When it comes to improving usability and the overall user experience, we must start by focusing on navigation and information architecture. Ensuring that tasks are not only easy but also efficient for users to complete. This means creating a seamless navigation experience, allowing users to effortlessly find their way through the product while maintaining a clear sense of their position within the structure.

What is Lostness?

One widely recognized method for measuring the effectiveness of navigation and information architecture is through the use of an efficiency metric known as "Lostness." Lostness essentially quantifies how many steps a user needs to take to successfully complete a task.

Score

The Lostness metric is calculated as the average lostness of all respondents who successfully completed the task. It operates on a scale where a high Lostness score, closer to 1, indicates that users are feeling disoriented and struggling to navigate through the task. Conversely, a low score, closer to 0, suggests that users can complete the task with relative ease.

One way of looking at the lostness score is to adopt a 0.4 score as a critical mark. If the L Score is greater than 0.4 we can say that a user was lost while performing a task.

Formula

• L (Lostness): Represents the Lostness score.

• N (Number of Screens Visited): Count of different (unique) screens users visited during the task.

• S (Total Number of Screens): Total number of screens users visited during the task.

• R (Minimum Screens Required): Minimum number of screens that must be visited to successfully complete a task.

This metric provides valuable insights into the user's journey within the product, helping us understand the difficulties they face. But it's very difficult to calculate a score for each participant if you have more than a few, it's just unpractical and time-consuming. That's why I created a "Lostness" Google Sheets Template to make it easier for you to focus on what's really important here instead of wasting time crunching numbers over and over for each participant in the test.

Example

To understand the concept of the Lostness metric even better we should look at the example.

In the picture above we can see the structure of a simple mobile application.

The minimum required steps/screens (R) to take in order to complete the task is 3. The user needs to go to Home > B > B1.

What the user actually did on the test was go to Home > A > A1 > A1.1 > A1 > A > Home > B > B2 > B > B1. This means that the user made 11 steps in total (S), and 7 unique steps/screens (N).

Template

Feel free to try out a highly efficient Google Sheets Template for Lostness Metric Study, it is available for free in my Store section, with the aim of simplifying usability analysis and saving valuable time.

This user-friendly template requires minimal effort, all you need to do is input your data from your next usability study. It automatically applies the necessary formulas and conducts all crucial calculations, even generating a visual chart for you.

Summary

By using Lostness, UX researchers and designers gain a quantitative measure of user navigation and information architecture efficiency. This allows us to pinpoint areas where improvements are needed and craft more user-friendly interfaces that reduce the sense of "being lost" within a digital landscape. So, when it comes to enhancing UX, understanding and optimizing Lostness can be a powerful tool in our arsenal.