Deporte escolar conectado con la programación de la Educación Física Escolar (EFE)

Perhaps the most influential early research on computer modelling of behaviour came from Roger Schank and his colleagues. Their initial motivation for representing human behaviour was to automate the analysis of natural language, particularly stories and

scenarios. In an early work, Schank ( 1 975) uses conceptual dependency theory (CD) to

analyse sentences and break down the meaning of words into primitive concepts such as 'physical transfer of possession' (encompassing such activities as giving, taking, stealing and buying) , and mental activities such as 'constructing new information from old information' (including deciding, concluding, imagining and considering). Although Schank was satisfied that at some level he could encompass the meaning of all words with these concepts there seemed to be a missing dimension. A frequently cited example is the concept of a kiss, which can be represented in CD by primitives showing the moving of two sets of lips so that they touch. However, the significance or

repercussions of such � act, which may be crucial in the development of a story, are not

One of the aims of Schank's subsequent research was to put the meaning of words and activities into human contexts. In conjunction with Robert Abelson (Schank and Abelson, 1977) he considers human beliefs, behaviour, goals and motivations. Since it has greatly influenced the approach used for the model in this chapter the relevant ideas as they relate to the current research will be presented here.

Human behaviour can be analysed at various levels and from different perspectives. At the highest level 'universal' human traits can be represented: that is, patterns of behaviour that can be assumed to be shared by the vast majority of humankind. For example, the assumption is made here that people will normally attempt to alleviate their own pain (physical or mental). Consideration of these general traits gives what Schank and Abelson call 'expectancy rules', a term coined byHemphill ( 1973).

Expectancy rules indicate how people are likely to react generally. A partial list of such rules is given in Figure 6.5.

1 . If a person's state becomes negative (either physically or emotionally) then that person will take action to attempt to improve the situation.

2 . If a person believes that his/her state (physical, emotional or mental) may deteriorate if nothing is done and taking some action may avert this then the person will carry out the action.

3 . If a person performs an action which causes a negative change in another person's state then the second person may perform another to cause a negative change in the first person's state.

4 . If one person performs an action which causes a positive change in

another's state on some level then that person may perform another action to cause a positive change in the first person's state.

Figure 6.5 Expectancy Rules (Schank and Abelson, 1977, p122)

The first rule deals with alleviation of a condition that is perceived to have deteriorated (for example, taking an aspirin to combat a headache). The second rule considers circumstances where the actor believes that things will get worse if nothing is done (for example, climbing a tree when being chased by a dog). Here, the aim is to ensure that the situation does not deteriorate rather than actually improving it. Rules 3 and 4 denote the classic revenge and gratitude scenarios, respectively.

Although everyone might have the same high level goals, we may have different perceptions of our current situation and may have different ways of achieving our aims.

Here is where individual aspirations and circumstances come in: what Schank and

Abelson call themes. Themes provide the main driving force for people's goals and

plans. They consider three variations: life, interpersonal and role themes.

Each individual will have some guidelines that influence his/her behaviour. These may be fostered by parents, assimilated as advice from others or developed as a result of experience. We inherit or develop attitudes that are used to determine how to behave in certain circumstances: honesty, aggressiveness, greed, courtesy. Life themes reflect each person's general attitude to life, aspirations, belief in how to achieve success and so on. These attitudes can often be encapsulated in maxims such as 'honesty is the best policy', 'do as you would be done by' and 'get rich quick'. A person will often have many of these guidelines that interact and that may interfere with one another. For example, a good way to get rich quick might be to carry out a robbery but an honest person may baulk at this possibility.

Schank and Abelson's classification of life themes is shown in Figure 6.6. personal quality: honesty, loyalty

ambition: success, getting a certain job

life style: luxury living, living frugally, travelling, being adventurous political attitude: anarchist, right wing, radical

approval: fulfil parent's expectations, be liked by women physical sensations: staying high, constant sex

Figure 6.6 Life themes (Schank and Abelson, 1977, p 148)

Although life themes influence people's behaviour when interacting with others, they will be tempered by their attitude and relationship to them. If we have a high regard for a person or that person has some hold over us then we may behave in a different fashion from when we dislike and can dominate them. Commonly occurring relationships include spouse, parent/child, mentor/acolyte, lover, enemy, boss/employee. Some of these may be mixed together. For instance, a son may be the enemy of his father, a boss may be a mentor of an employee. These are interpersonal themes and indicate attitudes to others and reactions to them.

Interpersonal themes help explain people's behaviour to others. They can be used to draw up expectancy rules for goals. For example, if A is in love with B then:

if C has caused h?flll to B then A may attempt to cause harm to C;

if B has a goal then A may promote this goal;

if B is not in love with A then A may attempt to change the situation.

It may be surmised how these interpersonal themes can impact on the general guidelines. For example, the last two expectancy rules in Figure 6.5 indicate how a person might behave to another as the result of some action (by taking revenge or showing gratitude). These reactions may be heightened, reduced or even negated by one's relationship to the person performing the original act.

At a more mundane level, a person's general behaviour may be guided by what job they have, what position they hold or what role they have taken upon themselves (doctor, garbage collector, nurse, president, burglar). This provides what Schank and Abelson call role themes. A person with a job has certain actions that s/he will take, certain things s/he will do. A person's role gives them a reason and justification for doing things.

A person's role is just one of many factors that governs their actions and may be over­ ridden by other considerations. A bank-teller may be persuaded to fiddle the takings from motives of greed. A waiter may, in anger, pour soup into a customer's lap. Lastly, a person may have several conflicting roles. The archetype of someone in this predicament is Pooh-Bah (in Gilbert and Sullivan's The Mikado) who holds a number of high offices of state:

' ... as First Lord of the Treasury, I could propose a special vote that would cover all expenses, if it were not that, as Leader of the Opposition, it would be my duty to resist it, tooth and nail. Or, as Paymaster-General, I could so cook the accounts that, as Lord High Auditor, I should never discover the fraud. But then, as Archbishop of Titipu, it would be my duty to denounce my dishonesty and give myself into my own custody as First Commissioner of Police' (Gilbert, 1992, p 1 1 ).

A person may aspire to become rich and how s/he does this may be affected by other themes. For example, if the person believes in honesty then some of the means of achieving this end, such as robbing banks or blackmailing, may be out of the question. An actor may be very environmentally aware and this may significantly affect their actions or goals. They may become a vegetarian or quit their job as an aerial topdresser. Thus there is much interaction between different themes and kinds of themes that has to be taken into account.

Once goals have been determined, means (plans) for achieving these have to be devised. This will involve a sequence of actions that will hopefully lead to the desired goal. Novel

plans have to be generated somehow: using means-end analysis (Newell and Simon, 1963; Emst and Newell, 1 969), for example. Other plans occur quite frequently and so do not need to be worked out from scratch. Schank and Abelson call these 'named plans'. A more elaborate form of this concept, called a MOP (Memory Organization Packet), is described in a later paper by Schank ( 1 982). MOPs are similar to scripts except that various intentions and expectations are built into the structure, enabling detailed feedback to be provided.

Although expectancy rules, themes and goals provide the background to determining the general inclinations of people as they interact, a blow-by-blow account of individual interactions is still required. Cause-effect chains can be used to generate plausible sequences of interactions. The kind of cause-effect phenomena that Schank and Abelson distinguish in human behaviour is not very different in form from that of device functioning. They list the kinds of transitions that might occur (Schank and Abelson, 1 977, pp25-27):

actions can result in state changes;

states can enable actions;

states can disable actions;

states (or acts) can initiate mental states;

mental states can be reasons for actions.

The last two often occur in sequence: a situation leads to a person taking an action. It is the basis of the planning idea: one considers the current situation and decides what to do. The above causal semantics (Schank and Abelson, 1 977) is at the bottom level in the progression of any session, guiding or monitoring the progress of the developing scenario. It can also be used as the basis of feedback in a systematic fashion as will be demonstrated later.

Although there will normally be some logic (rationale, excuse) for actions, these may be ritualized, based on convention, etc. This is where scripts come in. There have been various interpretations of the term since, but Schank and Abelson originally envisaged them as stylized sequences of expected events. They view them as giant causal chains where humans automatically fill in the missing steps. Steps can sometimes be justified in logical terms but, more frequently, just reflect 'the way things are done'.

When trying to understand someone's actions, Schank and Abelson suggest it is better to try scripts first since these are already worked out, and may contain conventional social practices etc that cannot be readily understood without a reasonable amount of real world knowledge.