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Science as a way of knowing the world John S. Wilkins, Philosophy, University of Queensland

Science as a way of knowing

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Page 1: Science as a way of knowing

Science as a way of knowing the world

John S. Wilkins, Philosophy, University of Queensland

Page 2: Science as a way of knowing

The scientific method

• Who can summarise the scientific method?

• Who is right? Answer: Probably everyone

• There is no single algorithm for the scientific method. It’s not a recipe for success

• But there are several shared features of all acts of science

• There are also several shared mistakes scientists make

• Today I want to discuss some of these.

Page 3: Science as a way of knowing

The scientific method is a dance

• Just as there’s not much that all dances share apart from a dance floor, there’s not much that all sciences share either

• But there are some common features:

• Theories

• Models

• Data

• Classifications

Page 4: Science as a way of knowing

The scientific method is a dance

• Just as there’s not much that all dances share apart from a dance floor, there’s not much that all sciences share either

• But there are some common features:

• Theories

• Models

• Data

• Classifications

Page 5: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 6: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 7: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 8: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 9: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 10: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 11: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 12: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 13: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 14: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 15: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 16: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 17: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 18: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 19: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 20: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 21: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 22: Science as a way of knowing

Experiment

Passive Observation

Theory Classification

Conceptual

Empirical

The dance floor

Page 23: Science as a way of knowing

Making models

• Theories are composed of models, together with linking (“bridging”) rules that relate them, and “interpretations”, or ways to assign empirical data to the variables of the theory

• In an example, consider the theory of global warming: There are many models (of heat sink and dissipation of oceans, of carbon dioxide absorption, etc.), which inter-relate, but all have different equations governing the model, and different sets of variables

• A model is basically a set of inter-related equations. They are based on prior knowledge of how things work, together with observations of the conditions of the thing[s] under study

• How do we know what prior knowledge applies in this case?

Page 24: Science as a way of knowing

Theories and models

• There are several kinds of theory and several kinds of model. Some theories apply in every case (e.g., laws of physics). Some apply only in limited cases (a theory of the origins of the Civil War in England).

• What kinds of theory and models apply in ecology and conservation?

• Global theories (island biogeography?)

• Restricted theories (trophic relations in, say, tropical savannah biomes)

• Local models (a model of what will happen in a certain system)

Page 25: Science as a way of knowing

What worries me about conservation biology

• I have seen a lot of discussion about the right methods to develop conservation plans, from Bayesian models to decision theoretic accounts based on expected payoffs and values

• I have heard of a lot of conservation plans that deal with individual based models or “agent” modelling (the idea is to model the ecosystem or area without a general rule, but use dynamics of individual organisms to predict how things will develop in complex cases) – what seems to be lacking with these is follow-up.

• How successful were they?

• What general problems were encountered?

• How can the models be improved?

• Without knowledge of rules of success, this is merely a matter of being seen to do something

Page 26: Science as a way of knowing

Mistakes that scientists make with theories and models

• Suppose we have a theory (of being called in the bath); we have to test it and revise it

• We need to ensure that the theory is not mistaken for the thing (this is called reification or “thingifying”) – the map is not the territory

• Often arguments between scientists overlook this distinction: theories are in heads. The world is not (except for the bits of the world that are heads)

• So the objects of the theory can be wrongly ascribed (for example, genes)

Page 27: Science as a way of knowing

Mistakes that scientists make with theories and models

• Models are simplifications – often over simplifications

• So if a model predicts X, it need not be that X will follow

• If a model is not robust, slight differences in the conditions will cause great differences in outcomes

• If there are things happening the model doesn’t cover, predictions can be wildly wrong

• If several models are not independent (i.e., they share assumptions, equations, methods, data sets) then they may not be additive in their weight

• Theories can force models that back up those same theories; be careful of circularity

Page 28: Science as a way of knowing

Summary

• Science is like an open dance floor - fill in the empty spaces! [In more formal language - the aspects of the scientific process that are lacking in your field need to be done]

• Theories are not useful in themselves unless they are tested and refined

• And neither are models, methods, protocols, procedures or practices

• Don’t confuse what’s in the theory (in yours and others’ heads) with what’s in the world

• And finally: all of this is subject to practical need

Page 29: Science as a way of knowing

Resources

• Figures and argument at Backreaction, a blog by two physicists

• Science as a Way of Knowing, by John Moore

• Ecological Orbits: How Planets Move and Populations Grow, by Mark Colyvan and Lev Ginsburg

• Wikipedia articles: Epistemology, Science, Scientific Method, Models of Scientific Enquiry

• Stanford Encyclopedia of Philosophy articles: Epistemology, Scientific Method, Models in science