Introduction to mobile UX and usability testing

by Patrick J Quilter, Jr.

In the early days of e-commerce, development teams could get away with skimping on user experience (UX) design. It was perfectly acceptable to overload a user with a long list of text boxes and dropdowns to be filled out. Today, all that has changed because of mobile technology. To truly appreciate the impact mobile technology has had on design, it is necessary to understand the modern discipline, process, and complexities of UX.

Understanding the discipline of modern UX design

The Oxford Academic article "UX Curve: A method for evaluating long-term user experience" defines UX design as “improving customer satisfaction and loyalty through the utility, ease of use, and pleasure provided in the interaction with a product.” UX design seeks to optimize the amount of input required from a user to deliver a meaningful experience. In the technology industry, it is where cognitive science meets digital media. In academia, UX is a topic in the field of human-computer interaction (HCI).

Product designers know that they can gain a competitive advantage by focusing on superior UX design. This is particularly important for startups and organizations with small budgets. User attention span has proved short, with approximately 23% of users abandoning apps after using them one time. An organization that plans a better UX design can usurp established institutions. The design areas of focus include:

  • Clear, built-in directions on how users are supposed to interact with a product
  • Simplified presentations of complex industry business practices such as those found in retail, entertainment, and finance
  • Content-rich experiences that drive users to return to a product
  • A feeling of security, particularly with online payment products

The Nielsen Norman Group, with over 40 years of software design and development experience, estimates “that it's 100 times cheaper to make a change before any code has been written than it is to wait until after the implementation is complete.” Organizations that want to capitalize on this fact will diligently build comprehensive UX design plans and test processes that evaluate user feedback before allowing development activities to begin. A streamlined UX design process will avoid heavy up-front planning and iterate through several rounds of brainstorming, testing with real-user analysis, incorporating feedback, and retesting.

Process and tools for UX design evaluation

Techniques for building a UX design process vary in sophistication and are commonly referred to as having either low or high fidelity. Cost is an important factor when deciding which fidelity to implement. This is particularly important for startups looking to raise funding and stretch every dollar. They may choose to implement only a few techniques, but, ideally, an organization would incorporate several and progress from low fidelity to high fidelity as follows:  

Paper prototypes (low fidelity)

Representing the software design on sheets of paper  is the first step in the process of laying out diverging perspectives. A facilitator places individual sheets of paper in front of a test user, allowing her to treat each sheet as a software screen. The facilitator (and other observers) are measuring the intuitiveness of their intended design. Check out this demonstration, embedded below.


Wireframing (low to medium fidelity)

This is where the convergence process begins, as design ideas and assumptions are eliminated due to the vetting process from the paper-prototype iterations. Here, designers more tightly illustrate the visual representation of a user interface (UI). This becomes a blueprint of the interface layout and content so that, once again, a facilitator and test user can iterate through several possibilities in something that resembles a digital format.

Interactive prototypes (high fidelity)

These prototypes complete the convergence process, with design teams now focusing on subtle interactions and nuances of the design. The interface is created by a tool or code that conveys the look and feel so that user scenarios can be perfected. Design flaws that were not possible to catch in the previous iterations are now exposed because the prototype truly reflects the final software product by simulating button clicks, navigation, and data entry.

Evaluating prototypes (alpha)

At this point, a full mockup or alpha version of the software has been created and is ready for more thorough testing using the following methods:

  • Competitive analysis techniques require a user group to test a new UI against existing UIs to understand what is desirable. This approach helps determine how the new UI stacks up against the competition. In this way, development teams are able to determine where a competitive advantage might exist.
  • Eye-tracking tests use sophisticated software tools to determine what users are gazing at within the UI and then what elements they interact with (link clicks, scrolling, etc.). The tool generates "heat maps," which show design elements that attract user interaction. Assumptions are replaced with real physiological data that reveals what users look at first, what they ignore, the root cause of usability issues, and, most importantly, how users intuitively learn the interface.

Once you have an alpha version of the software, you can do several different usability tests and surveys.  Here is a comprehensive list of UX surveys and tests, along with the advantages and disadvantages of each:

From the University of California, San Diego, HCI course. Click here for a larger image

What complexities do mobile apps introduce to UX design?

In November 2016, mobile Internet usage exceeded desktop usage for the first time. A user preference to receive information and conduct transactions on mobile devices has a complex impact on mobile UX design, most notably with screen size efficiency. There are only so many elements and actions that can be displayed on a screen before it becomes too confusing for users. Over 29% of smartphone users will immediately switch applications if it takes too long for them to find information. Some additional complexities that mobile apps introduce are:

  • Users interact with apps using their fingers and voice commands. According to a study published by UX Matters, 49% of users navigate apps with one hand. App workflows need to account for a type of interaction that is not typically found on desktop web apps.
  • The primary feature of a mobile device is to make phone calls. Designers have to consider the impact on usability of interrupts and gracefully transition app activities to the background.
  • Designers have to consider connectivity (Wi-Fi versus cellular network) and how to handle network performance that might impact usability. Developers can hide bad performance by making the app appear faster than it is.
  • Mobile screens limit the amount of useful real estate. Designers need to be efficient with the content they display. Mobile websites should be optimized or responsive. Each screen should provide one function or call to action for the user.
  • Device fragmentation forces designers to test on multiple hardware and operating systems to ensure that UX rendering is consistent across platforms. Apple and Google have different best practices for building apps for their platforms.
  • Other real-life conditions such as device memory consumption, battery life, and notification handling are additional scenarios UX designers need to account for in their planning. Over 50% of users find push notifications annoying and uninstall apps that do it.

The time-tested principles of UX haven’t changed

UX design considerations make applications competitive even in oversaturated markets. There are several options for prototyping an idea. Regardless of which prototype approach is chosen, they are all meant to go through several iterations, with the major task of incorporating real-user feedback. Mobile devices introduce new challenges but still rely on the heuristic principles of UX discipline. Particularly in the mobile space, feedback collected from potential users that are outside of the core development team is vital for vetting design theories and ideas.

Additional resources

While the core principles of UX design and testing don’t change for mobile applications, it’s important to learn as much as you can about the current trends, research, and heuristics being used to evaluate mobile today.  Here are a number of resources that will give you a 360-degree view of current mobile UX testing heuristics and trends.