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On Modelling in Memetics - Bruce Edmonds

5 Basic Selection Criteria for Memetic Models

It should be clear that what is needed is for such models to be chained into a complete explanation so that the presence of evolutionary mechanisms can be shown to cause the evolutionary phenomena that results. This would then justify the models that composed that chain. Note that this chain can (and probably will) be composed of more than one model. Even if one did have one model which seems to bridge the gap there would always be, at the top, the metaphor of evolution (that I talked about in
section 1) that it must relate to in order to justify its categorisation as a memetic model and the data model at the bottom.

It would be silly to insist that every paper must, by itself, bridge this gap, but what each model should (at a minimum) do is say how it explicitly relates to the models above and below itself in the chain. In other words, each model should be well verified and validated, as Scott Moss and I suggested for multi-agent models [17]. The validation of a model is where the structure of the model is based on the results of another model (even if it is fairly abstract like the idea of evolution). The verification of a model is where the results of the model are checked against something more definite (either the structure of other models that are themselves verified or a data model).

To make this clear let me take an example from a more established science: chemistry. Physics has models of the processes of elementary particle interaction*1; chemistry builds on this by positing mechanisms of how chemicals interact that use these physical processes (i.e validated) and verify these models against data models of real processes. Sometimes they then use these basic models of how chemicals interact in simulations which involve many chemicals when analytically solving to predict their interaction is too difficult. They may then make approximate numerical models of the results of these simulation and verify these against data models of real processes. The whole chain is illustrated in figure 10.

Figure 10. Validation and verification between layers of models in chemistry

Of course, beyond the mere presence of the validation and verification links, the strength of those links is also important. One method for helping to establish strong links is the use of formal models. Even if these formal models are not used to infer anything new they can be immensely useful in pinning down the meaning of terms and so reduce the potential for ambiguity and confusion. It is the bane of the social sciences, that everyone has slightly different meanings for key terms and concepts, and memetics is obviously no exception to this! A formal model allows the clarification of these meanings, so that the exact relationship between different models can be established. Another way of looking at this is that the links are themselves a sort of model, that are verified against the structure of the model they link: formal models thus allow the validation of these links against formal processes.

My characterisation of memetics in section 2, allows the categorisation a model as memetic, by the ultimate validation of its structure of against the evolutionary/genetic metaphor and the its ultimate verification against data from a process of cultural communication. These processes can be indirect using other intermediate models, as discussed above.

I wish to make clear that I am not criticising Calvin, Best or their work. A field will and must have specialists in different sorts of model. However the utility of their work will ultimately depend upon whether their models are included in a complete explanatory chain from theory to phenomena. Since memetics has only just began as a serious enterprise it is unsurprising that there is a lack of other convenient intermediate models with which to build these links, but this does not relieve us of the obligation to do so - a situation like economics where the excuse "its still a young science" is used 300 years after its inception should not be allowed. All models that are not part of a full explanatory chain should be mentally tagged as provisional and (at least temporarily) discarded if it is not justified in the near future.

This is, of course, a sort of bootstrapping process. In order to progress into a "normal science" (in Kuhn's terminology [14]) then we need to establish some complete explanatory chains as quickly as possible, so that more elaborate chains may be built with reference to these. To this end it would help if people in the field concentrated on domains where both the ultimate validation against the evolutionary metaphor and the ultimate verification against evidence of memes was as straight-forward as possible. Thus (at least until the shape and limitations of memetics becomes clearer) it would be far more helpful for studies in domains such as: bird song, nursery rhymes, tunes, and legal phrases in contracts where the mapping between the form and meaning of potential memes is clearly evident. Domains which involve very high level social constructs such as history or religion should be generally avoided since in these cases the construction of a convincing explanatory chain is the most onerous, and hence most suspect if used as support for a model.

On Modelling in Memetics - Bruce Edmonds - 18 AUG 98
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