There's a truism that says, "beauty is in the eye of the beholder."    I'm here to tell you that that's not precisely the case; that the quality of beauty is not subjective.  Beauty is clearly definable, and universally understandable. You look at a person, a picture, or a user interface UI), and you can quickly  tell if it looks good or not.  With just a little bit of instruction, you an come to understand exactly why it looks good or not.

The 30,000' view is that it is so because the idea of what things (or people) generally look pretty has been long arrived at by consensus.  And somewhat scientifically; by which I mean using metrics that can be reproduced.  Images are good example of this. Photographs and paintings which follow the rule of thirds simply look more pleasing than those which don't. 

There's a rule for people, too. Taken as a whole, folks we look at are considered pretty if their faces and bodies are symmetrical.  Where each arm hangs at the same length and angle as its twin, and never below the knees. Where each eye is a mirror of its opposite. Where the nose is neither too large or too small (IOW, too long or too wide) when proportioned with the area running up and down between the hairline and jaw line, and left to right between each ear.  Speaking of which, it's generally agreed that ideally the ears should also be somewhere between 8% and 12% of the height of the face, not sticking out by more than 23% of individual height, and that no more than 2/5 the distance from the crest of the ear measured to its lobe.

Really...you could go look it up.

My point is, if you look close enough you can tell the difference between someone who looks okay (like me from a distance) or my good friend Waz, who looks good enough from any distance to be able to star in movies.  It's a matter of the symmetry of the whole.  You can tell the same thing with picture on a wall or a UI staring up from your laptop.

Recognizing a Good User Interface

When you look closely at a UI to be able to analyze it, you're basically taking in three factors, whether or not you realize it at the time: your perception of the UI, how well it resonates with you cognitively, and how easy it is for you to use.

Perception has too to do with the overall look of the UI.  How well its colors go together and how well you can read text falling anywhere on the  page.  And how quickly you can pick out from the whole a single element to notice.  If you can pick that element out in less than 200 milliseconds, then it's considered preattentive, and that's a good thing.

Cognition has to do with how understandably the UI conveys its information to you.  Can you quickly integrate its messages, reason through them, and unambiguously comprehend their meaning?  Is the data with which you are presented organized and displayed well enough that you can quickly turn it in your mind into information?

Usability has to do with how well you are able communicate with and manipulate the application underlying the UI.  For example, is it consistent; does everything work the same way...or at least as you would expect them to?  We all make mistakes.  So one very important part of an application's usability is whether the feedback you get from dialog boxes and error message clear and valuable in guiding you away from similar errors in the future?  And for those times when you really mess up, how cleanly does the application recover from the error?

Well...I think that's enough for now.  In upcoming blogs, I'm going to give you a list of ten specific items you can use as a checklist to unambiguously know how good is the UI you are analyzing.