Persuasive Design with Spencer Gerrol

Recently I attended a great presentation by Spencer Gerrol (Human Factors International) in Atlanta entitled “Beyond Usability: The Science of Persuasive Design”. Gerrol discussed how important it is to not only make our websites easy to use, but to make people want to use them. He then discussed 6 key principles we can use to persuade our customers as well as some important persuasion tactics to keep in mind. The presentation began with a brief discussion of the difference between usability and persuasion.

Usability vs. Persuasion

Usability, Gerrol summarized, is making it easier to get somewhere or do something. Persuasion is making the user want to get there, or perform the task in the first place. Without persuasion, simply making something easy to do, doesn’t necessarily make it something people want to do.

Persuasion Research & Testing

Next we talked about how to gather initial research and data before beginning a new design. As with usability, persuasion design requires proof of concept and proof of ROI, therefore some quantitative data must be gathered. For this Gerrol highly recommends some sort of analytics on the back end. These numbers will give you solid data for comparison before and after design changes are made. This data can also help gather initial information about where users are currently going, and where they are dropping off your site.

Persuasion testing, much like usability testing, would typically be done by observing users as they complete tasks. The major difference however with persuasion testing, is that you are not presenting the user with tasks to follow. Instead you are looking for users who are already interested in performing the type of tasks your looking to study, and then watching as they find their own way, and understanding what motivates them to take those paths.

6 Keys to Persuasive Design

Gerrol then went on to discuss the 6 ingredients to keep in mind when creating persuasive designs.

1. Understand Decision Making: A decision cannot be made with out both emotion and reason at some degree. There for in order to begin persuading users, you need to not only appeal to their emotions, but to also understand their reasoning behind making a decision.

2. Understand Emotion: It is important to understand drivers of different emotions. For example what evokes interest, hope, excitement, and anticipation? Why do people ride rollercoaster’s? Why do people play the lottery? Once you’ve picked the right emotions, knowing how to evoke these emotions in your design will help you to keep your users engaged.

3. Create Persuasive Interactions: Once you have an idea of the emotions you want to invoke, you can begin to create interactions that elicit these emotions. For example, think of our rollercoaster ride. If you could just walk up and jump on, it takes out a lot of the excitement. While we all complain about the long lines at amusement parks, they are a big part in playing into our anticipation, fear, and excitement. It turns a 30 second ride into a 1hour experience, and in the end makes you feel more like your money was worth it.

4. Create Persuasive Visual Design: Today more than ever, people make decisions quickly. We are in a generation of ADD web users. Therefore it is important to visually grab their attention. What words, pictures and colors will most likely appeal to your audience? Some good exercises that can be done to help are things like word associations, and A to B testing.

5. Create Persuasive Content Design: Use content to market the benefit, how is this deal good for the user? One way to do this with cost is to break down numbers in to more manageable terms. For example, instead of “only $299 pr year”, try “just 24.99 a month”. Some other ways are to show the value of savings, are interactive calculators, comparisons to other services of a higher cost, etc.

6. Design Guided Paths: Guided paths are used as a discovery channel for the users. It’s a way to up-sell and cross-sell the user and keep them exploring your site. An example of this is with insurance, let’s say you buy car insurance, maybe the next thing they show you is how you can now also save on homeowners insurance with them, or how you can add another car to your insurance plan, or join their road side assistance club.

Persuasion Tactics

Finally Gerrol briefly discussed some basic persuasion tactics that each designer should keep in mind when designing for persuasion. Here are some examples:

  • Optimal level of dissonance – we are intrigued by unusual things, so long as they are believable enough not to loose credibility.
  • Because – Give people a reason to feel good about their decisions, for example “Because you deserve a break” or “Because A&B Co rated us #1”
  • Contrast Principle – show how good this is in comparison to something else.
  • Visceral Processing – use colors, lines, images etc to make attractive interfaces that stimulate the brain and elicit positive emotional responses
  • Social Proof – Show how many items have already been purchased, how it’s a top 10 deal, that a credible source rated it, etc.
  • Social Learning – Show how others rate the product, customer comments, testimonials, etc.
  • Scarcity – There just isn’t much left, this is a limited time offer, etc.
  • Extrinsic Reward – Give users an incentive or a reward to provoke action, such as bonus air fare mileage, or 2 free months of service etc.
  • Conditioning & Association – Pair images, such as a couple relaxing on a beach when trying to sell flights to Jamaica.
  • Writing Public Statement – When people right down a wish or goal they are more likely to act on it, such as shoppers wish list.
  • Laddering – Use successive small agreements to lead people into a larger agreement, such as putting an item on hold for them for 24 hours.
  • Resolve Suspicions – Where possible show that there is no “catch”. For example “Tax Included” or “No additional fees.”

I found the presentation to be very informative, aside from Gerrols great use of slides and presentation techniques, the idea of persuasive design itself can be very useful. In my opinion, persuasion design attempts to bridge the gap between traditional marketing and user centered design. It is important that in listening to our users we don’t forget about creating successful interactions that also lead to positive conversions and increased sales.

Let’s say you are planning on taking a vacation this summer, and logged on to a travel site to browse some deals. Yes, the site is easy to use and looks good, but your not really planning on purchasing anything yet, more just window shopping. However you find a great looking deal. Just looking at the picture you can see yourself sitting in the sand, it is limited time only, has great reviews, the price seems unbeatable, and this looks like a reputable site. So you think about it for a minute and then commit. Besides, you were going to buy a ticket soon anyways, right?

If you are interested in learning more about persuasive design, Human Factors International offers a 3-day class on PET design (PET = Persuasion, Emotion, & Trust).