RE: E-Commerce Design Patterns

A very interesting discussion and one in which I'm sure there'll be much more debate.

Having developed software applications for a number of platforms and also a number of domain areas, I've seen my fair share of design patterns. These have often been used for the design of the layers beneath the presentation layer.

I'll break it down a bit.....

It's common to talk about 3-layered models in software architecture and design; presentation which is what the user sees, business logic and data storage layer. I've typically been involved with patterns in the design and implementation of the business logic layer.

In reality, a majority of ecommerce websites have certain things in common and this commonality can be at any of the 3 layers mentioned above. For the presentational layer, these may be the presentation of products within a department, the adding of a product to a cart, the presentation and functionality associated with a basket/cart, and the collection of information necessary to take payment. Not only are there areas of commonality in terms of the information requested or presented, but also clear ways of presenting and requesting that information to increase usability and therefore (hopefully) the likelihood of conversion.

Heading down to the depths of the data storage layer, there's undoubtedly plenty of room for commonality (or patterns) here too, of course driven by the information we need to present or elicit from the visitors and customers to our sites. We have categories of products (which may have several product features, and several product images) that visitors add to their baskets, they then checkout, provide invoice and delivery addresses, card details. We may also have upsell products and cross-sell products which define a relationship between one product and many others, we may have special offers that run for a particular time period, etc, etc. I may be selling flowers to my customers, you may be selling clothes, DVDs, cars. However, there's a level of commonality between the information we present to our visitors and customers for our products and therefore there's a design pattern that could be used to represent common database schemas.

Are design patterns for ecommerce websites new? I think not, the patterns just evolve. Sometimes a pattern in imposed by the ecommerce solution that is being used (whether Actinic, Venda, or any other) or has been developed in house.

We all certainly want our websites to be as easy to use as possible while still maintaining some commonality with other websites so that visitors don't have to learn the idiosyncronies of our sites. Consistency within a site is clearly important, and this is where style-guides can ensure that consistency (in much the same way that the Windows development tool provide common dialogs for file management, error messages etc in order to try and make it easy for an application user to a new bit of Windows software to use it without extensive training to find their way around its interface.

One of the previous posts mentioned The Design of Sites which is a great, if somewhat outdated (in some areas), book on design patterns (for the presentation layer) and includes ecommerce site design. In addition, Chak's Submit Now, Krug's Don't Make Me Think and 37 Signal's Defensive Design For The Web all offer useful design patterns applicable to ecommerce websites. It's clear from looking at some ecommerce sites that these books don't grace the bookshelves of their designers. I've spent a fair amount of time in recent years reviewing other's ecommerce websites, and it's shocking how many common mistakes from 2001/2 that are still made in the design of ecommerce websites today whether related to usability, accessibility, search engine friendliness, information architecture or other. Even more frightening is that the designers 're-use' the same web application structure/code/design to produce ecommerce website after ecommerce website all with little real hope of converting a tiny percentage of visitors to customers.

Design patterns exist, we need to evolve them and make sure that the web-sites of today and tomorrow make use of them. 

James Saunders
Serenata Flowers Limited
http://www.serenataflowers.com