Usability is a measure of the quality of a user's experience when interacting with a website, people have been focusing on website usability since the explosion of the world wide web in the 1990's, but it is unfortunately an aspect that is frequently overlooked when it comes to eCommerce site design.

The increasing availability of shopping cart software has lead to an increase in the number of people launching internet stores, many of these people are inexperience with advanced web design techniques and theories and many more purchase cheap design work that doesn't focus on what the store customer's wants and needs. What the customer wants from an online store is to be able to find and purchase the products that they want as easily and quickly as possible.

When a customer visits your site it is more than likely, if your marketing has been successful, that they wish to purchase a product from you. As a store owner you need to remove every possible barrier between them arriving to your site and completing your purchase, the more barriers you make your customers climb over the more likely they are to run off your competitors.

This article contains will focus on a number of areas of usability and how to apply them to your eCommerce store, there are many many areas of usability that need to be considered when designing an eCommerce store and this article could be multiple pages long but we are going to focus on four factors that we feel are the most important. These areas are navigation, searches, validation and checkout.

The Navigation that you implement on your site is probably the most important aspect of usability, if your visitors cannot find their way around your site your dead in the water. It is imperative that you make sure your navigation is clear, simple and in a prominent place on your pages. Although navigation is an area that is normally implement quit well in eCommerce solutions where they normally fall down is their user of markers to make sure the user knows where about in the store they are, if they get lost and cannot find their way out they are going to get frustrated. There is a number of very well tested web design standard to get round this issue. Category tabs, dynamic menus and breadcrumb trails all help your customer find their way around your site.

If a customer lands on your front page and cannot immediately see where the product they want will be more surfers initial actions it to reach for the search box so make sure that your search box is obvious and easily accessible. The other area of your sites search facility you need to pay attention to is the results it is important to make sure that your customers are getting the right results when they do find the search box. It is normally a good idea to 'adjust' the search results on internet stores to allow customer to be presented with the products they're looking for.

Making sure your site validates against the W3C Standards is important. Making sure your site follows CSS and XHTML/HTML guidelines will make sure your sites appearance is replicated accurately across different types of web browsers, non-valid pages have their errors corrected by the browser, how this works varies radically across different browsers (and even different version of the same browser).

In order to minimise shopping cart abandonment the usability of the Checkout component of your shopping cart software is important. There are a number of important steps to take to make sure your checkout process is as usable as possible.

- Make sure your checkout is as short as possible, people get bored quickly on the internet

- Don't ask for any information you don't need, people are weary of giving away personal information

- Remove all distraction from the checkout, if they click away from the purchase they might never come back. This includes removing any unnecessary internal site navigation

There are many more aspects of usability you will need to consider when looking for shopping cart software but these should get you started in the right direction.