Mental models, and the Other as dark reflection.

By Gordon Rugg

This article is the first in a series about mental models and their implications both for worldviews and for everyday behaviour. Mental models are at the core of how we think and act. They’ve received a lot of attention from various disciplines, which is good in terms of there being plenty of material to draw on, and less good in terms of clear, unified frameworks.

In these articles, I’ll look at how we can use some clean, elegant formalisms to make more sense of what mental models are, and how they can go wrong. Much of the classic work on mental models has focused on mental models of specific small scale problems. I’ll focus mainly on the other end of the scale, where mental models have implications so far-reaching that they’re major components of worldviews.

Mental models are a classic case of the simplicity beyond complexity. Often, something in a mental model that initially looks trivial turns out to be massively important and complex; there’s a new simplicity at the other side, but only after you’ve waded through that intervening complexity. For this reason, I’ll keep the individual articles short, and then look in more detail at the implications in separate articles, rather than trying to do too much in one article.

I’ll start with the Other, to show how mental models can have implications at the level of war versus peace, as well as at the level of interpersonal bigotry and harrassment.

The Other is a core concept in sociology and related fields. It’s pretty much what it sounds like. People tend to divide the world in to Us and Them. The Other is Them. The implications are far reaching.

The full story is, as you might expect, more complex, but the core concept is that simple. In this article, I’ll look at the surface simplicity, and look at the different implications of two different forms of surface simplicity.

It’s a topic that takes us into questions about status, morality, and what happens when beliefs collide with reality.

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Crisp and fuzzy categorisation

By Gordon Rugg

Categorisation occurs pretty much everywhere in human life. Most of the time, most of the categorisation appears so obvious that we don’t pay particular attention to it. Every once in a while, though, a case crops up which suddenly calls our assumptions about categorisation into question, and raises uncomfortable questions about whether there’s something fundamentally wrong in how we think about the world.

In this article, I’ll look at one important aspect of categorisation, namely the difference between crisp sets and fuzzy sets. It looks, and is, simple, but it has powerful and far-reaching implications for making sense of the world.

I’ll start with the example of whether or not you own a motorbike. At first glance, this looks like a straightforward question which divides people neatly into two groups, namely those who own motorbikes, and those who don’t. We can represent this visually as two boxes, with a crisp dividing line between them, like this.

However, when you’re dealing with real life, you encounter a surprising number of cases where the answer is unclear. Suppose, for instance, that someone has jointly bought a motorbike with their friend. Does that person count as being the owner of a motorbike, when they’re actually the joint owner? Or what about someone who has bought a motorbike on hire purchase, and has not yet finished the payments?

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Explosive leaf level fan out

By Gordon Rugg

Often in life a beautiful idea is brought low by an awkward reality. Explosive leaf level fan out is one of those awkward realities (though it does have a really impressive sounding name, which may be some consolation).

So, what is it, and why is it a problem? Can it be a solution, as well as a problem? These, and other questions, are answered below.

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Pattern matching

By Gordon Rugg

Note: This article is a slightly edited version of an article originally posted on our Search Visualiser blog on May 17, 2012. I’ve updated it to address recent claims about how Artificial Intelligence might revolutionise research.

So what is pattern matching, and why should anyone care about it?

First picture: Two individuals who don’t care about pattern matching (Pom’s the mainly white one, and Tiddles is the mainly black one (names have been changed to protect the innocent…)


Pattern matching is important because it’s at the heart of the digital revolution. Google made its fortune largely from the simplest form of pattern matching. Computers can’t manage the more complex forms of pattern matching yet, but humans can handle them easily. A major goal in computer science research is finding a way for computers to handle those more complex forms of pattern matching. A major challenge in information management is figuring out how to split a task between what the computer does and what the human does.

So, there are good reasons for knowing about pattern matching, and for trying to get a better understanding of it.

As for what pattern matching is: The phrase is used to refer to several concepts which look similar enough to cause confusion, but which are actually very different from each other, and which have very different implications.

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Why Hollywood gets it wrong, part 3

By Gordon Rugg

The first article in this short series examined how conflicting conventions and requirements can lead to a movie being unrealistic. The second article explored the pressures driving movie scripts towards unrealistically high signal to noise ratios, with few of the extraneous details that occur in real conversations.

Today’s article, the third in the series, addresses another way in which movies are different from reality. Movies depict a world which features the word “very” a lot. Sometimes it’s the characters who are very bad, or very good, or very attractive, or whatever; sometimes it’s the situations they encounter which are very exciting or very frightening or very memorable; sometimes it’s the settings which are very beautiful, or very downbeat, or very strange. Whatever the form that it takes, the “very” will almost always be in there somewhere prominent.

Why does this happen? It’s a phenomenon that’s well recognised in the media, well summed up in a quote attributed to Walt Disney, where he allegedly said that his animations could be better than reality.

When you think of it from that perspective, then it makes sense for movies to show something different from reality, since we can see reality easily enough every day without needing to watch a movie. This raises other questions, though, such as in which directions movies tend to be different from reality, and how big those differences tend to be.

That’s the main topic of this article.


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Intrinsic, extrinsic, and the magic of association

By Gordon Rugg

As regular readers of this blog will know, I have an awed respect for the ability of Ancient Greek philosophers to spot a really important point, and to then produce an extremely plausible but only partially correct explanation, sending everyone else off in the wrong direction for the next couple of thousand years.

Today’s article is about one of those points, where the Ancient Greeks didn’t actually get anything wrong, but where they laid out a concept that’s only part of the story. It involves a concept that can be very useful for making sense of consumer preferences and life choices, namely the difference between intrinsic properties in the broad sense, and extrinsic properties in the broad sense.

Here’s an example. The image below shows a pair of Zippo lighters. One of them is worth a few dollars; the other is worth tens of thousands of dollars, even though it’s physically indistinguishable from the first one. Why the difference? The answer is below…

zippo banner

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Things, concepts and words

By Gordon Rugg

There’s a useful three way distinction in linguistics between things, concepts and words.

This article is a gentle examination of the distinction, with some thoughts about implications for human error.

Unicorns and non-unicornsbannerSources for images are given at the end of this article

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