What is Lostness in IA (Information Architecture)?

Summary: Lostness is a metric which helps you to understand the how lost your users are when they use your product and here you will learn how to calculate Losteness value effectively.

Assume you and your friends went on a forest adventure, and you’re all having a great time until you realize you’re lost. There’s no electricity, no mobile networks, and you don’t even have a map. What would you do? What would be your’s reaction?

You can pretty much guess what I’m talking about.

The reaction could be like

The same thing could happen in websites or applications also if user interacting with the website like the below examples;

I understand there are many issues with the user experience and the aesthetics, but if we just focus on the findability of this website, I feel it will be difficult for a user to find the specific item.

What do you think?

That is why we measure the Lostness value in the User Experience area.

What is this?

Lostness is a metric that helps you understand how lost your users are when they use your product (like website/applications). [Smith 1996]

Formula:

Lostness formula

L= Lostness.

N= The number of different web pages visited while performing the task.

S= The number of total webpage/screens visited while performing the task. (it could revisit the same webpages also)

R= The minimum (optimum/Ideal) number of pages that must be visited to complete a task.

Please note:

•It could be measure through pages or tabs or taps or clicks or swipes. As long as you’re consistent with what you measure.

•If the Lostness score should be under or equal to 0.4, it indicates that there are not lost (L< = 0.4).

• The lostness measure ranges from 0 (absence of lostness) to 1 (being completely lost).

Let’s understand how to measure Looseness with an example:

She is Jane Doe, a freelance fashion designer, and she is looking for a Red small size t-shirt for her daughter, so she goes to the well-known website www.xyx.com(dummy website) to look for it. After much struggle, she eventually found it, but let’s look at her entire journey flow to see how she interacted with it.

Miss Jane Doe landed on this website(Home) and she is looking for an item that is available on page B3(orange color page/Page B3).

This is the optimal number of steps(R) required in order to find the item.

This is the actual number of steps(S) she took to find the item.

Now R=3, N=7, S=10, and you need to figure out L=?

So, as shown below, we’ll use the above-mentioned formula to calculate the value of L.

We calculated the value of L which is 0.65, step by step, and it’s greater than 0.4 so we can say that she is lost on this website while she was looking for that item.

It’s tough to calculate everything using the above formula if you have a lot of test tasks and many users for your research, hence I’m sharing the spreadsheet below to calculate lostness effectively.

This is a screenshot of the example for Measuring Lostness; you could measure lostness for both your Participants and your Task, and the graph will show you which one has the highest value of looseness and where you should focus more.

Here you will find the template to calculate the lostness, in order to use it please make a copy and save it in your system, and based on your research requirements you can customize this template.

Click here for Google sheets - create and edit spreadsheets online,

So, now that you know how to calculate the looseness value for your product, I advise combining this metric (L) with some other metrics during usability testing so that you can gather rich data to better understand the problem areas.

Best wishes and please don’t hesitate to contact me if you have any questions.

Please applaud if you like it.

Thank you :)

References and where to learn more

Validating a Lostness Measure

Lost in Learning: Hypertext Navigational Efficiency Measures Are Valid for Predicting Learning in…

[PDF] Implicit measures of lostness and success in web navigation | Semantic Scholar