Sunday, 5 July 2015

Intentional Systems Theory and HCI

Intentional Systems Theory

Intentional Systems Theory is a theory about how we understand and predict the behaviour of different sorts of systems. It suggests three different approaches, or 'stances', to predict the behaviour of systems. Having a rough understanding of these stances is a useful aid in understanding how people understand different systems.

The Physical Stance - the physical stance is based on physical laws. For example, we predict what will happen when something is dropped based on our understanding of gravity. We predict where water will go, and how balls on a snooker table will move using the physical stance.The physical stance is in a sense the 'truest' stance, and in principle the behaviour of any system should be describable using it, but for many systems it is not a practical approach.

The Design Stance - the design stance is based on assuming design in a system or artefact. For example, when figuring out a novel artefact believed to be an alarm clock, we don't try to understand it in terms of physical laws or even circuit diagrams. We make design assumptions; such as an alarm clock will have some way of setting a time for the alarm, and at that time it will do something (such as making a noise) that has a reasonable chance of waking us up, and so on. With the design stance we assume an artefact has a purpose, and we figure out how it should be used to fulfil that purpose.

The Intentional Stance - with the intentional stance we assume that something can be usefully predicted as though it had a mind complete with things like beliefs and intentions, and that it will act rationally based on what is in its mind. This is how we interact with other humans, and how we understand the behaviour of animals. We don't know that Fido and Rover (who are dogs) have a mental life anything like ours, but by assuming they have things like beliefs and intentions and that they will act rationally on them, we are able to predict their behaviour.

Using the Stances to Understand Systems

The intentional stance can be usefully applied to things like computers and robots, and frequently are. Trying to predict the behaviour of a rock by thinking about what beliefs it has will get you nowhere. Assuming the moon is designed and has some purpose doesn't yield any insight into its future orbits. Similarly, people don't feel betrayed by rocks, or that the moon doesn't like them.

In contrast thinking of a computer opponent in a game as being an intentional system is useful: your opponent has an intention to kill your game character; you can assume it has beliefs such as your current location; it may even be trying to guess where you will go next; and, it will act rationally within its means to meet its goal of hunting down and killing your character.

The different stances provide insight into how people react emotionally to different systems and artefacts. One cannot really be angry with an artefact considered with the physical stance. In the case of the design stance, you can be angry at the designer of an alarm clock, annoyed at yourself for not using it properly, and frustrated when it doesn't work properly, but you can't be angry at the clock, or feel betrayed by the clock. People can (and do) feel betrayed or let down by computer game characters, and even devices like smartphones. (This may get worse as they take on human-like characteristics with their embedded personal assistants).

The three stances are useful ways of thinking about different systems, and in understanding how other people think about things in the world.

The Stances and HCI

When designing a user interface the goal is to provide the user with something that allows them to usefully understand and successfully interact with the system. The user interface does not need to be like the system it is for, it can be a fiction (or 'user illusion') that provides a simple or intuitive model of the system to make it easier to use. The three stances provide a designer with three distinct approaches to designing a user interface. The designer should select the most appropriate stance for each element, or for the overall interface, depending on how the product should be used.

A user interface using the physical stance will include features that encourage the user to think in terms of physical systems. Physical controls like joysticks and mice that create a corresponding movement in the system when the user moves their hand are an example of physical stance interface elements. Another example would be a touch-device that supports 'swiping' between different views in a way that corresponds to moving and manipulating physical artefacts. Users explore physical stance systems and discover ways of using them.

User interface elements that use the design stance will have features that are 'like' other design stance artefacts, they will suggest purpose to the user, and intended use. The user will identify features of the user interface (buttons, controls, etc) that look like they are supposed to be used in a certain way, toward a certain goal. Logical and sequential grouping of controls will help to emphasise the intended use. Users learn how to use design stance systems.

Systems that use the intentional stance promote discourse, affect, and human-like (or perhaps animal-like) interactions. These systems exploit a pre-existing system model that users have (i.e. of a mind, or mind-like thing). Such systems can focus on the pre-existing model of interaction, and build upon it. However, while a model of a design stance system can be made explicit and specific to the designer's needs, to an extent the gross model properties of an intentional system may be fixed. Users engage with and enter a discourse with intentional systems.


This article undoubtedly draws on: Dennett, D. (2011) Intentional Systems Theory, in The Oxford Handbook of Philosophy of Mind, (eds. McLaughlin, Beckermann, and Walter). Oxford University Press.

The Darkness That Comes Before

Some quotes:

"...though he consorts with man, woman, and child, though he lays with beasts and makes a mockery of his seed, never shall he be as licentious as the philosopher, who lays with all things imaginable"
"Children questioned as much to be rebuffed as to be answered, as they must in order to learn which questions were permissible and which were not."
"We seek absolute awareness, the self-moving thought. The thoughts of all men arise from the darkness. If you are the movement of your soul, and the cause of that movement precedes you, then how could you ever call your thoughts your own? How could you be anything other than a slave to the darkness that comes before?"

From Scott Bakker's The Darkness That Comes Before: Book 1 of the Prince of Nothing. 

Materialism (Equivocations Episode #1)

The word materialism has multiple meanings that can become confused (sometimes deliberately). Materialism can mean (roughly): the philosophical view that all that there is, is made up of energy and matter, and by understanding the laws of how these things interact we can (in principle) gain an understanding of how the universe works. I'll call people who hold this view materialists. Materialism can also mean (roughly): an excessive focus or valuing of material goods, i.e. jewellery, cars, fashion items, etc. I'll call people who this term applies to materialistic.

By giving these views separate labels it is clearer to see that they are distinct views. A materialist might prefer to leave an austere life, forsaking material wealth, and focusing on matters of spirituality and love. There is no reason to suppose that a materialist is materialistic. Similarly, someone who is not a materialist, say a Christian who believes in souls and a heavenly realm, would not be a materialist as they believe in more than a material universe. They could however be rather materialistic. While not all Christians are materialistic, it is quite clear that many can be and are.