The Cost of More: Psychology of Choice in Interaction Design

There has always been a difficult balance in the amount of choice offered to consumers. Too little choice means a store may be omitting services or products important to some users (and worse still, that a competitor might include). Too much choice adds complexity with increased potential for confusing or frustrating potential purchasers.

This may sound a big enough challenge to cope with, but according to Barry Schwartz, the author of The Paradox of Choice, the difficulty I have just described is only the tip of the iceberg. While Schwartz deals primarily with choice outside the digital world, I believe that too much choice and how it is presented to users can have serious implications for the web.

A fundamental theme of Paradox is the difference in strategy between people who are satisficers and those who are maximizers. While satisficers are content to select products (or services) that meet a minimum set of requirements, maximizers want to make sure they have made the best possible decision. Schwartz and his colleagues discovered that:

1. Maximizers engage in more product comparisons than satisficers, both before and after they make purchasing decisions.
2. Maximizers take longer than satisficers to decide on their purchase.
3. Maximizers spend more time than satisficers comparing their purchasing decisions to the decisions of others.
4. Maximizers are more likely to experience regret after a purchase.
5. Maximizers are more likely to spend time thinking about hypothetical alternatives to the purchases they've made.
6. Maximizers generally feel less positive about their purchasing decisions.

An immediate implication of this is that web sites that work well for satisficers may not be as successful for maximizers who, in effect, have different needs. For example, filtering products on criteria such as cost and features may be an ideal solution for satisficers while maximizers may not be happy with anything less than extensive comparisons between the choices available. If nothing else, this suggests that sites should be tested for both types of user (Schwartz helpfully includes questionnaires for differentiating between the two).

But there is more to the psychology of choice than you might think. Too much choice can in itself be demotivating. Schwartz gives an example of a gourmet food store with two displays of jams for tasting on different days. The smaller display consisted of 6 varieties while the larger had 24. In both cases people tasted about the same number of jams. However, while 30% of those who tasted made purchases from the smaller display, this figure dropped dramatically to only 3% for the larger display. Although this result may not be directly transferable to e-commerce, I know from my own experience that I have abandoned sites where there have been too many similar products with inadequate descriptions.

At a higher level there is the choice of which web site to use in the first place. This decision is affected by how users remember experiences. Schwartz describes the peak-end rule of Daniel Kahneman and his colleagues: what we remember about the pleasure quality of past experiences in determined by the high (or low) point and how experiences felt when they ended. This means that for users to have a positive memory of a particular web site the experience must not only be good overall - it must also finish on a high note. Unfortunately the checkout process is frequently the most complex and least satisfying aspect of many e-commerce sites, leaving those sites with a quick and easy checkout (such as Amazon's 1-Click) at a clear advantage. The peak-end rule also suggests that if a site has any bad news for its users, it should not be saved until the end. Product availability, ticketing charges, delivery costs and the like should be made available at the earliest relevant opportunity. While there is always the hope that users will have invested so much time and effort in reaching the checkout that they will not mind a few last-minute charges, the likely effect on their experience of the site may well curb any enthusiasm for a return visit.

Reference

Schwartz, Barry 2004. The Paradox of Choice, HarperCollins: New York, NY
[Amazon.com]   [Amazon.co.uk]

The Author

William Hudson is principal consultant for Syntagm Ltd, based near Oxford in the UK. His experience ranges from firmware to desktop applications, but he started by writing interactive software in the early 1970's. For the past ten years his focus has been user interface design, object-oriented design and HCI.

Other free articles on user-centred design: www.syntagm.co.uk/design/articles.htm

© 2001-2005 ACM. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in interactions, {Volume 12, Issue 2, March + April 2005} http://doi.acm.org/10.1145/1052438.1052479