Best Practices & Principles for GUI design

Question

What is your best practical user-friendly user-interface design or principle?

Please submit those practices that you find actually makes things really useful - no matter what - if it works for your users, share it!

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Summary/Collation

Principles

1. KISS.
2. Be Clear and Specific in what an option will achieve: e.g.: use verbs that indicate the action that will follow on a choice (see: Impl. 1).
3. Use obvious default actions appropriate to what the user needs/wants to achieve.
4. Fit the Appearance and Behavior of the UI to the environment/process/audience: stand-alone application, web-page, portable, scientific analysis, flash-game, professionals/children, ...
5. Reduce the learning curve of a new user.
6. Rather than disabling or hiding options, consider giving a helpful message where the user can have alternatives, but only where those alternatives exist. If no alternatives are available, its better to disable the option - which visually then states that the option is not available - do not hide the unavailable options, rather explain in a mouse-over popup why it is disabled.
7. Stay consistent and conform to practices, and placement of controls, as is implemented in widely-used successful applications.
8. Lead the expectations of the user and let your program behave according to those expectations.
9. Stick to the vocabulary and knowledge of the user and do not use programmer/implementation terminology.
10. Follow basic design principles: Contrast(Obviousness), Repetition(Consistency), Alignment(Appearance), Proximity(Grouping).

Implementation

1. (See answer by paiNie) "Try to use verbs in your dialog boxes."
2. Allow/implement Undo/Redo.

References

1. Windows Vista User Experience Guidelines [http://msdn.microsoft.com/en-us/library/aa511258.aspx]
2. Dutch websites - "Drempelvrij" guidelines [http://www.drempelvrij.nl/richtlijnen]
3. Web Content Accessibility Guidelines (WCAG 1.0) [http://www.w3.org/TR/WCAG10/]
4. Consistence [http://www.amazon.com/Design-Everyday-Things-Donald-Norman/dp/0385267746]
5. Don't make me Think [http://www.amazon.com/Dont-Make-Me-Think-Usability/dp/0321344758/ref=pdbbssr_1?ie=UTF8&s=books&qid=1221726383&sr=8-1]
6. Be powerful and simple [http://msdn.microsoft.com/en-us/library/aa511332.aspx]
7. Gestalt design laws [http://www.squidoo.com/gestaltlaws]

Answer 1

(Stolen from Joel :o) )

Don't disable/remove options - rather give a helpful message when the user click/select it.

Answer 2

Related question: http://stackoverflow.com/questions/51050/what-are-some-good-usability-guidelines-an-average-developer-should-follow

Answer 3

I try to adapt to the environment.

When developing for an Windows application, I use the Windows Vista User Experience Guidelines but when I'm developing an web application I use the appropriate guidelines, because I develop Dutch websites I use the "Drempelvrij" guidelines which are based on the Web Content Accessibility Guidelines (WCAG 1.0) by the World Wide Web Consortium (W3C).

The reason I do this is to reduce the learning curve of a new user.

Answer 4

I would recommend to get a good solid understanding of GUI design is to read the following book. Although the main printable is a comment from JOEL: When the behavior of the application differs to what the user expects to happen then you have a problem with your graphical user interface.

Best example is, when somebody swaps around the OK|Cancel button on some web sites. The user expects the OK button to be on the left, and the cancel button to be on the right. So in short, when the application behavior differs to what the user expects what to happen then you have a user interface design problem.

URL: http://www.amazon.com/Design-Everyday-Things-Donald-Norman/dp/0385267746

Although, the best advice in no matter what design or design pattern you follow is to keep the design and conventions consistent throughout the application.

Answer 5

As my Data Structure professor pointed today: Give instructions on what your program works to the average user, we programmers often think we're pretty logical with our programs, but the average user probably won't know what to do

Answer 6

If you're doing anything for the web, or any front-facing software application for that matter, you really owe it to yourself to read...

Don't make me think - Steve Krug

Answer 7

Try to think about what your user wants to achieve instead of what the requirements are.

The user will enter your system and use it to achieve a goal. When you open up calc you need to make a simple fast calculation 90% of the time so that's why by default it is set to simple mode.

So don't think about what the application must do but think about the user which will be doing it, probably bored, and try to design based on what his intentions are, try to make his life easier.

Answer 8

The Design of Everyday Things - Donald Norman

A canon of design lore and the basis of many HCI courses at universities around the world. You won't design a great GUI in five minutes with a few comments from a web forum, but some principles will get your thinking pointed the right way.

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MC

Answer 9

Breadcrumbs in webapps:
Tell -> The -> User -> Where -> She -> Is in the system

This is pretty hard to do in "dynamic" systems with multiple paths to the same data, but it often helps navigate the system.

Answer 10

Avoid asking the user to make choices whenever you can (i.e. don't create a fork with a configuration dialog!)

For every option and every message box, ask yourself: can I instead come up with some reasonable default behavior that

• makes sense?
• does not get in the user's way?
• is easy enough to learn that it costs little to the user that I impose this on him?

I can use my Palm handheld as an example: the settings are really minimalistic, and I'm quite happy with that. The basic applications are well designed enough that I can simply use them without feeling the need for tweaking. Ok, there are some things I can't do, and in fact I sort of had to adapt myself to the tool (instead of the opposite), but in the end this really makes my life easier.

This website is another example: you can't configure anything, and yet I find it really nice to use.

Reasonable defaults can be hard to figure out, and simple usability tests can provide a lot of clues to help you with that.

Answer 11

Show the interface to a sample of users. Ask them to perform a typical task. Watch for their mistakes. Listen to their comments. Make changes and repeat.

Answer 12

Be Powerful and Simple

Oh, and hire a designer / learn design skills. :)

Answer 13

Never ask "Are you sure?". Just allow unlimited, reliable undo/redo.

Answer 14

Follow basic design principles

• Contrast - Make things that are different look different
• Repetition - Repeat the same style in a screen and for other screens
• Alignment - Line screen elements up! Yes, that includes text, images, controls and labels.
• Proximity - Group related elements together. A set of input fields to enter an address should be grouped together and be distinct from the group of input fields to enter credit card info. This is basic Gestalt Design Laws.

Answer 15

Summary/Collation

(Moved to Question and changed to community wiki)

Answer 16

When constructing error messages make the error message be the answers to these 3 questions (in that order):

1. What happened?

2. Why did it happen?

3. What can be done about it?

This is from "Human Interface Guidelines: The Apple Desktop Interface" (1987, ISBN 0-201-17753-6), but it can be used for any error message anywhere. There is an updated version for Mac OS X. The Microsoft page User Interface Messages says the same thing: "... in the case of an error message, you should include the issue, the cause, and the user action to correct the problem."

Also include any information that is known by the program, not just some fixed string. E.g. for the "Why did it happen" part of the error message use "Raw spectrum file L:\refDataForMascotParser\TripleEncoding\Q1LCMS190203_01Doub leArg.wiff does not exist" instead of just "File does not exist".

Contrast this with the infamous error message: "An error happend.".

Answer 17

I test my GUI against my grandma.