When your web site sells more than a dozen items, you may face a fierce challenge of helping shoppers find what they are looking for. You'll need to classify products into categories, but these will serve as obstacles and even deal killers if those categories do not match those in the heads of shoppers.

I've seen again and again web sites using classifications that aren't known or understood by a portion of their customers. For instance, I once wanted to buy T-shirts and went to the site of a famous catalog company, where I found a category called "shirts." So far, so good. But then I had to choose between a category called "woven" or another called "knitted." There I got stumped. Are T-shirts woven or knitted? I was not sure.

Another time I was searching for a Toyota car part, ready to buy it, but I could not find it on the Toyota parts web site unless I knew whether it was part of the drive train, an accessory, the exhaust system or something else. I hadn't a clue. In both these cases, the site wrongly assumed that shoppers understood their jargon, and set that up as a barrier to an online purchase.

Let's suppose that you solve the jargon problem and someone finds what they are looking for. The next hurdle for shoppers concerns whether or not people can find answers to all the questions about availability, shipping charges, warranties and return policies that they could easily ask if shopping by phone or in person. In the last year, I would say that only 50% of the time when I'm shopping online I've had all of my pre-purchase questions answered by the web site. Among the multi-product sites I've toured as a reviewer, I don't remember a single one that answered enough questions for shoppers.

Before your site launches, you can think up all the questions people might ask by imagining different kinds of shoppers - people from other countries, corporate buyers, gift givers, etc. - and what they'd need to know. Once your site's been up for a while, collect the questions that come in by email and phone. Gather the questions and answers in a Frequently Asked Questions page and make the FAQ accessible from every page of your site.

Especially do not make people put items into their shopping cart and begin checking out in order to find out the shipping charges and refund policies! Another epidemic blunder is not revealing the address of the company behind the shopping site. Not only is this necessary to set at ease the mind of any shopper worried about recourse against no-show orders or faulty merchandise, it's important for some people to know where items are being shipped from.

Ditto for your privacy policy. Are you going to be renting out your list of customer addresses and bombarding everyone who's bought from you with frequent emails?

Online order forms range from easy to use and complete to baffling and aggravating. Submit yours to what I call "the grandmother test" - ask people who've never seen your site before to place an order and talk through the process out loud. Button your lips and listen. Note where they get stuck and fix your ordering procedures accordingly.

Finally, do you have testimonials attesting to the quality and value of what you sell and the pleasures of doing business with you? That's the cherry on the sundae of a well-designed site from a company shoppers recommend and return to for more purchases!

Marcia Yudkin is the author of Web Site Marketing Makeover and 10 other books. A four-time Webby Awards judge and internationally famous marketing consultant, she critiques web sites and performs web site makeovers for clients. Learn more about her detailed critique sessions on five different kinds of web sites (including multi-product sites) at http://www.yudkin.com/websitequiz.htm .