Database of facts
Memory has both functions and facts, in effect part of memory is a database of facts. This data is classified; there is a very clear system that we all use to attach symbols that may be words, to collections of facts and images. We also appear to make a distinction between conceptual classes and occurrences. In these systems of classification we allow for the fact that any occurrence can belong to several classes.
Furthermore we also build up a very complex system of classes and relationships between classes.
This class based model, over time becomes extremely complex and effectively describes the system; I have excluded the occurrences in the following example because they simply confuse the diagram. The relationships are shown by named lines rather than boxes for the same reason.
So, sheep eat grass, grass is a plant, plants grown in fields, fields may support sheep and sheep live in fields.
In computer systems analysis work we use better and more precise diagrams called ‘Data models’ to deduce systems. From them we can deduce facts. So I know from this diagram that as grass is a plant then plants can be said to grow in fields. And because sheep eat grass and grass is a plant, sheep eat plants. This is logic – and all systems analysis work is actually based on pure maths and logic.
All deductive reasoning is based on traversal of models like these whether in computers or in your heads.
Here the classes are described using a word, but the concept need not be a word it could be an image.
In systems analysis work we make absolutely sure that we have a definition for the class, because without the definition, the model could be wrong.
The definition of a class is dependent on the sum of its functions.
And the functions are the system. For example.
What makes us a human being? The human being package functions – laugh cry, smile, sing, walk, talk, reason, some of which may be active in people some not, some of which may have been learnt some not. Thus to be a human being does not rely on all the functions being active at once, but it does rely on some of the functions being active and we should not have functions that a human being does not possess – if we have we are no longer human but some other class of being. If we can swim underwater for hours then clearly we are not strictly speaking human, because human beings don't have this function.
What makes a car, a car? – the car functions [accelerate, decelerate, corner, brake etc].
As we all know, there are tricky moments in all classification – when does one thing cease to be in one class and belong to another. Why should we call a lorry a lorry and not a car? It too can perform most of the functions of a car. The answer is that it has an extra function – the ability to transport goods usually in bulk, whereas cars serve only to transport passengers.
I don’t want to get into too much depth here the objective is not to teach you how to build computer systems, but to show how our mental models of data may be organised.
More details on how these mental models are used to get facts can be found in Memory - traversing the database of facts
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