What Is Your Mental Model?

Posted by

B&A readers get 10% when purchasing from Rosenfeldmedia.com (use code BARMMM10)
Rosenfeld Media has just released Indi Young’s Mental Models: Aligning Design Strategy With Human Behavior. Boxes and Arrows sits down with Indi to talk about:
* The origins and evolution of the mental model
* How the mental model is a way of visualizing nearly any research data
* What shortcuts you can use to get started on a mental model with minimal time investment
* Why “combing” an interview is like riding a bicycle
* How Webvan failed because it ignore the mental model of its customers

If you’re unfamiliar with Indi’s mental model diagrams, download the excerpt(.pdf), check out the “book’s description”:http://www.rosenfeldmedia.com/books/mental-models/info/description/ for more information on the method, or visit “this Flickr set”:http://flickr.com/photos/rosenfeldmedia/sets/72157603511616271/ for images from the book.

Discount for Boxes and Arrows readers: Get a 10% discount by purchasing the book “directly from Rosenfeld Media”:http://www.rosenfeldmedia.com/books/mental-models/. Just use the code BARMMM10.

Mental Models: Origins & Evolution

Boxes & Arrows: Our readers would benefit from the story behind the Mental Model. Can you tell us how you created it?

On a project at Visa back in ’93 or ’94, I was the interaction designer on a team of consultants including developers, business people, and analysts.

The business analysts didn’t have their work together, so I started working on the customer service rep workflow table in MS Excel, a kind of state diagram from “Computer Science”:http://en.wikipedia.org/wiki/State_diagram. At the same time, a Stanford professor did a presentation on the layers of user experience at “BayCHI”:http://www.baychi.org/. One of those layers was a “task” layer, very much like the state diagram.

At first I only documented the the behaviors; I didn’t let any of the emotions or philosophy get into it at all. For one client, I presented the state diagram by lining up the internal workflow underneath their customers’ workflow, the flip of the mental model. Kevin George was there and immediately encouraged me to pursue this method as it was a very powerful way to explain these relationships to a customer.

B&A: It’s interesting how this really arose from trying to allow communication between stakeholders. How has the mental model changed since then?

I did some projects at Charles Schwab, and started using the long horizon diagram. In doing that format, I started realizing that I was trying to capture motivations that influence behavior as well as the behavior itself. I was never interested in the granularity about how you actually use an application that the usability people were seeking. I wanted to know understand what you’re thinking about.

Figure 1: A mental model diagram (click to enlarge)

Figure 1: A mental model diagram (click to enlarge)

“Todd Wilkens”:http://adaptivepath.com/aboutus/toddw.php mentioned a year or two ago that I am looking for behavior, and I realized that they weren’t tasks. He was absolutely right.

These days I’m trying to call it behavior, motivation, philosophy, and emotion but stay away from statement of fact, references to things, preference, and the actual use of the tool. I want to know what people think as they walk down the hallway to go do something. I call this the hallway test.

Customers are just thinking about their reactions to the tool. They are not trying to squeeze water out of a water bottle, they are trying to quench their thirst. Of course you want to listen to them, but at the same time you want to interpret.

They aren’t going to approach you and say, “I’m trying to quench my thirst, make it quench faster.” When you try to do it at the level of the tool, you’re blinkered by what that tool does already. I’m interested in the mind process – what you are you trying to get done.

B&A: This doesn’t acknowledge the base influences that are going to make that successful or not. As a business, you have an objective you’re going for and need to balance it with the customer’s objective, not their preference. Even business decisions are many times colored by preference.

I like to talk about how CEOs and founders for startups have the original mission statement at heart. “I do this because my son is having trouble in school, because the school system doesn’t work.” They sometimes lose sight of all the details.

They start off down the path with one certain solution, they’re solving the problems associated with that solution and losing track of the mission. What if it’s the wrong path? What if they branched left when they should have branched right?
They start losing the ability to go back and explore other branches or go back to the root and start in another direction because they have so much investment in it.

B&A: Interesting. What you’re doing is taking a mission statement and giving it a skeleton to grown on, to iterate a strategy. The mental model includes the details of what both the business and the customers are trying to do. Is that right?

Yes, the diagram looks like a skeleton or a spine if you turn it on its side. That’s the whole idea! It’s something that’s going to last for a very long time, and you can hang all of your decisions off of it. It’s something that you want to go back to on a regular basis when you want to start a new path or shake things up.

The diagram also helps you show others how you’ve prioritized your current focus and how their item fell into the quadrant of things that you’ll do later.

Comparing Methods

B&A: How do mental models compare with different research methods?

Many different methods allow you to collect data, but I have not found others that let you represent the data effectively. The mental model diagram can visualize ANY research data as long as it’s data about why customers do things.

For example, diaries can feed into mental models. You can process them the same way you process a transcript. You won’t be able to drill down into the “why” further, as you have no control how deep people go.

Ethnography (field studies) can also get built into a mental model. Once you’ve followed people to their offices, you have third-person notes (she did this, he did that) rather than transcripts. Just translate it to “I” and make a mental model.

At “Adaptive Path”:http://adaptivepath.com/, when we were asked to do usability, we’d run an interview either the first part of the last half of the test. Then, we would add the interview data to the mental model as well.

Just get this information somehow. What is going on in their head before they use the product? Why are they using the product? How are they using the product isn’t that important. Ignore the product.

B&A: So you just do some research and dissemble it into the mental model. They aren’t mutually exclusive.

That’s why I have all these shortcuts and why anyone can create a mental model. It’s just a representation of a process, and the purity of that representation is dependent on how much time you put into it.

That purity arises from how much you can disengage yourself from your own world and tools. Look at the user from their perspective.

Creating a Mental Model

B&A: Ok, let’s shift gears a bit. You go do your interviews. Can you talk about extracting the behaviors, what you call “combing” the script? You were saying that sometimes it’s difficult.

It is hard to do a mental model, until you get it. As I mentioned, this is not just tasks. It’s behavior, motivation, and philosophy. You have to think about how to distinguish preference from philosophy and statements of fact from actual behaviors.

Here’s an example:

When interviewing a manager who oversees fleets of vehicles, she might say:
“I believe in not overloading my employees with work.”
“I’m gonna assign 3-4 jobs per day.”
“We send out 300 vans a day.”

These words come to me as 3 things:
* Assign 3-4 jobs per day. This is a true task.
* Not overloading the drivers. This is a philosophy that guides how the jobs are assigned.
* Send out 300 vans a day. That is just a statement of fact that I will not include in the mental model.

Sending 300 vans out sounds like a task. It has a verb, but it’s not a task. You aren’t doing it, the organization is.

They can talk about the process of how they decide where to send the drivers, prioritize things, or deal with emergencies. All of that is behavior. It can be difficult for designers to sort between those at first.

You also want to leave preferences out of the diagram. They actually began with the verb “prefer.” “I prefer to come into work early.” In his next statement if a driver told you his philosophy behind coming into work early “because…” That is what you want. If you picked that up during the interview, you could have explored it a little bit. There may or may not be a reason. Maybe he’s just a morning person.

Philosophies are important to get into the mental model because your business is going to want to be aware of and support those kinds of things.

B&A: There’s a subtlety there. Both statements sound like descriptions of why they do something. One has a reason, the other is just what they like or don’t like.

Not only is it difficult when you’re trying to comb tasks out of a transcript, but it’s also something that poses difficulties when you’re writing the interview. Before you try running an interview, you have be somewhat aware of what the tasks are going to be. A great way to do that is to practice combing a transcript.

Be careful that you don’t ask leading questions using do, did, would, or could. Rather, start with who, what, where, when, and how. If you do this, you’re generally scott free. And always remember to follow up by asking why, like a 4-year-old. It may be annoying, but that’s kind of what you’re trying to do.

Even with all of my experience doing this, I still find myself not going deep enough. One blatant example: one woman told me that she holds meetings with her team every week. In my head, I made this instant assumption of what those meetings were about, because i’ve been to weekly meetings with a team leader.

When I was combing it, I thought, “Why is she holding those weekly meetings? Is she trying to…?” The assumption I made was that she was trying to find out status on everybody’s project. In the end, I had no idea why she was holding those meetings.

A lot of these interviews that I do are a little more psychoanalytical, because it is not conscious why were doing some of these things. Maybe the woman holding the meeting has never had to enunciate why she’s doing it. I ask her to do that during the interview.

B&A: In the “Women in IA podcast”:http://iavoice.typepad.com/ia_voice/2007/04/women_in_ia_ind.html, you mentioned that you don’t find it difficult to get people do to mental models. I have to press on that fact. It’s not a very simple, easy process.

Well, let me go back to the shortcuts. You and i could sit here in Starbucks (where we met for the interview – Ed.) and sketch out what the baristas do. If we watched them greet the regulars and non-regulars, we could sketch out their tasks and mental processes. There is a real strong mental model right there. We could note what we see, but we’re going to miss things. For example, we won’t capture what they do in before opening the doors in the morning.

You don’t necessarily have to do it the hard way – going out, doing the interviews, and combing the transcripts for tasks. However, that’s the most agnostic and data-driven way to do it, and by going through the extra effort is how you’re going to make discoveries of things that aren’t already in your head.

I list a couple options in the book. For example, you really believe in this, but your employer doesn’t. Well, I’ve heard people interviewing people and combing the interviews and creating a mental model in their spare time. Then they unveil it in some team meeting to kisses and hugs.

B&A: It just sounds like that will be a little more focused on the tools that exist rather than the philosophies around them.

That’s the problem. All of these shortcuts have the same troubles. I actually ran a lot of the “stakeholders around the table” discussions back in the dot com era because every wanted to spend the time to doing it.

I even did this for Webvan, but I could not get them to pay attention to it. For example, their interface was about picking delivery windows, which made the customer pick the end of the transaction up front so the company could maximize the efficiency of the trucks going out. It just wasn’t working.

Customers didn’t like picking the delivery window first. It wasn’t in their mental model. “I want to tell you what I want, because that’s what I know now. Then we can discuss how you bring it to me.”

Every single one of the Webvan mental models was missing the mental spaces that would have gotten them ahead of their competition or help them understand their customer base. So the “sitting around the table” method is a little dangerous, as it might mislead you to believe you’ve got it all.

B&A: Luckily for those of us still standing, we can try to avoid those mistakes. Mental models seem like fantastic tools. Thanks so much for taking the time, and good luck with the book!

I enjoyed it, too. Take care!


If you liked this interview, download the excerpt. (.pdf)

Boxes and Arrows readers can get a 10% discount by purchasing the book “directly from Rosenfeld Media”:http://www.rosenfeldmedia.com/books/mental-models/. Just use the code BARMMM10.

About the Book
“Mental Models: Aligning Design Strategy With Human Behavior”:http://www.rosenfeldmedia.com/books/mental-models/
by Indi Young
Paperback, 299 pages
Publisher: Rosenfeld Media (2008)
ISBN-10: 1933820063


  1. Great interview – looking forward to the book.

    One issue I would have liked to see discussed in the interview is terminology. Indi’s use of the term “mental model”, as a set of behaviours and goals independent of a particular system, seems to be quite different from the traditional definition derived from cognitive psychology and popularized in HCI/UX by Don Norman et al. In a field that’s already plagued by a lack of consensus on matters of terminology, this double usage seems like a less than optimal solution.

    Also, it’s not clear from the interview whether Indi’s mental models are intimately tied to the “fishbone diagram” visual representation. Presumably the same information can be visually represented in other ways (e.g. as an affinity diagram). If that’s the case, does it still qualify as a mental model?

  2. I’m trying to see what’s new here. Isn’t this just a way of visualising the data from a hierarchical task analysis?

  3. Thanks for the comments! (I’m Indi, the author of the book.) Yes, this is a way of visualizing data, and it is “a very powerful way to explain these relationships to a customer.” It also keeps the designer focused on the user, not the product. Many companies still design iteratively based on how well an existing product works, which is fine, but it doesn’t give you a wider perspective.

    As far as the term “mental model,” in the past decade cognitive scientists have broadened the meaning again and again. I felt that this representation of data falls within those broader definitions.

    The “fishbone” (or “spine” or “horizon”) diagram is key in that it shows alignment between the things a person is doing and the ways an organization supports it. So the alignment is the important bit. Above or below the line the representation can take any form. I’ve found that three hierarchical levels of affinity are the right amount of data to depict.

  4. Indi, we’ve found this technique very valuable at Vanguard – ever since I saw you and Peter present it in workshop form at Jared’s UIE conference years ago. I’m really excited to see that it has evolved over time to include aspects of the user experience such as emotion, motivation and philosophy – can’t wait to get the book and dig deeper!

  5. Indi, I had been inspired by your Keynote at the Adaptive Path UX intensive in DC last year. What I took from that keynote helped me define some better approaches as a practicing IA for Thermo Fisher Scientific and now for sunKING Digital. I have added to your mental model structure by introducing the development row/needs as a compliment to your framework. What this has done, has introduced any IT limitations up front in the discovery phase. It also help define better the high-level business requirement document since it is now better rooted in realistic technology interactions. Just wanted to add to your great work. Your process has defined my process greatly. Thanks!

  6. great storytelling; i ordered the book

    when i give seminars to people more on the client side than the practitioner side — ie, what is a user flow — i have them draw the steps for making toast

    when we get to the point in the discussion where i ask how far back should we go — to the grocery store where you got the bread, to the farm where the wheat was grown, or to the multiple times and places in pre-history where agriculture was invented, the lights blink on brighter and brigther.

  7. Very, very cool. Mental models aren’t a tool I’ve used before but I will definitely order the book and learn more. Thanks.

  8. I’m sure this book will be an excellent resource. I can’t wait to get into it.

    I’ve often wondered how audience segmentation plays into or serves a purpose as a companion to mental modeling. Specifically, do you recommend creating different mental models for different audience segments, or do you roll the behaviors, motivations and needs of all relevant audiences into a single, all-encompassing mental model (perhaps somehow earmarking audience crossover using icons/colors within the mental model?).

    Does anyone have thoughts on this question, or is this in any way addressed within this new book? Thanks.

  9. @Aaron

    Great question about segments. The mental modeling process approaches segments based on tasks (what people do and how they think), rather than by demographics or psychographics. I’ve seen this in action, and it’s incredibly interesting.

    The book goes into detail about how when you are first getting the mental model process started, you should first make hypotheses about what these segments will be. Then, once you’ve done the research, come back and see how well your hypotheses have borne out. It’s quite an interesting process and will change the way you look at your segments.

  10. am loving the book Indi.. really great work! (especially like that I can read it *now* in a pdf too)
    I’d been looking for something that’d help communicate this type of understanding with stakeholders and (more importantly, I think) internally in the team. We’d used concept models a bit in the past, but were having issues in the way they bled over into different perspectives of an experience. After reading the first couple of sections of your book today I’m pretty excited about trying this out. Thanks for sharing your insights & experiences with us!

  11. What a great article. Mental models are a tool that I don’t use very often. I do find them very helpful to process and will be integrating them into my work more often now!

  12. While I generally feel we do the right thing wihtout a Mental Model, I lke the idea that it’s both justifying to stakeholders and a good checkscheme at the end of a project. Ideal.

    I’m having trouble finding a good program to build them with. Does Indy recommend/provide a tool in the book?
    Or do we resort to blue boxes in Visio?

  13. Hello,
    I am an architect, a teacher, and a researcher interested in design thinking, and design education. I am eager to read the book, but in the meantime I would like to ask how Mental Models can help me to gain insight in the way students design, or how to develop better teaching strategies in the design studio.
    As you see, I am not as much interested in the client-architect relation, as in the design teacher – student relationship. I will be very thankful if you could give me advise in this respect.
    Best, and look forward to hearing from you.

  14. Indi, I’ve been a fan and practitioner of mental models for doing UX design – both when I was consultant and now working in-house as a UX manager at Symantec. So I was excited to see your book, and just bought a copy.

    But recently I’ve been getting my head around a different aspect of mental models and mental maps – related to your examples from Visa and Webvan. It’s about mental maps of people within organizations and how people learn and unlearn.

    This is a quote from “How Organizations Learn and Unlearn,” from the Handbook of Organizational Design (Oxford, 1981):

    “Learners discover themselves and their environments; these discoveries lead to comprehending of reasons beyond events, and ultimately to mental maps of relevant aspects of the environment…. Learning thus encompasses the processes whereby learners iteratively map their environments and use their maps to alter their environments.”

    Like your example about the gap between the mental maps of Webvan’s stakeholders and their end-users’ mental maps – around scheduling delivery windows – one of the keys to working with stakeholders is facilitating unlearning or relearning. But it’s a big challenge to try to change organizational myths and the way companies understand their environments and their customers.

    If you see this post, I’d love to hear your thoughts on ways that you go about closing gaps between stakeholders’ mental models and those of their end-users and customers.


  15. Hello, I’m Dede Wiweka
    I am loving the book Indi Its different from the traditional definition derived from cognitive psychology. I’m sure this book will be an excellent resource. Mental models aren’t a tool I’ve used before but I will definitely order the book and learn more. Thanks

Comments are closed.