some thoughts about design research
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This document discusses theoretical models used in ordinary research to understand phenomena, and artefactual models used in design research to develop artifacts that control targeted outcomes. Theoretical models use vocabulary, rules, and generalizations to describe and predict behaviors, which are tested against real-world observations. Artefactual models describe how artifacts will behave based on relevant theoretical models and untested assumptions, and are tested through simulations and empirical tests. Both aim to improve models and control the world, with design research focusing on developing useful artifacts.
some thoughts about design research
- 1. Some thoughts on design research, models and simulations Peter Sloep Friday, May 4, 12
- 2. Overview Part I: ordinary research, the essentialia Part II: design research, the differences Part III: models Friday, May 4, 12
- 3. Caveat A quick and dirty introduction to some aspects of the philosophies of science and technology Sometimes less than accurate, sometimes plain wrong, but always in an attempt to be useful. Friday, May 4, 12
- 4. Ordinary research, aimed at understanding and control Friday, May 4, 12
- 5. Theoretical models Ia Ib S1 S2 S3 Ic Friday, May 4, 12
- 6. Theoretical models smoke therapy Ia Ib S1 S2 S3 healthy Ic cancer dead therapy Friday, May 4, 12
- 7. for a model to be useful, you need descriptive apparatus, vocabulary rules for how to use it, grammar, syntax rules that uses the vocabulary and syntax to describe possible model behaviours Friday, May 4, 12
- 8. rules about possible behaviours are interesting they are generalizations, subsume instances of model behaviour form: whenever X then Y Friday, May 4, 12
- 9. all kinds of vocabularies and syntaxes math.: diff. equations, 鍖nite automata, probability calculus computer languages: Stella, Netlogo ordinary language (but formal languages are much more powerful because they allow inferences from axioms) Friday, May 4, 12
- 10. What use are models? Are the generalizations true of the world? you test a model predict future behaviour, check if it occurs yes: more con鍖dence no: adapt or fully reject model Friday, May 4, 12
- 11. A word on statistics some models are stochastic, their behaviour is stochastic but all data are subject to chance variation; you use statistics for the latter, to quantify uncertainty in your decision to accept the model or reject it Friday, May 4, 12
- 12. What use are models? Are the generalizations useful in the world? you explain the world by using model generalizations on phenomena you control the world by using the model to predict phenomena Friday, May 4, 12
- 13. Design research, focused on artefact design for control Friday, May 4, 12
- 14. artefacts are designed and developed to help control the empirical world there always are desired phenomena, the artefact causes them to occur there thus is a targeted state of the world and an obtained state of the world Friday, May 4, 12
- 15. St Si So I Friday, May 4, 12
- 16. building an aeroplane to 鍖y setting up an organization (bank) to lend money to investors building a learning network to facilitate competence development, creativity and knowledge sharing of non-formal learners Friday, May 4, 12
- 17. Artefactual models As the artefact is to perform a function, you now build a model that describes the artefacts behaviour, using bits and pieces of relevant theoretical models Such a model I call an artefactual model, to distinguish it from theoretical models Friday, May 4, 12
- 18. Test to the extent it incorporates theoretical models, con鍖dence carries over from them to the extent it rests on untested assumptions (structural and parametric) you test it experts, independent tests you thus contribute to theor. model dev.! Friday, May 4, 12
- 19. Simulate Use the artefuactual model to explore the artefacts behaviour through simulations Empirical tests are costly, dangerous, unethical, etc. Simulations are pseudo-performance tests of the artefact They may lead to design improvements Friday, May 4, 12
- 20. Empirical test Carry out empirical tests of artefact performance effectiveness - gap between actual and desired behaviour ef鍖ciency - costs of obtaining desired performance level increase sustainability - costs of maintenance Friday, May 4, 12
- 21. How Friday, May 4, 12
- 22. Model ingredients 1. identify the system and its boundaries: draw a causal network 2. identify variables and constants 3. identify state variables (laws of succession, variables that describe state transitions) and and input variables (variables that drive change) Friday, May 4, 12
- 23. 1. choose output variables, what changes you want to measure (could be a state variable) 2. choose a suitable modelling language analytic, using math. equations, often differential equations numerical, using computers, dedicated language, e.g. Netlogo, Stella, Brahms, ... Friday, May 4, 12