Icons, their Cognitive Effect and Scientific References

Question

As part of may daily intake of UX vitamins, I was questioning myself the following. We use pretty much icons in our everday activities. We use them on computers or in cereal boxes, and we expect them to exist and be located in certain places on the object we're using.

From Recycling Icons on paper cups, to on/off icons on screens or computers, to Microsoft word documents, they're everywhere.

However, an Application I'm working on, doesn't use them that much.

I wanted to know: what are the positive/negative cognitive effect of icons from Scientific Sources, like:

• Decreased time-to-action or
• how comfortable they make new users feel.

I couldn't find any source on this specific item. I think we are so used to them, that we don't question them as much as we should.

The papers I stumbled upon are listed below, however, I don't think they quite cover the questions above.

• Microsoft Windows | Dev Center: Standard Icons
• Microsoft Windows | Dev Center: Icons
• User-Computer Interaction: Cognitive Properties of Icons for Multdimensional Data Analysis
• Cognitive Modelling of Icon Comprehension
• Cognitive Principles of Graphic Displays
• Structured Data Analysis: A Cognition-Based Design for Data Analysis Software

Answer 1

From the very useful reading list which Apple used to provide with their developer guide (takes a while to load up from the wayback machine).

Obviously the use of icons (& psychology of them) predates their usage on computers:

( Whether these publications are still available is another matter ! )

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Icons and Symbols

• Diethelm, Walter. Signet Sign Symbol. Zürich: ABC Verlag, 1976.

• Dreyfuss, Henry. Symbol Sourcebook: An Authoritative Guide to International Graphic Symbols. New York: Van Nostrand Reinhold, 1984.

Presents thousands of symbols, presented first by subject, then by shape, and finally in the index by name. This book provides a fertile source for the designer seeking icons or other stylized design images.

• Frutiger, Adrian. Signs and Symbols: Their Design and Meaning. New York: Van inhold, 1989.

• Holmes, Nigel, with Rose DeNeve. Designing Pictorial Symbols. New York: Watson-Guptil, 1985.

Presents 54 case studies of how concepts were transformed into icons. This book is useful because it not only shows the finished icon but also explains the stages and thoughts that the designer went through to create each icon.

• Modley, Rudolf. Handbook of Pictorial Symbols. New York: Dover Publications, 1976.

• Wildbur, Peter. Information Graphics. New York: Van Nostrand Reinhold, 1989.

Answer 2

The use of icons is a fairly discussed issue here on UX.SE. I would suggest you read the answer from Michael Zuschlag in this post where he breaks down the problem very thoroughly.

Not having any scientific data to back me up I would still say that there are cases when the use of icons are much more usable than descriptive text. And I'm not talking about the floppy disk icon for Save. Although that is a recognized pictogram for the action Save, it doesn't really touch the cases I want to discuss.

Icons are a great tool when the icon itself helps the user understand its meaning better than a descriptive text would. A perfect example of this is the use of icons to represent the styling/formatting of text in text editors.

As far as I'm concerned these three icons do a much better job than three buttons saying

^{download bmml source – Wireframes created with Balsamiq Mockups}

So why are they better? Well, the icons clearly show what will happen to the text when the user triggers them, in a way that the descriptive text doesn't. This will reduce the cognitive load as the user won't have to scan the GUI and translate the semantic meaning of the terms, the icon does it for them!

In addition to this the users that are unaware of the English terms for these options will find much aid in finding the correct action using the icons, and thereby having the cognitive load and time form trial and error reduced.

There is generally, in my mind, a too much "that will do" mindset when choosing an icon over descriptive text. The justification according to the designer is that the GUI will "look better" and "be more streamlined". This is however purely a graphic designer/artist approach and will in most cases not be suitable usability wise.

A good example is this post where the OP wants to find an icon that describes Factory reset instead of using the descriptive words "Factory reset". Where the most popular answer provided is:

And sure, when playing Pictionary this illustration would be very nifty and some of the contenders would probably get it (I must admit I would struggle with it though). But were not playing Pictionary, are we... And Roger, the answerer, clearly states that the icon should be combined with clear labelling that clarifies that "This icon represents the action Factory reset". Rendering the icon redundant.

In summary, use icons when you can clearly justify that the icon will convey the action more clearly than a descriptive text will.

Answer 3

"A picture is worth more that 1k words". IMO, icon can be associated much more quickly with appropriate action that a set of letters in a word or sentence.