What is the importance of consistency in the design of webpages?

Answer 1

Web design is about making the user feel comfortable on your page. It really should be called "web usability". Because the goal is to keep the user on the page as long as possible. For that they need to feel comfortable browsing your site.

Which means even though you can be creative, a good site design should follow some consistency and conventions. There are certain conventions they already are familiar with from browsing the large sites like Yahoo, Google, etc...

e.g.
menu bar on the left or on the top
functions on the right usually (log in, log out, search, etc)
content usually in the middle/bottom below the logo
logo is a link back to the home page
several links on the bottom like "About" "Careers" "Contact Us" ..etc.

Answer 2

Consistency in web site design is important because your users are idiots.

OK. Maybe you're the lucky one who happens to have users who are all Mensa members. A the very least, your users are lazy.

As designers, there's a myth that permeates the industry: users read web pages. They don't. Because of the ease of correcting a mistaken click (just hit "back") users instead satisfice. They simply look over the page, and click the first thing that seems right.

If you start to change the layout of pages, then users have to pause and think about what they're going to do next. As a rule, users don't like this. If your site is harder to use than your competitors, then your users will head off to your competitors.

Think about automobiles. They all have extremely similar user interfaces. That's because no one wants a car that forces them to learn how to drive again. There are some basic rules (steering wheel, gas pedal on the right, shift either to the right or on the steering column, etc) for the designers who layout the insides.

The same applies to web designers. Menus, as a rule, go on the top of the page, or on the left (except in some languages that read right to left, in which case those menus tend to be on the right.) More important things are bigger. The if both the top and the side are going to have a menu, then the side menu has the localized navigation, and the top menu has the top level navigation.

You can break these rules, but you'd better have a darn good reason to do it. And whatever you're getting by breaking them better make up for me, as a user, having to figure out what weird thing you did.

In the end, the message is still simple: if you're site is hard to use, no one will use it. Google makes it easy to find something easier. So don't make me think.