How to measure information overload of an UI?

Question

I would like to measure the "information overload rate" of an UI.

It's important to note that I'm searching more for a questionnaire / analysis which evaluates the information overload implicitly or by defined quantitative properties, not by asking the user explicitly about their perception of information overload.

Does anyone know a established scientific questionnaire / survey / analysis method to do so?

Many thanks!

Answer 1

I suggest you use the System Usability Scale.

This is a 10-question, Likert-scale survey used to measure respondents' assessment of the usability of any system.

The survey does not explicitly ask about "information overload", but its questions address related concepts:

On a scale of 1 to 5, where 1 = strongly agree and 5 = strongly disagree

• I think that I would like to use this system frequently.
• I found the system unnecessarily complex.
• I thought the system was easy to use.
• I think that I would need the support of a technical person to be able to use this system.
• I found the various functions in this system were well integrated.
• I thought there was too much inconsistency in this system.
• I would imagine that most people would learn to use this system very quickly.
• I found the system very cumbersome to use.
• I felt very confident using the system.
• I needed to learn a lot of things before I could get going with this system.

The aim of the survey is to produce a single score -- a benchmark -- that can be compared with scores produced by other other users of the same system, or of other systems.

Answer 2

Sounds like leveraging a tool like the Five Second Test from UsabilityHub could be useful here.

We show your design to people for five seconds. When the time is up they're asked questions about what they remembered.

There is also Chalkmark from Optimal Workshop.

Reveal first impressions of designs and screenshots

Answer 3

A simple and very often used method would be the Likert scale a.k.a 1-5 scale. This would be useful for explicitly measuring the cognitive load of a set of UIs. This option is cheap and easy to implement.

From your comment, you seem to prefer to take implicit and quantitative measurements. Unfortunately these are a little less accessible, more expensive and more difficult to implement, and arguably inaccurate barring a full blown neuroimaging brain scan.

Nonetheless I will give you two methods that I know.

1. Task-invoked pupillary response - By hacking some eye-wear you would be able to measure the eye response. Unfortunately every bodies eyes are quite different (especially age ranges) and so person-to-person comparisons are difficult.
2. Tap Test - by making the participants tap once every second whilst using the product.

Answer 4

As well as the qualitative approaches already mentioned, you might want to try something quantitative, like time to complete task. Ask the user to do something with the UI and time how long they take to achieve it.