Interaction Elasticity

Interaction Elasticity and the Impact on Usability

Jakob Nielsen’s latest Alertbox on Interaction Elasticity is a very interesting read. If you’ve not read it yet I urge you to read it.

If you’re responsible for an eCommerce website then pay close attention, my post impacts you even more (see below)!

According to Nielsen, we always want to use numeric rules for usability questions, questions such as:

• How many clicks is the right number to a product page?
• How many links is the right amount in a navigation menu?
• How many seconds will someone wait before a slow download makes them exit?

I know I’ve asked those exact questions before. Maybe you have too. According to Nielsen, there is no single number that answers those questions, or questions like them.

Elasticity – Demand Drops as Cost Increases

Nielsen introduces the concept of Elasticity, which in Economics is usually attached to demand and price. The idea is there is no single price at which people will suddenly decide to buy, or not buy a product. This is because demand (or motivation) impacts the elasticity or willingness of a person’s decision to buy.

According to Nielsen, this same concept can be applied to usability. The motivation of the person using a website and the cost they have to pay in interacting with the site will impact how elastic that person is to usability issues on the site.

If motivation to use the website is high, then you can say that person has lower elasticity and therefore will probably be more likely to put up with an annoying experience. If the motivation to use the website is low, then you can say that person has higher elasticity and will be much more likely to abandon the site if any problems, even minor ones, are encountered. By the way, this is NOT to imply that low elasticity means you don’t have to make your site as usable as possible. Maximizing the usability adds value by generating incremental action on your site.

eCommerce Ramifications of Interaction Elasticity

Although everyone must consider the ramifications of interaction elasticity, eCommerce sites have extra issues to deal with. Why? Because interaction elasticity will vary depending on where in the process of purchasing your customer is.

If your customer is just researching, and is visiting your high level marketing pages, then you can assume that customer’s elasticity is higher, and it’s more likely for your customer to abandon your website if presented with annoyances or problems.

Likewise, if your customer is now going through the order process and is investing time and energy on it then elasticity is probably much lower, meaning it’s more likely your customer will put up with a little more annoyances or problems before leaving. This does NOT mean you can ignore or marginalize issues in your order flow! Rather, the implication is you must also focus with the same concern on your higher level marketing pages as you show with your order flow pages.

If ever you were looking for a reason to increase usability testing of the higher level marketing pages in your website, this is it. The error many eCommerce website owners make is treating their higher level marketing pages like static pages, or just content dumps, and only changing content without examining and optimizing function.

Need a leg-up on your competition? Carefully examine the usability and functionality of your high level marketing pages with a detailed usability test, knowing that finding and fixing minor annoyances or functional issues could have beneficial impact on your conversion.