Learn more about KPIs in UX Design

Imagine your new manager swings by your desk and asks, “How did the research study you conducted last week go?” How would you respond? Any time you conduct research, you want to have a way to measure the effectiveness of your product or prototype. To do so, use key performance indicators (KPIs), which are critical measures of progress toward an end goal. As you might remember, KPIs are the fourth element in a research plan, and you’ll often be asked about your KPIs as a UX designer in the real world.?

There are many KPIs that can be useful when planning and conducting a UX research study. You were introduced to six KPIs in the video, so we’re going to dive deeper into those six and explore an additional seventh KPI to consider.?Let's get going!

Time on task measures how long it takes for a user to complete a task. A task can involve any function within the product you’re designing, such as filling out a form or making a purchase.?

To measure time on task, all you need is a timer! Start timing the user when they begin the task you’ve assigned, and stop timing as soon as they completed the task. For example, you might time how long it takes for a user to start from the home screen of your app and complete the checkout flow to purchase a shirt. It’s generally safe to assume that the less time it takes for users to perform a task, the more effective your design is.

Use of navigation vs. search indicates the number of people who use a website or an app’s navigation, compared to the number of people who use the search functionality. In other words, some users will prefer to use the navigation bar to get around your product, while others will go straight to the search bar, type in a query, and be directed to part of the product.

To measure use of navigation vs. search, count the mouse clicks or taps on navigation-related parts of your design, and compare that to the number of times a query is entered into the search bar. This KPI, unlike most of the others, measures the preference of users, instead of whether something is “good” or “bad,” so you don’t need to worry if the numbers are high or low. Instead, the goal is to help you understand how users interact with the navigation and search functions of your product. Keeping track of your users’ preferences can help you strike a good balance between them in your designs.

User error rates indicate the parts of a design that cause users to make errors. For example, a user might click on the wrong icon when trying to make a purchase, forget to check a box, or submit incorrect information when filling out a form. These errors are not the user’s fault! Instead, user error rates help point to areas where you need to make improvements to the design of the user experience.?

To measure user error rates during a research study, keep track of the parts of your design where users make mistakes when completing the tasks you’ve assigned. As a general rule, the lower the number of errors, the better the design.

Drop-off rates show how many users abandon the experience. In other words, this KPI reveals how many users quit before reaching the end of a purchase or some other endpoint you’re trying to lead them to. Users might quit using your product if the navigation is difficult to understand, if they get frustrated while trying to complete a task, or if they simply get bored.?

To measure drop-off rates in your own designs, count the number of participants who quit a task or don’t make it to the end of their goal. Then, make changes to your designs to improve the user experience and run a second research study. You can compare the drop-off rates from each study to measure the success of the design changes. Your goal is to decrease drop-off rates with each design iteration.

Conversion rates measure the percentage of users who complete a desired action. Conversion rates are the opposite of drop-off rates. Any time a user successfully completes a task, meets a goal, or makes it to the final destination of your product, it’s a conversion. Think of the dog walker app as an example: The user needs to take multiple steps to find and reserve a dog walker. The conversion rate will show the percentage of users that actually made it to the end of the flow and booked a reservation.?

To measure the conversion rate for your product, count the number of research study participants who complete a listed action. As a general rule, the higher the conversion rate, the better the design. In addition, comparing the conversion rate from one research study to the next can help you gauge the success of the changes you made to your designs.

A System Usability Scale (SUS) is a questionnaire that asks participants their opinions about your product; the results are used to measure the usability of your designs. In an SUS, users are asked the extent to which they agree or disagree with 10 statements about the usability of a design. For example, users might be asked to respond to the statement: “I thought the app was easy to use” on a scale from “strongly disagree” to “strongly agree.” It’s a quick and reliable way to know if a design is working.

You can use a SUS to measure the usability of your own designs! You want participants to “strongly agree” with positive statements (such as “I thought the app was easy to use”) and “strongly disagree” with the negative statements (such as “I found the design unnecessarily complex”). You can also calculate an overall score for your design based on the survey responses.

The Net Promoter Score (NPS) is a measure of how loyal users will be to your product or service. The NPS measures the likelihood that a user would recommend your product to a friend or colleague. Participants rate the question, “Would you recommend this product to a friend or colleague?” on a scale of 0 to 10.?

• Promoters are participants who give a rating of 9 or 10, which means they would recommend your product to others.?
• Passives are participants who give a rating of 7 or 8, which means they are satisfied with your product, but they probably won’t pass it along to friends or colleagues.?
• Detractors are participants who rate from 0 to 6, which means they could warn people away from your product or service.?

To calculate the NPS, subtract the percentage of detractors from the percentage of promoters. When your NPS is positive, it’s a sign that users are satisfied with your designs. Well done! You want your NPS to be a high positive number. If your NPS is negative, it’s a sign that your user experience might have bugs, be difficult to navigate, or might otherwise cause frustration among users.

Choosing KPIs?

These seven KPIs are important measures of success for your research study and for the designs you're testing. When deciding which KPIs to measure for your project, think about the goals of your research and the findings you want to be able to present to your team, or include in your portfolio, after the research concludes. Each KPI is unique, and together, they work to help you measure the success of the user experience you’ve designed.