9.6 Sign graphs
Next, in the exercising of your diagramming skills, I want to look at sign graphs. Unlike the three diagram types you have already drawn, a sign graph is not usually used to structure the understanding of complexity. This means it is likely to be relatively less useful in the task of searching for system within the complex situation described in the case study. Sign graphs can, however, be useful once some elements of system have been identified. They can support the exploration of how a system works. Although drawing a sign graph will not necessarily contribute to the main task of structuring the complex situation, this is a good opportunity for brushing up your skill in drawing them.
Sign graphs can help sort out how and why variables in the system change. A good way into such a diagram is to identify some variable, either from the text or from your rich picture. You can then explore other variables that drive that variable. Within the case study, I noticed ‘contributions collected from absent parents’ as a possible variable worth exploring. It caught my attention because it seemed to represent an implicit measure of the CSA's success, or lack of it. A sign-graph would help to discover the influences that would increase the amount of contribution collected and those that decrease the contributions. You could either use ‘contributions collected from absent parents’ as a starting point or identify a variable of your own choosing.
Expect to take about 20 minutes on this activity. Allow longer if this is your first sign graph.
Use a sign graph to explore the relationships between variables within the case study.
Chose a variable to use as a starting point. Identify the variables that influence that variable and whether they have a plus-sign effect or whether they have a minus-sign effect. Be careful to use the signs correctly.
As well as the variables that affect your starting-point variable, include the variables the starting-point variable affects. Are there any feedback loops? What are the overall effects of changes in some of the key variables? Aim to have between 7 and 12 variables in your diagram.
Make a note of any insights your diagram generates, either about the case-study situation, or about the processes of diagramming.
Take the necessary steps to evaluate your diagram.