Quite a lot, it turns out…
In Part I of this series, I explored the concept of Cognitive Friction and highlighted the difference between “good” Friction that serves a useful purpose and “bad” Friction that does not. I noted that, all too often
“Friction is deployed unknowingly, unthinkingly or without the designer fully understanding the nuances of the impact it will have on the target population.”
In this, Part II of the series, I want to tackle that challenge. Firstly, by equipping my readers with an understanding of what “good“ uses of Friction are so that they can assess whether the ways in which they are currently deploying it are appropriate and effective. Secondly, to help them identify situations that are relatively frictionless, where perhaps the introduction of Friction might serve a useful purpose. Finally, I hope it will also reveal where they are unknowingly deploying Friction and could review its use.
As with most behavioural interventions, the determination of whether a particular use of Friction is “good”, or indeed “fair”, is a matter of perception. Context also matters; the use of a specific form of Friction may be entirely acceptable in one situation, but unacceptable in another.
In this blog, I will cover three broad categories of Friction:
Preventative designed to stop the target audience (“users”) from doing something undesirable;
Qualitative designed to improve the quality of the user’s decision-making; and
Engaging designed to improve the user’s engagement.
These are not “neat” categories; some uses of Friction will focus specifically on one of these objectives, others will deliver two or even three. While I am attracted to the concept that Friction, like Smartphone Apps, should focus on doing one thing well, I also think there is a strong argument that meeting more than one is also a good thing. After all, if we are going to slow something down or make it harder, then it is easier to justify doing that when we’re meeting several objectives rather than just one.
I should add that the categorisations I have used for Friction intentionally focus on the desired outcome, rather than the mechanics used to get there. Readers familiar with Daniel Kahneman’s Thinking Fast & Slow, might want to think about the interplay of the various examples with System 1 and System 2 thinking. I won’t explicitly cover it here, because I want to look at it later in this series.
The examples I give will lean heavily, but not focus exclusively, on the digital environment (“Digital”). Not because the techniques aren’t relevant in the physical world (they are!) but rather because Digital makes it far easier to design and implement Friction. It also allows for a degree of flexibility and personalisation that the physical world renders difficult, impossible or prohibitively expensive. That said, many examples of Digital Friction lever the same thinking as things previously deployed in the physical world. To prove that point, we’ll begin our review of the different kinds of “good” Friction with a modern-day version of a form of it that we can trace back to the 7th Century BC.
1. Preventative Friction
As the name implies, Preventative Friction is designed to prevent an undesirable outcome.
1.1 Prevent Unauthorised Access.
The idea of barring certain people from having access to a physical location is not new. Hence the invention of the lock and the key; the earliest known versions of which were traced back to Nineveh in Ancient Assyria.
Although this function is increasingly being performed by keypads, fobs and swipe cards, the principle remains the same. In Digital, we use logins, passwords and biometric security devices to restrict access to legitimate users. We’re even using Friction to keep out machines in the form of bots, through the use of CAPTCHA boxes that require us to prove that we’re actually human:

You’ll definitely have come across CAPTCHA, but do you know what it stands for? The answer is Completely Automated Public Turing Test To Tell Computers and Humans Apart.
So now you know. Sometimes they use pictures rather than words. To understand the fascinating reason why I recommend this article.
1.2. Prevent Errors
Our second form of Friction will also be well known to you. Try to delete a file, and you’re almost bound to come across a message like this:

This form of Friction is designed to prevent us from making mistakes. It is so easy to implement that system designers now routinely use it to guide us through decisions where the worst case outcome is that we are inconvenienced or confused. After all, a deleted file can usually be recovered if the deletion was in error.
Preventative Friction is also deployed in more critical situations where the consequences of the decision are irrevocable, and/or where there is a chance that the user might not fully comprehend the magnitude of the impact of their actions. Like this:

To achieve their objective, the two previous examples rely on the user being able and willing to reject a particular outcome. But even when those presumptions might not apply, preventative Friction can still play a useful role.
Here’s a compelling case study involving “over-the-counter” (OTC) drugs; those that are available for purchase without a medical prescription. Because they are easier to purchase than prescription drugs, there is a higher risk that people using them will overdose; either accidentally or on purpose.

To reduce this risk, the UK imposed packaging requirements on manufacturers. As this NY Times article explains:
“In September 1998, Britain changed the packaging for paracetamol, the active ingredient in Tylenol, to require blister packs for packages of 16 pills when sold over the counter in places like convenience stores, and for packages of 32 pills in pharmacies. The result: a study by Oxford University researchers showed that over the subsequent 11 or so years, suicide deaths from Tylenol overdoses declined by 43 per cent, and a similar decline was found in accidental deaths from medication poisonings. In addition, there was a 61 per cent reduction in liver transplants attributed to Tylenol toxicities.”
This is a really smart intervention. On the one hand, the packaging serves to deter people from overdosing, either deliberately or accidentally, in a way that selling it in a bottle would not. But the Friction it creates also serves a useful purpose for the average user; the blister pack gives a clear visual indication of how many pills the individual has taken, making it easier for them to medicate in the right dosage. An excellent example of Friction serving more than one purpose.
1.3 Improve Data Quality
Friction can also be used for data quality assurance. Fill a form in on a website, and you’re likely to find the data you enter being subjected to Form Validation checks, which ensure the accuracy of the information that is entered. For example, to prevent a user from registering with an email address that has already been used, or to ensure the address is in the right format. Like this:
In this example, Form Validation operates in two distinct ways. Firstly, it introduces Friction on a reactive basis, when it detects an error in what a user has typed. Secondly, it does so on a pro-active basis by requiring the user to re-enter their chosen password twice. The latter is necessary because the system has no way of knowing whether the password the user has typed in is what they intended; hence it requires it to be entered a second time.
Typo prevention isn’t the only use-case. Enter an event on a date that has already passed and many Calendar programs will ask you to confirm that you really did mean to create an entry in the past. The presumption on the part of the designer, being that most people won’t want to do this; unless, of course, the user is Stephen Hawking, attempting to discover whether time-travel is possible.
1.4 Deterrent Friction
To experience the next type of Friction, I recommend trying to get into a nightclub without being on the guest list. You’re highly likely to find yourself standing in a line for an arbitrary amount of time before you’re subjected to assessment by the door staff who will determine whether or not they’re happy to let you in, based on a set of criteria that appear to be modelled on the whims of Roman Emperors.

Arbitrary or not, it’s an excellent example of Friction which is mostly there to deter or prevent undesirable users. In situations where something is offered, either by design or unavoidably, to a larger population than is the intended target, Friction permits screening to occur.
Nightclubs need to publicise their existence widely to attract people who will want to go, but they don’t want everyone who knows about them to come in. Of course, it isn’t the only reason they make people wait in line; we’ll come on to those later on.
The use of Friction as a deterrent is explored by Cass Sunstein in his research on “sludges” in the context of benefit payments:
“If the process of getting benefits is too easy, people who don’t actually need the benefits may be incentivised to apply for them as well. As a result, those who need them most may not get the benefits because the money has already been given to someone else. Adding in a bit of sludge, like annoying paperwork, could stop those who don’t actually need benefits from trying to get them.
But does this count as sludge? While this practice doesn’t look after the self-interest of every single individual, it does look after the self-interest of certain individuals: those who are most in need.”
The obvious counter-argument to this form of Friction is that it sounds good in principle, but there are likely to be unintended consequences. If you make claiming benefits too hard, you will deter those that don’t need them, but you’ll also put obstacles in the path of genuinely deserving people who might be least able to afford the time and cognitive load required to navigate the sludge. However, outside the context of social security, there are other valid reasons for deploying this kind of Friction.
Take Snapchat. For reasons I’ll come on to, it is highly likely that many of my readers might not know what it is. Those that do can feel free to skip on to below the Snapchat logo. For the uninitiated, Snapchat is a multimedia messaging app that allows users to send “Snaps” (pictures and short videos) which are automatically deleted after a pre-set amount of time; immediately once they have been viewed by all participants or after 24hours if the sender chooses this option.

The reason I suspect that some readers won’t be familiar with Snapchat is that was intentionally designed to target younger users, and implicitly exclude older ones. Both in the user proposition, but also in the execution of the idea. Most obviously in the UX (User Experience) which can be incredibly frustrating for anyone who is, to make a sweeping generalisation, aged 35 and above. Snapchat’s CEO, Evan Spiegel, has claimed that this is on purpose, insisting at a conference that:
“This is by design. We have made it very hard for parents to embarrass their children.”
In other words, they can’t stop parents from downloading it, but they want to deter them from using the service. Don’t believe me? If you’ve not tried it, give it a go. While some of you will find it easy, it’s likely to put many of you off. Admittedly, as this article highlights, SnapChat has recently made some changes designed to address this issue, but the fundamental Frictions that were there in the inception of the App remain and are very powerful.
Community websites face the same problem. They want to be accessible to everyone on the internet, to reach their target audience, but they want to control who participates in their community. Product Hunt, a tech review website, makes aspiring contributors jump through a number of hoops. They explain their reasons on the right:

By effectively increasing the barrier to entry through Friction, they are able to weed out users who don’t show sufficient commitment to the cause. Contrast that approach with frictionless signups to social networks like Twitter where the upside of no user screening is that everyone can join and share their wisdom. The downside is that everyone can join. Including ill-informed Dunning-Krugerites who can spout nonsense to a global audience.
2. Quality inducing Friction
2.1 Improve the Quality of Decision-Making
Having filtered out undesirable users, let’s now look at how we can use Friction to help improve the quality of the decision-making of the users we do want. The best example of this is the “cooling off” periods which regulators require financial services firms to offer their customers for certain products.

Photo by Tomek Baginski on Unsplash
Studies have shown that these can be very effective. A recent one entitled, “Cooling Off and Backing Out” examined customer rescission (i.e. the reasons why consumers rescinded) during cooling-off periods and identified that they tended to do so for very compelling reasons, including:
“a mismatch between product features and personal circumstances” – in other words, the product didn’t meet their needs;
“post-purchase concerns about product value” – the product was poor value for money;
“reassessment of financial capability“- they couldn’t actually afford it;
“reflections on sales presentations” – they realised they’d been fooled by a slick sales pitch; and
“cautionary influences of reference groups” – they consulted with friends or family who persuaded them it wasn’t a good idea.
What this highlights is that if you give people more time to think about something, they’re very likely to make a better decision. Or at the very least, avoid making a really poor one. Because it isn’t possible to give them thinking time before they buy a product, regulators use Friction to create it artificially after the event.
Friction isn’t just useful for influencing decision-making around products that might inherently pose a challenge for consumers. It can also help when the rationale for making a purchase is more impulsive; particularly when the drivers for that impulse are strong emotions.

Research published in the US last year, highlighted that forcing people to wait before they can acquire a firearm, reduced gun homicides by 17 per cent with no significant increase in other types of homicides. In other words, not being able to buy a gun straightaway, doesn’t mean people just “displace” and commit murder by other means. The reason for this, is the power of emotions in our decision-making, as this Behavioural Science magazine article explains:
“intense emotions like anger and sadness—“visceral factors,” in academic language—can cause people to take actions they later regret, such as resorting to gun violence.
Yet…these emotions are often transitory. Given sufficient time to cool off, the types of intense negative emotions that lead to violent tendencies can pass.
This suggests that inserting even a short delay in the gun-buying process has the potential to reduce gun violence, without restricting anyone’s right to own a gun.”
The concept of a cooling off period is not new. The Preußische Beschwerdeordnung was a Prussian Army law that required anyone who wanted to file a complaint to their superiors to wait for a certain amount of time (the so-called “Prussian night”) after the complained-about incident occurred. A cynic might conclude that this was less about ensuring the quality of complaints was high and more about the introduction of Sludge to keep the number down. Perhaps it was both.
2.2 Improve Recall
Struggling to remember things you’ve read? Try Sans Forgetica, a downloadable font created by Melbourne-based RMIT University’s behavioural business lab and design school, that is scientifically designed to help students remember their study notes. It looks like this:

The font deploys something called “desirable difficulty”. What we know as Friction. As the designer explained to the Guardian newspaper:
“When we want to learn something and remember it, it’s good to have a little bit of an obstruction added to that learning process because if something is too easy it doesn’t create a memory trace.
If it’s too difficult, it doesn’t leave a memory trace either. So you need to look for that sweet spot.”
The idea of finding balance in creating Friction is also relevant to our next category.
3.Engagement driving Friction
3.1 Goldilocks Tasks
In his book Drive: The Surprising Truth About What Motivate Us, Daniel Pink refers to what he refers to as “Goldilocks tasks”:
“challenges that are not too hot and not too cold, neither overly difficult nor overly simple.”
He explains why these are important:
“One source of frustration in the workplace is the frequent mismatch between what people must do and what people can do. When what they must do exceeds their capabilities, the result is anxiety. When what they must do falls short of their capabilities, the result is boredom. But when the match is just right, the results can be glorious. This is the essence of flow.”
A need for balanced Friction is also a key component in Gamification; the application of techniques commonly found within game environments which are widely used to drive user engagement. It works because we’re naturally drawn towards playing games; whether on a computer screen, the page of a magazine, a board, or on a sports field.
Friction is a pre-requisite for games. Without challenges for the players there would be no reason to play, but make them too difficult, and players will give up. Getting this balance right is the essence of a good game. Take the board game Othello:
