UX and psychological persuasion in design (Part 3)

by Jack Josephy on 10 November 2015

In part 2 of this series (start at part 1 if you haven't already read it), I looked at what some of the tools are that designers use to get users' Attention and Interest. The last two steps of the journey can also be influenced by design however, by increasing Desire for a product, and finally driving users to take Action to complete a purchase, get in touch, etc.

UX design looks at how users interact with a service, while psychological persuasion looks more closely at the 'why'.


In Part 1, I established that the traditional AIDA (Attention, Interest, Desire, Action) model used in marketing is an effective framework to think about how design can help persuade and motivate a user. Desire also focuses on continued increase in user motivation, before finally triggering Action and removing any final cognitive barriers.


I'm sure we've all heard a story at some point that grabbed our interest so much, that we had to know what happens next, even if it ends up disappointing us. It might be a book that's a 'page turner', or a tv show that you have to 'binge watch'. The same principle can be applied on a smaller scale in design. While you might think that giving users all the information they need is ideal, sometimes teasing users can actually result in an increase in curiosity and desire for a product or service. This is related in large part to the principle of 'loss aversion', or the fear of missing out.


Fig 1. By teasing their expertise, KissMetrics can encourage people to explore their website.


If we have anything in unlimited quantity, we tend to take it for granted. It isn't until a resource becomes scarce that our desire for it suddenly increases. This is down to a hard-wired evolutionary mechanism: in order to ensure survival, our brains push us to consume scarce resources as soon as we can. It's a powerful motivator that designers take advantage of through methods such as indications of limited stock levels, or time limits on deals.


Fig. 2 Limited time offers create a sense of scarcity, which in turn affects decision making

Risk aversion

Taking less risk is a good rule of thumb to ensure survival. It still applies now in many decisions people make, but it can manifest in a slightly different way. A big perception of risk today revolves around monetary cost. 'Free' is seen as an indicator of an option being low risk but this often isn't the whole story. Other risks and costs might not be highlighted, whether that's requiring card details before starting a free trial period (likely rolling the service automatically onto a paid subscription), or not mentioning the time and hassle involved in returning a product. By highlighting the perceived low risk, an option becomes more attractive to us.

risk aversion 1.png

risk aversion 2.png

Fig. 3-4 Spotify and booking.com are two examples that try to emphasise the lack of risk in trying or using their services


The final goal for any designer is to trigger their users into completing an action, nudging them at just the right time. This could be completing a single action (e.g. filling in a 'Contact Us' form), or it can be a series of tasks (e.g. going through an e-commerce payment transaction.).

Calls to Action

Displaying what the ultimate goal of a page or website is in a clear, obvious way makes it easier for users to complete the action.

Call to Action.png

Fig. 5 A clear call to action for users helps to direct and encourage them to act

Email prompts

Another year has gone by, and Mother's day has come around to ambush you once again. What are you going to get her this year? A well-timed email from Apple can encourage you to fulfill their desired action, completing a purchase of an iPad.

Email Prompts.png

Fig. 6 Well-timed emails and prompts can increase the likelihood of user action

Promote further exploration

Not every page is all about performing a definite action. Blog pages (like this one) might just be there to share insight and information. However, it is worth asking users to explore content further, by promoting further exploration at the bottom of a page (this page is no exception!).

Footer Cue.png

Fig. 6 Encouraging further users to explore content further can be the main goal for a webpage

Limit choice

Choice is often lauded as the ultimate empowerment for consumers, but the reality is that having more choices makes things harder for users. One example involves an experiment conducted by Iyengar and Lepper, where consumers could choose from a selection of 6 jams, or a selection of 24. The latter failed to boost the shoppers' purchasing willingness: 3% of shoppers bought jam from the 24-item selection, while 30% bought jam from the 6-item selection.

Having to compare many different options takes time and effort, and often this can serve as an obstacle for consumers coming to a final decision. Limiting things to just a small number (3-5) of options, while still allowing for some choice helps consumers to make a decision faster.

limit choice.png

Fig. 7 Keep things simple for your users by limiting the total number of choices

Limit time available

Similar to the above, limiting the time users have to complete actions will provide incentive to complete the task, as they'll be subjected once again to the fear of losing out. Users are given a strong incentive to avert a loss, rather than dropping off with a filled shopping basket. You can frequently see this in online purchasing for tickets to concerts or events, where users get a limited amount of time to pay before the tickets they want are released back onto the market as 'available'.

limit time.png

Fig. 8 Limiting the time available for a user can act as a strong trigger for action

Smart defaults

Designers put a lot of thought into making the default settings as close to user expectations as possible. People tend to be lazy and don't want to spend time going through many fields, filling them out to be correct. By breaking down cognitive barriers and removing the need for users to make unnecessary decisions, design can make it more likely that they will complete the action.

Making smarter default settings will ensure more users complete the action. Good examples of this are forms that automatically fill based on previous information provided, and Amazon's 1-click order button, which fills all fields up with the user's default information and completes a purchase instantly.

smart defaults 1.png


Fig. 9 Amazon's 1-click buy button is an example of a service taking advantage of smart defaults


I hope you've enjoyed this short series on psychological persuasion in design, it's an area I have a lot of interest in and I see it as a close companion to the UX work that we do here at Webcredible.

If you'd like to hear more about it, I'll be delivering a webinar on this subject on the 4th of December 2015, and I'll be happy to answer any questions or discuss any thoughts you have on this subject.

Thank you for your comment. It has been submitted for approval.

Comment Again?

Leave a comment

Please enter your name.
Sorry, this email address is not valid.
Please enter your comment.

Course basket x


Price per place

Add another courseCheckout

Pay now by credit card or later by invoice (invoice payments only possible if all courses are 3+ weeks in advance)