Applying Curiosity to Interaction Design: Tell Me Something I Don't Know


Given just a bit of information, we naturally crave more. Given a puzzle, we have to solve it. So, as interaction designers, how are we using this bit of insight into human behavior?

The hook

My wife is an expert conversationalist and master of “the hook.” By hook, I mean that simple statement, skillfully dropped in a conversation, and so intriguing you cannot help but want to know more. We can be sitting with friends discussing any topic. If the conversation begins to wane, she’ll casually work in some phrase like “When I worked at a prison, blah blah blah…” When you did what?! And there it is: A hook so captivating you just have to know more!

Great storytellers know exactly how to turn the ordinary—a trip to the grocer—into a suspenseful story by withholding information. In new relationships, flirtation often involves some element of playful teasing, whether through conversation or more sensual revelations. And newsrooms have made a science out of crafting irresistible headlines—“Your PC might be infected!” or “Are you prepared for the tax law changes?”

We are captivated by the unanswered question. To quote JJ Abrams, creator of TV Series Lost, “mystery demands that you stop and consider—or, at the very least, slow down and discover.”

Curious Marketing

In recent years, Hot Wheels has begun including a “mystery car” in their store shipments. Unlike all the other cars encased in clear plastic, this car is shielded by an opaque black plastic—you have no idea what kind of car is in there:

With two or three dozen hot wheels to choose from, guess which one the kids go after? Given the choice of all these “known” cars, the one that—in my experience—gets attention (and allowances) is the Mystery Car—the one that is “unknown.”

Crazy? Perhaps.  But this same bit of psychology also works on grownups.

Here is a rather interesting promotion from California Pizza Kitchen. At the end of my dinner (along with the bill) I was given the “The ‘Don’t Open It’ CPK Thank You Card.”

It’s a coupon, with an interesting twist: You bring this with card you next time you come back to CPK. You’ve already won something, from a free appetizer up to $50 dollars (or more). But you don’t know what you’ve won until your next visit (see where this is going?).  The instructions are pretty clear: Whatever you do, do NOT open this or whatever you’ve won is null and void! A manager has to open this for you when you return. You are guaranteed to get something worthwhile—and this is a critical part or arousing curiosity. Coupons are too explicit—”here is your 20% off.” Scratch offs and lottery tickets are most likely to reveal nothing. Here, the fine print teases you with a list of the possible prizes. Now I’m curious: which prize have I won? This is a mystery that needs closure.

So back to my question: How are we—as interaction designers—leveraging curiosity in our designs?

A Venture into the Unknown

In writing this, I’ve been thinking about two kinds of information: “known” and “unknown” information.

As UX professionals, we excel at making things known. If it’s unknown, it’s unclear and likely to be confusing. A puzzling button label? Make it clear. An unclear process? Make it more familiar. For good reasons, we value things like (user) control, clarity and consistency. We remove uncertainty in interfaces.

But once we’ve removed all the usability potholes from a particular path, how can we reintroduce the simple thrill of driving? How can interactions be made more effective—and fun—by introducing a bit of (controlled) uncertainty?

Let’s go back to our Hot Wheels and CPK examples. Did you notice these things?

  1. Some tiny bit of information makes us aware of something that is unknown. Black plastic packaging hides a toy inside, or we are presented with a mysterious card.
  2. Context provides some relevance. These are kids, shopping for a toy. I’m found eating at a restaurant I presumably like.
  3. Enough clues are given to help us make a judgement about the personal value of that unknown information. Kids who like Hot Wheels can infer that this car will be similar in quality and possibilities as the surrounding options. The fine print on the back of the card explains the range of possible options. Value can come in many forms: the winning lottery ticket; the satisfaction of solving a puzzle; being entertained by a story.

Information can be presented in a manner that is straightforward or curious. If we opt for the latter, we are guaranteed not only attention, but likely higher engagement as well—curiosity demands we know more! What was known information (a simple coupon or another toy car option) that might have been ignored has been converted into something unknown, something mysterious, something that demands resolution.

“Information-Gap Theory”

When we become aware of this missing information- when something changes from being known (or so we thought) to an unknown state—we become curious. This is the explanation of curiosity posed by behavioral economist George Loewenstein in his Information-Gap Theory. Loewenstein says “curiosity happens when we feel a gap in our knowledge.”

The feeling we get from these information gaps is best described as deprivation, which is critical to understanding why it is we are motivated by curiosity. In order to “eliminate the feeling of deprivation,” we seek out the missing information. This is of course ironic, considering that we routinely seek out puzzles, mystery novels and other curious situations that create this sense of deprivation. However, it’s important to note that many researchers once viewed curiosity as something aversive; a decision-theoretic view suggests we should only want to know something if it helps us make more informed decisions. Why would be attracted to something that offers no extrinsic benefit? Many other debates have surrounded curiosity: Is curiosity internally or externally stimulated? Is curiosity a primary drive, like hunger or fear? Is curiosity a state or trait? And this one: “If people like positive levels of curiosity, why do they attempt to resolve the curiosity?”

In his 1994 publication “The Psychology of Curiosity,” Lowenstein surveys the body of curiosity research, much of which occurred in the early 1960s and 70s. In doing so, he provides and backdrop by which to understand his own research and how it resolves many of the debates surrounding curiosity. Simply stated: I’m curious because there’s a gap between “what I know and what I want to know.” Two notable implications come from this perspective:

  1. The intensity of curiosity correlates to the likelihood of certain information to resolve the information-gap. Loewenstein’s own tests confirmed that subjects were more curious when given parts of a greater whole—the need to complete enough of a picture puzzle in order to determine what it was (a picture of an animal) resulted in more interaction than a scenario where each block was a discrete picture.
  2. Curiosity correlates with our own understanding of particular domain. The more we know about some topic, the more likely we are to focus on our own information-gaps. If I know 8 of 10 items, I’m more curious about the remaining 2 than if I only know 2 of 10 things.

Business Application?

Given that curiosity reflects a desire to close information gaps, how can we apply this to interaction design?

First, consider some business situations where you might want to motivate people through curiosity.

  • You have a great product, but low adoption
  • You need to get the attention of the casual visitor—you operate in a crowded space and aren’t perceived as having any differentiated value
  • You’re trying to increase the number of registered users
  • You have a high bounce rate—visitors aren’t coming back to your site

In each of these cases, no matter how good (or bad) you product is, people aren’t giving it the time of day. You need ways to get people’s attention—and to “nudge” their behaviors. Below are a few examples of companies making effective use of curiosity for just such a purpose:


Let’s illustrate this “gap” in knowledge with a look at the professional networking site LinkedIn. One of their business goals? Sell paid accounts. Like most businesses, they have a generic description of the benefits you receive with a paid account. Think of this as “general known” information. While this information could certainly be compelling, there’s a population for whom the cost may not be worth the perceived value.

Of course, those customers with paid memberships have access to specific known information:

This is how most businesses run: “Cross the [registration / paid account / personal information ] threshold and you can have all this!” Unfortunately, this generic description of benefits is often not enough for many people.

One (of many!) things LinkedIn has done is to give you a personalized glimpse at what could be known:

Essentially, LinkedIn is teasing us with bits of relevant information: “Someone at this [specific company].” “A [specific role] at x company.” They move us into an unknown state by sharing bits of knowledge that could be fully known, as a paid member. Nothing has been given away for free—I still don’t know who looked at my profile, but I am aware of some partial knowledge that might be worthwhile to know in full. As one friend said, “If I know someone from Apple has been looking at my profile, you can bet I want to know who!”

If this partial information proves relevant and valuable, you’ll want to know more, right? In essence, they’ve created a zone of curiosity between two previously known states.


Quantcast does something similar, only they’ve created a much larger “zone of curiosity.” You can, with nothing required of you, get a ton of free and quite useful site metrics: traffic stats, demographic information, lists of similar sites and so on. The value to a site owner is obvious. But there’s a bit of information withheld: to get Business Activity data, you must “Get Quantified.”

What’s nice about this version of Quantcast’s call to action is what we our brains see: something being hidden from us. You can almost see through the sticker covering some data! Obviously, this is a static image—there is no live data there beneath a sticker. But we think in images and this visual affordance registers as: “Here’s a sticker. We need to know what’s underneath it. We can’t allow this knowledge to remain unknown!”


Netflix leverages these same ideas when returning a movie rental. For Netflix, the data from your movie rental preferences is gold. Rating a movie not only improves your recommendations, but we as a collective improve the entire recommendation system. Consequently, the site is built around this idea of rating movies. So why then, would they ask you “Rate your recent return to reveal 2 movies you’ll love?”

There is an immediacy to this request—we see the empty slots where two movies will be revealed. Sure, I can rate movies and get recommendations all over the site, but there is something more immediate (and novel) about how this presented.
As with Quantcast, I see the thing I want to take action on; I’m presented—visually—with two unknowns. For the “cost” of rating this movie, I can reveal two more (hopefully interesting) movies. I can make the unknown known.

Specific Motivation

It is human to be curious. And human to pursue a mystery until it is resolved. This has motivated scientists and explorers for centuries. If teased with a bit of interesting information, we want to know more. But to be clear, what we’re talking about here is a very specific kind of curiosity.

In the early 1950s, D. E. Berlyne was one of the first researchers to propose a categorization of different types of curiosity: He identified two dimensions of curiosity: one extending between perceptual and epistemic curiosity; the other spanning specific and diversive curiosity. I’ve plotted these below with a few of examples based on my own understanding of his research.

Although Berlyne’s conception of curiosity has been challenged, it still remains the backdrop against which many subsequent curiosity studies have defined their research. I’ve found this model useful for thinking about different kinds of curiosity and clarifying which flavor of curiosity is most easily applied to interaction design.

In the context of this article, I’m referring to a perceptual-specific curiosity, one in which we confront people with very specific gaps in their knowledge in a novel manner or context. While you can certainly create “gaps” in knowledge in a variety of ways, the examples in this article are more concerned with a variety of curiosity akin to teasing.

Now what?

If you want to make someone curious, make them aware of something they don’t know. Find that information you can use to tease people. Chances are, you’re either withholding all the specific information or giving it all away. To get attention and engage the senses, look for ways to turn these direct messages into a quest to be completed. A few tips:

  • Your “tease” needs to be interesting, or at least proportionate in appeal to the cost required
  • Strive to make this personally relevant to your target user
  • Make the promise of something worthwhile—what’s it going to cost people?
  • Establish trust through other givens and context clues
  • Use visuals suggest or create the immediate perception of mystery
  • and,

  • if you’re trying to lure me with something that is given away freely elsewhere—don’t.

With that, I’m curious to see how you work these ideas into your interactions!

Stephen Anderson

Stephen recently published the Mental Notes card deck to help product teams apply psychology to interaction design. Between public speaking and consulting, he offers workshops to help businesses design fun, playful and effective online experiences. He’s currently writing a book about “seductive interaction design” that will be published in 2011.

24 comments on this article

  1. The summation for this article, to me, is “how can we reintroduce the simple thrill of driving?”

    As better analytics and research data allows to create tighter, more streamlined paths for our visitors, we turn the very act of visiting into a mechanical process. Step 1, step 2, get information, leave. One of the best metrics we have to gauge visitor involvement (and visitor dollars spent) is “Time on Site”. Yet, as we get more efficient delivering information, we eat into that number.

    Obviously we don’t want to make our sites more cumbersome, but there is a real need to engage visitors, which is why this idea of teasing is so intriguing. We spend a lot of real estate offering “related items” — what if we changed the language a little to invoke the users curiosity. Maybe have it read “5 related documents” instead of listing the 5 titles. Even little changes could have a big impact if you can find a way to tap into a basic human need.

    Excellent article. I look forward to reading more and experimenting with this subject!

  2. This is a great post. Well thought out, supported with research and references, and examples. It has substance. Thanks for the insight.

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  4. While I can’t agree with the notion that user actions can be ascribed entirely to behavioral responses to information gaps (the claim leaves out social action and communication, which are grounded in intersubjective understanding, and intentionality), I’m pleased to see a post on curiosity. I totally agree that withholding content, using navigation that is only partially complete, concealing or partially revealing content are all means by which to appeal to the user’s interests.

    We might attribute the mechanics of the call to action to this appeal, to story-telling and narrative forms, to communication, or to the simple fact that all of life is meaning produced out of ambiguity (which is also fundamentally meaningful, but prior to a selection or choice). Whatever may be the case, or the best explanation, design that engages by appealing to the user to select and finish — as you say close the gap — is more likely to involve and encourage user participation. By involving the user in completing the story we give them more to do. And insofar as interaction only occurs when the user acts on something, that engagement is paramount!

    There’s a deeper philosophical issue around associations (relationships between content elements, products, actions, what have you) — and which is more essential: similarity or difference. One could make the claim that similarity is difference (as long as the two things are not identical). Long tail arguments are based on the relatedness of elements — curiosity would seem to emphasize difference. Clearly, curiosity can be disappointed — and that would need to be addressed if curiosity were raised to a design principle (there’s little point in creating or using information gaps if the experience that follows on the basis of curiosity is ultimately disappointed: curiosity implies satisfaction of curiosity, and not just the unknown for its own sake). Relatedness would seem intended to satisfy, difference would seem to appeal to a user’s interest to learn or know more (and ultimately be satisfied?). And I’m not a huge fan of “satisfaction” as a design principle in all cases anyways — psychologically-oriented design principles in particular (we are not strictly rational choice actors but are indeed messy, incomplete, and interested). But I like that you emphasize designs that do not fully disclose, and which provide something requiring user action to be completed. Thanks for that!

  5. Dan on

    Reminds me of a blog post I wrote a while back

    Rewriting the textbooks (chapter 1 – Ambiguity rather than the obvious)

    Chapter 1 – Ambiguity rather than the obvious

    Usability 101 tutorials will make the point that any good designer/IA/UE worth their salt will always incorporate the principle of recognition rather than recall into their designs. This rule states that we should make objects, actions, and options easily recognizable and understandable and is surely based upon sound cognitive psychology research.

    However, I have done some research of my own and have made a very interesting discovery. I have uncovered that it is in man’s very nature to attempt to find answers to the unknown. I discovered this fact when roaming the Science Museum in an attempt to locate the Game On exhibition (The exhibition that examines the technologies that have revolutionised the gaming world, on from the 21st October 2006 to 25 February 2007). On route I noticed that I would tend to only stop at interactive kiosks whose functions and purpose were not immediately obvious to me. Based upon this elaborate research therefore I propose that we should rewrite the textbooks and replace the recognition rather than recall sections with a new rule of thumb, ambiguity rather than the obvious.

    It is simple really, if a UI design, or part of a UI design is ambiguous users will click, drag, hit and smash until they find out exactly what it is, how it works and what it does. Ambiguity therefore encourages exploration, and after all any good site (or any interactive medium for that matter) should be designed to encourage this, especially in the age of the possibility space and the world of 2.0.

    So I propose we embrace ambiguity with open arms and reject all that is obvious. Curiosity did kill the cat after all!

    (Disclaimer: this rule should be applied carefully, used within context and contrary to what this blog says is not actually based upon any sound cognitive research)

  6. @Nathan – I’m a bog fan of slight language changes that have a big impact on behaviors. Be careful though with the specific example you mention: “5 related documents” instead of listing the 5 titles. Thinking about “end caps” in a grocery store and exploratory behaviors, I often advise clients to expose the related stories. If interesting (and relevant), this bit of specific information (a specific title) will do more to arouse curiosity than the generic known of “5 related documents.”

    @Adrian – I hope I’m not suggesting “user actions can be ascribed entirely to behavioral responses to information gaps!” While curiosity may work in isolation, it’s a motivational tool that works best in conjunction with others nudges (social proof is a great pairing to almost everything!). I’m glad you mention storytelling and narratives– I’ve been toying with doing a presentation specifically on how to apply narratives to UX! The Lowenstein article I mention includes a reference to sense making and ambiguity aversion, which of course relates nicely to our natural tendency to make sense of things within the context of a good story, whether that story is shared or personal

    RE: being disappointed. That’s a risk with curiosity, and one that increases with the cost involved. I briefly mentioned this, but it warrants clarification: I’m often disappointed by the Netflix recommendation (bad rec or good rec for a movie I’ve already seen), but the cost is low– the “fun” aspect combined with low cost and sometimes good results makes it a net win for me. In the case of LinkedIn, the monthly membership fee is pretty steep and could result in dissatisfaction if the “revealed” information was not relevant or valuable.

    @Dan – There’s been some good research into curiosity and education. My impression is that educators (I used to be one!) should focus a lot more on arousing curiosity (vs disseminating information). Curiosity gets our attention and is linked with memory. For more on this, I recommend a section from the book Made to Stick (pages 80-87?? ) where a few such studies are cited. Regarding ambiguity, with exception to people who are naturally curious (trait vs state), the research I looked at does explore the relationship between how familiar (or unfamiliar) you are with a subject and how that affects curiosity. Basically, curiosity increases with knowledge– to a point. Some level of interest/familiarity in the subject is necessary for you to be curious in the 1st place. From there, studies show both (A) an increase, then decline in curiosity (where interest wanes) or (B) ever increasing curiosity and specialization as you learn more and learn more about what you don’t know…

  7. @Stephen Understood and agreed. I was trying to come up with an example off the top of my head, and that wasn’t a great one. It was a very clear article — I’d hate to have you think I missed the point entirely 🙂

  8. reinko on

    Thanks for a good article! Engaging examples and you’re right to remind us not to just deliver information efficiently. While I always ponder the many ways in which visitors can be triggered to go on, there is still much room for improvement in my concepts and many I see everyday.

  9. Great piece, and I think it curiosity is a tool that designers of all stripes should use, with caution. The news advertisements that run between 10:00 and 11:00 have become increasingly hysterical and manipulative (“Is what you don’t know about breathing causing harm to you and your children? We’ll have the latest at 11:00”) and then don’t pay off at all (story runs at 11:25 and is ungrounded hysteria-mongering). Not only don’t I trust the news when they tease me like that, I don’t trust any news that might possibly be teasing me. And I’m less likely to trust other sources as well. I’m becoming more media literate. The local news organizations feel it’s within their brand promise to tell stories like that, but it might not be within yours. It’s certainly not within mine.

    A friend that is always dropping bombs without just being direct with you is a friend that you stop calling.

    If you jerk me around, if you don’t pay off, if you require more work for me to interface with you that I really need, then I’m not engaged, I’m disengaged. I’m changing the channel, I’m not clicking, I’m not coming back. Don’t let curiosity overwhelm your authenticity.

  10. Steve, you’re absolutely right! I talk about a lot of different “nudges” we can use to influence behaviors (curiosity being just one of them). But as you point out, these can be overused in a particular context– the news being a great example (thought it still seems to work on lots of folks when it’s relevant!??). It doesn’t mean that these natural human behaviors can’t be called upon elsewhere in new contexts, but it does mean in that specific context, a particular approach might have lost effectiveness. Infomercials are a great example of a context that brilliantly leverages a number of persuasive techniques– and in doing so have become formulaic and lost all credibility. A similar thing is happening with all the sites copying LinkedIn’s percentage complete feature! The end result is of course distrust, ineffectiveness and/or loss of interest. It’s worth noting that in Berlyne’s model he does point out that “perceptual curiosity” loses effect with exposure (in contrast with epistemic curiosity). Now I’m going to contradict myself: you may have become media literate and I may have a natural distrust of any product marketed via an infomercial, BUT there’s still a huge market for whom these techniques are quite effective. And there are still a ton of people who haven’t yet encountered a “percentage complete” widget on their profile– for them it will all be new. And in the case of storytelling, knowing how to capture people’s interest is a timeless skill (though good storytellers know not to overdue anything). So, maybe the lesson is use in moderation and be aware of any contextual baggage…?

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  13. Randy Bynum on

    Interesting and stimulating article! Curiosity is definitely a gateway into expanding knowledge and, from my own personal experience, a much more lasting basis for learning.

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  18. Margaret on

    I recently came across your blog and have been reading along. I thought I would leave my first comment. I don’t know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


  19. Great article, I’ve applied the presented theory to share it by tweeting:

    “Click to find out why you have an uncontrollable urge to click this link >

    Wonder if it will work 😉

  20. Margaret on

    I recently came across your blog and have been reading along. I thought I would leave my first comment. I don’t know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.


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