Transcript
Page 1
Drawing an influence diagram can help you to think about situations where many different bodies, groups and individuals influence each other in various ways, and where perhaps you would like to influence the situation yourself.
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Blobs represent the entities which influence each other, and arrows represent the flows of influence between them.
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As with rich pictures, drawing an influence diagram involves a process of discrimination. If you include every influence you can think of, you'll end up with a tangled network of interconnected nodes.
The diagram becomes useful only as you identify the influences which are most significant in relation to your particular interest in the situation.
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The entities exerting or experiencing influence might be individuals or groups - or they could be other things which exert influence in the situation, such as culture, mood, legislation, salary levels and so on.
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The thickness of the arrow is generally used to indicate different strengths of influence.
You might use colour or line-style to represent specific types of influence, in which case you'd need to provide a key.
Or you might label an influence arrow, if the type of influence is not clear from the context of the diagram.
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As with all systems diagrams, it is the process, more than the product, which is of value. The process of mapping influence flows imposes a discipline on your thinking. This can help you to think more clearly about exactly how influence operates in a situation - and therefore about how you might act in order to most effectively influence the situation yourself.
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As with other diagram types, influence diagrams are tools for both individual and group thinking. Working on such diagrams in a group can reveal differences in perceptions, which lead to constructive discussions and new understandings. In both individual and group work, standing back and looking at what you have constructed can lead to unexpected insights about how best to take action in a situation.
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Drawn as part of a systemic analysis, the entities in an influence diagram may be regarded as components of a system of interest. So at some point - either before drawing the influence diagram, or perhaps as you begin to refine it - you will probably find it helpful to use a systems map to define a structure, purpose and boundary to your system of interest.
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In fact visually speaking, influence diagrams are just systems maps with added influence arrows. This may not be the most helpful way of regarding them though, because although there is a logical progression from systems map to influence diagram, if your primary interest is to do with influence, you might find yourself plunging straight into an influence diagram, and this focus on influence is likely to govern the way you define and structure the components of your system of interest.
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Thinking about the structure of your system of interest will lead you to think about the components which lie in its environment, and the nature of the influence they exert. In general, components are regarded as part of the environment of a system if they influence it in some way. So drawing an influence arrow from a component in the environment to the system boundary adds no information - to be useful it should show exactly which component within the system is influenced.
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As with a systems map, the diagram represents a snapshot of the situation at a point in time. It doesn’t show how the situation changes over time (and in particular, it is not used to show sequences of events or processes). The components are regarded as part of the structure of the situation, because they change only slowly relative to the time-span of the influences you are interested in.
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If you can lay out the diagram to show how the primary influences flow through your system of interest, you can begin to analyse how influence operates in the situation. For example, you might see a chain of strong influences, with just one weak link. Or you might notice a missing link in what would otherwise be a powerful flow of influences. Or you might notice the significance of an otherwise overlooked relationship.
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Three common mistakes in influence diagrams are using double-headed influence arrows, confusing flows of influence with sequences of events, and confusing flows of influence with flows of materials.
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Double-headed influence arrows are used to represent reciprocal influences of the same strength and type. Unless the two entities influence each other in exactly the same way, you should use two separate arrows, one headed each way.
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Sequences of events and procedures, or flows of materials, do not belong in an influence diagram. In a finished diagram they’re a sign of muddled thinking. Eliminating them from a working diagram is part of what’s helpful about using this diagram type to clarify your thinking.
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A final important distinction is between influence and causality. The next section covers multiple cause diagrams, and it is essential to distinguish these from influence diagrams. Visually, the diagrams are similar, and are generally distinguished by drawing blobs around the nodes of influence diagrams, but not around those of multiple cause diagrams.
In some cases a systems practitioner will draw an influence diagram before going on to work on a multiple cause diagram, and this is mentioned in the T552 text. However some systems teachers have observed that this is an unhelpful connection to make in the mind of a new practitioner. There is an intuitive connection between the two: 'I want to influence someone because I want to cause something to happen'. But the two are very different: they don’t map onto each other.
Influences are part of the structure of a situation. They exist at a point in time between entities - things. They may possibly lead to change, but they don’t represent that change.
Cause and effect belong to process. They operate over time, and represent the mechanisms by which change takes place. The nodes in a multiple cause diagram represent states and events, rather than things.
Having said that it can, on occasion, be difficult to distinguish between the two. For example, mood, which I mentioned earlier, could be regarded as an entity which influences a situation, or as a state which is caused and which has effects. It might appear in either diagram type. Ultimately what distinguishes your choice of diagram type is the type of situation, and your interest in it. If you’re interested in the direction of political influence, use an influence diagram. If you’re interested in the mechanism by which change occurs, use a multiple cause diagram.