customers will pay a premium for something that goes beyond their expectations and simply “works.” Market differentiation via superior usability takes on its own momentum. Users comment on it to others; they use the application more than they would otherwise, and are observed using it.

Usability is, in a sense, the most powerful form of marketing, and a time-tested trigger for word-of-mouth recommendations.

For more information on application development and design, please download a guide for CEOs about creating great software from Applied Visions today.

hbspt.cta.load(2637494, ‘7be9b60b-533e-4a11-9fb1-d6f541024810’, {});