Top 5 usability and design principles in web site development
Many clients I work with today have come from a wealth of experience in other media formats, be it the big screen or traditional print. They often bring with them a pre-conceived notion of how they want things to look and work on the site. Quite often it is a direct translation of their existing media strategies and they want to keep the content and format consistent for the sake of 'branding'. The web however is a fundamentally different beast than most mediums due to both the way the user interacts with it and the immensely broad reach. So a slightly different approach is needed. Pay attention to these things, and you'll ultimately end up with a happier audience and happier clients.
Users want instant gratification
There is nothing worse than clicking a link and waiting 10 seconds for a response. Back in the early days this was the norm, but now that content is delivered near instantly an expectation is set. Don't make them endure a long download just to show them a doorway flash page into your site, or some new animated navigation bar. Likewise with operations you now may take a while to process such as a search or uploading and processing of data. Where possible, push long running operations into a background process if the user doesn't need to immediately see the results. Where they do, provide the illusion of a partial instant response with a progress indicator
3 it's the magic (click) number
(... with apologies to schoolhouse rock). An old one from back in the day that still holds up in some regards today. And even for those naysayers that believe things are different, I've not heard a valid reason as to why should strive to meet this objective so long as it doesn't conflict with any others listed here. That is, make sure that whatever the user wants to do or find is never more than 3 clicks away. Beyond that point you run the risk of the user becoming frustrated and using that little Google search box in the top of their browser to find somewhere other than your site to get what they want.
And think about it, if you're using a traditional desktop application how often do you need more than 3 clicks to do anything within it? Menu bar > Option > Tool panel. File > Open > Select File. And online? Go to Amazon > Find Book > 1-click order.
It won't always be possible with absolutely every site, but you should try and make most adhere to it.
Make sure your elements Fitts
Fitts's Law is from the wikipedia article: "a model of human movement which predicts the time required to rapidly move to a target area, as a function of the distance to the target and the size of the target'. Basically what that means is that the bigger and more obvious you can make the areas you want someone to click, the easier it will be. Seems obvious right? Take a read through this quiz over at AskTog for some insight into how what otherwise seems like common-sense, isn't that sensible at all. Suffice to say, you really need to pay more attention to when you place a 'buffer zone' around your objects, and when you flush things hard against the screen.
Make it as simple as possible, and no simpler
Psychological studies have raised a theory that the human brain is usually only capable of handling around 7 pieces of stimulus at a time. If you are wanting to maximise reader engagement, or improve your click through rates, the best thing to do is reduce the number of options they have to deal with at any given point in time. That goes for navigation, filling in forms, etc. Start pushing past 10 items unless it's absolutely needed or expected and you starting walking the fine line to sensory overload.
Summarise your content
This fits in nicely with the expectation of instant gratification. Meaningful headlines and a first paragraph that acts almost like a conclusion or executive summary, giving the outcome of the following text allows the user to quickly determine if the content is appropriate. At the end of the day, you don't want to falsely lure users into sections they won't find relevant.