So……What is science?Deduction?Induction?Ecology and Science ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ “…the aim of science [is] to find satisfactory explanationsof whatever strikes us as being in need of explanation” (Popper 1972:191)“Prediction and explanationare the twin pillars upon which the scientific enterprise rests.” (Casti and Karlqvist 1991:vii)GOAL OF SCIENCE: ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ PHILOSOPHIES OF SCIENCE“because all theories remain] guesses, conjectures, hypotheses… we are therefore at best always faced with the question of preferring, tentatively, some guesses to others…” (Popper 1972:13)1) Begin with a problem based on observations that generate new questions or contradict established theory2) Develop conceptual hypothesis/model3) Formulate specific hypotheses/models (several of them) that make testable predictions4) Devise critical test and repeatedly test hypotheses looking for falsification (evidence contrary to model predictions)5) Retain unfalsified hypothesis. If >1 unfalsified hypothesis, retain the one with greatest degree of corroborationKarl Popper**Note: This basically ends Popper‟s method of science. However, he also briefly stated that if you could falsify all but one of the total possible competing theories you would have retained the TRUTH. This is the basis for hypothetico-deductive method and Platt's (1964) "strong inference" ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________PHILOSOPHIES OF SCIENCE"All theories...are born refuted and die refuted. But are they equally good?" (Lakatos 1978)·Same as Popper to start:1) Begin with a problem based on observations that generate new questions or contradict established theory2) Develop conceptual hypothesis/model3) Formulate specific hypotheses/models (several of them) that make testable predictionsTHEN: Keep best available hypothesesDo not have to retain only unfalsified hypotheses because of the philosophy that hypotheses may never be truly falsifiedScience may keep a hypothesis that is wrong if there is not a better one available .Basis for Information Theoretic Model Selection ApproachImreLakatos ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Statistical Approaches to ScienceHypothetico-deductive:Test a single hypothesis using frequentistmethodsFollows Popper in that a statistical null hypothesis of „no effect‟ is crafted and tested.Biological significance vs statistical significancePlatt‟s Strong Inference:As above but testing a series of multiple alternative hypotheses to eliminate as many as possible ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Statistical Approaches to ScienceInformation Theoretic Approach:Competition between multiple hypotheses (models) and the data.Meaningful hypotheses (models) determined a priori.Data collected and models runUses an objective criterion to rank best model(s) -AICIdea of parsimonyModel averaging ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________
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