The Laws of Interface Design
I need to open this post by apologising for the sporadic level of posts recently… Everything’s managed to catch up with me the last few weeks, leaving me with little time to blog or comment on all my usual daily reads. 
I’m off on my holidays tomorrow though - and I’m hoping to return to a more relaxed schedule!
Aaron Russell tagged me with this almost three weeks ago (has it really been that long?!?), and he was originally tagged by Marc Rapp - the creator of this fantastic meme. Aaron managed to weasel out of giving anybody any real advice though (only kidding mate), so I felt I should at least try to impart some pearls of wisdom! 
Several client projects this month have required me to do some GUI design - so I thought it might be appropriate to share some of the rules that I try to stick to when creating an interface. I think that these guidelines (learnt originally from a book by a guy called Shneider I believe) could be applied to both desktop and online applications - including websites!
Be Consistent
Sequences of actions in similar situations should be made consistent. Using identical terminology for menus, prompts and help screens will aid the user, as will the use of consistent commands throughout an application.
Reduce Memory Load
The level of information that our short-term memory can process is limited, so displays should be kept simple, multiple page displays should be consolidated where possible, and sufficient brain-training time should be considered for areas where codes, mnemonics and sequences of actions are introduced.
Feedback is Good
For every user action, there should be some sort of feedback reaction. Frequent or minor actions need only to result in a modest response, while the response of major or infrequent actions should be more substantial.
Utilise Simple Error Handling
A good interface or system is one that is designed so the user cannot make a serious error! If an error should be made then the interface should be able to recognise the error - offering simple and understandable mechanisms for it’s handling.
Frequent Users Like Shortcuts
As a user becomes more familiar with an interface, their desire to reduce the level (and pace) of interaction. Considered shortcuts, function key controls and macro facilities are all beneficial to an expert user.
Design to Yield Closure
Sequences of user actions should be organised into groups - with a beginning, a middle and an end. Good feedback upon the completion of these groups will gives users a satisfaction of accomplishment and indicate that they can proceed to the next action group.
Permit Reversal of Actions
A user’s anxiety about using a new interface will be greatly reduced by knowing that there is some sort of option to ‘undo’ their actions. Knowing that a mistake can be undone encourages the exploration of unfamiliar options.
I hope you found this useful, and I look forward to reading your comments or thoughts on other elements of interface design.
I’m going to tag these lucky people:
Tara @ Graphic Design Blog (you gotta do it if you’re tagged twice)
Lisa Sabin-Wilson (hope you’re OK!)
Damien @ Website Design Blog
Oh, and check out these other great posts for the same meme:
Marc Rapp @ Uniquely the Epitome : It’s the Law (at least for today)
Aaron @ miLienzo : What are the laws of design?
DT @ Design Sojurn : What are your Design Laws?
Jon Reil @ Another Day in Design : Ten Ways to Become a Better Designer
Mirko Humbert @ Designer Daily : Getting Rid of the Noise
David Airey : How Important are Laws of Design?
Asgeir Hoem : Laws & Principles of Design
Michael Surtees @ DesignNotes : Guidelines for Moi
Vivienne Quek @ Versa Creations : Are There Rules for the Creative Folks?
Calvin Warr : The Design Laws? Where’s The Fun in That?
Thanks to the following for their comments on my last post: Robyn, Paul B, resetblog, Tess, tomo, Zep and LaurenMarie.
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Thanks for the tag!
Very interesting post. I haven’t had any cases where application UI design was required, so I think I’d be a little error prone at first if it came up.
I think I’d come back to this post as a good starting point, though!
Glad you found it useful mate - nice to see that there are other people up as late as me! Must be an Essex thing…
I think the whole “user interface” thing can apply to pretty much everything that requires interaction from a user - be it a website, an application, a menu for a CD - whatever.
You’re a web designer and you made your blog, so you’ve already implemented UI design processes - even if you didn’t realise it at the time!
I look forward to reading your laws when I get back!
Hi Paul,
Hope Britster is going well.
Thanks for the tag (again) … I think
Paul,
Worthwhile reading this post - I definitely found it useful (I’ll try to read the others during the day!) but doesn’t it always boil down to the same thing?? K.I.S.S ??
Enjoy your hols!!
Good post, Paul.
Thanks for the mention … enjoy your holidays
Nice post! I particularly liked the 2nd last one: Design to yield closure. That each action should result in something would seem obvious enough… until you see some of “those” designs.
[…] Marc Rapp @ Uniquely the Epitome : It’s the Law (at least for today) Aaron @ miLienzo : What are the laws of design? DT @ Design Sojurn : What are your Design Laws? Jon Reil @ Another Day in Design : Ten Ways to Become a Better Designer Mirko Humbert @ Designer Daily : Getting Rid of the Noise David Airey : How Important are Laws of Design? Asgeir Hoem : Laws & Principles of Design Michael Surtees @ DesignNotes : Guidelines for Moi Vivienne Quek @ Versa Creations : Are There Rules for the Creative Folks? Paul Enderson : The Laws of Interface Design […]
[…] being tagged by graphic designer Paul Enderson in his excellent article on interface design, I thought I’d take a slightly different approach and put together a short article on the […]
wow. really great stuff here. awesome. ( yes, I used the word; awesome )
Marc
Good stuff Paul. I totally agree about consistency in menus, etc. I read somewhere that you should even try to keep navigation items consistent when it comes to using one or two words. Did I say that right? For example, all nav elements should have either one word or two but not a mix of both. I wish I could remember who suggested that.
The Closure thing I was not familiar with, but it makes sense. I’ve not had any formal experience in designing app interfaces, so this was a good brief for me should I ever wander into that realm.
Reversal and Closure are two big issues for the stuff we run in our environments. Most of the apps are cut from a similar engine and they all have the habit of circulating back into heavily loaded options screens and the status prompts are vague. Drives people completely nuts. Because of the way they all run as well, most changes are permanent as soon as they are initiated, at the worst case leaving orphaned or partially completed transactions.
If only the meme existed three years ago it might all be somewhat cleaner. =P
I’m surprised no one has specifically mentioned keeping link colors consistent and having the a:visited tag be a different color than the non-visited links (Nielson’s Alertbox article, if you’re interested). It was also our friend Jakob Nielsen who noted, “Users spend most of their time on other sites.” Don’t try to be too clever, it will only confuse people.
[…] The Laws of Interface Design Paul Enderson covers several rules that he tries to stick while working on interface design. […]
Those are all very good principles to practice during development. I have found HTML microformats beneficial for my development, reinforces the consistency rule.
Tara,
Britster’s getting there! We’ll be launching on September 1st, so expect to see all the niggles you helped to find start getting fixed!
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Aaron,
Ah… Playing Yoda card not always get out clause is. Glad you found it useful mate!
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Vivienne,
My pleasure - yours was an interesting read!
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Calvin,
Thanks for your comment - and the ping! Glad you enjoyed my contribution.
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Marc,
Thanks for the great meme in the first place!
It’s awesome that you think it’s awesome… 
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Charity,
Your bang on with the consistent menu text. I always used to end up arguing with clients over that one - being asked for ‘Home’ to be put next to ‘Advanced Management Techniques for the Marketplace’ for example!
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Brad,
Sometimes legacy systems force users to perform illogical actions - and there’s typically no way of resolving this without a total recode. Most of the Micro$oft Office suite springs to mind as a good example of this!
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LaurenMarie,
That’s another good point. I guess it could be included under the ‘be consistent’ banner - but not trying to be too clever (the KISS principle) is definitely an art that seems to be ignored by many interface designers. If you ever get the chance then take a look at the Traktor range of software by Native Instruments - a DJing application has never looked so cluttered!
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Matt,
Thanks for your comment!
We’ve still to see Microformats have their 15 minutes (hopefully longer) of fame… It’s something that I can see happening as all the legacy chunks of the web are replaced by semantic systems.
Thanks for the mention Paul, and nice post! What I like about this meme is the flexibility of the topic. There was even a copy writer posting his tips, which is found at http://walterburek.info/?p=136 .
Thanks Asgeir! This is certainly one of the most flexible memes I’ve been involved in.
Walter’s response is a good one, and it’s nice to see that the meme has spread outside of the typical boundaries of creativity too!
Hola! Shoot me an email when you have some time. I’m gathering the rest of the meme and will need to organize credits/titles etc.