Methodology I HD-method ( S7&8, App. 7A/B, 8A)

Methodology IHD-method (S7&8, App. 7A/B, 8A) • for testing and further evaluation of theories • derive and test (general and individual) test implications (in observation terms) • examples • Einstein-Eddington: GRT light bending • Newell&Simon: physical symbol system hypothesis • a physical symbol system has the necessary and sufficient means for general intelligent action • falsification or confirmation (no verification!)

Dogmatic HD-strategies: challenge (App. 7B) • auxiliary hypotheses (many types, see DN-model) • validity of logico-mathematicalargumentation • observation presuppositions • initial test conditions • decision criterion (statistical/approximative) • inductive jump (to general success)

Separate HD-evaluation • HD-method applied to theory X • derive and test general test implications • per I: ito (in terms of)individual test implications, • either falsification: by individual counter example of I, and hence of X • or acceptance of I: general success of X • NB: success: prediction or explanation, minimal. derivable

Negative: problems Asymmetric model: individual counterexamples Symmetric models: general counter-examples indicvidual counterexamples Positive: successes general successes general successes individual successes Evaluation report of X at t

Comparative HD-evaluation • Def: Y is at t more successful than X • no extra counter-examples • previous successes are retained • more successes and/or fewer counter-examples • Asymmetric (S8.1), or symmetric (S.8.2) • then with (qualitative or quantitative) comparative matrix • CSH: Comparative Success Hypothesis: • Y remains at least as successful as X • interesting hypothesis, • even if Y is already falsified!

Rule of Success (Instrumentalist):IRS • IRS: If CSH has been “sufficiently” tested, choose, for the time being, the more successful theory • Application of IRS: empirical progress • CLAIM: IRS, and hence the HD-method, are functional for truth approximation

General Methodological Principles • 1) Falsifiability (= confirmability/testability) • 2) Evaluation (=> evaluation report) • specifically: aim at likely falsification (= potential strong confirmation!) • 3) Improvement Principle (IP) (=> empirical progress) • not:elimination-principle (EP) (Popper?) • e.g. by idealization and concretization • 4) For remaining choices: simplicity, and other aesthetic criteria

Dogmatic behaviorKuhn/Lakatos App. 8A • Improvement principle (IP) • Programmatic improvement principle (PIP) • aim at a better theory with the same hard core • if necessary, adapt the hard core • if no other option, look for another program • (P)IP functional for empirical progress and truth approxination • Types of dogmatic behavior: • scientific: if with PIP • pseudoscientific: if without PIP

Hiërarchie van epistemologische posities Q0: onafhankelijke natuurwerkelijkheid? Nee  ontologisch idealisme  Ja: ontologisch realisme Q1: ware claims mogelijk? Nee  epistemologisch relativisme - ervarings-scepticisme  Ja: epistemologisch realisme - inductief scepticisme Q2: voorbij waarneembaar? Nee  observational realisme - instrumentalisme  Ja: wetenschappelijk realisme - constructief empiricisme Q3: voorbij referentie? Nee  referentieel realisme  entiteiten realisme  Ja: theorie-realisme Q4: ideale conceptualisering? Nee  constructief realisme  Ja: essentialistisch realisme

Vier perspectieven voor theorie-realisme

Soorten actuele en nomische waarheidsbenadering • PM: het beste afleidingsinstrument: instrumentalist • observationeel: constructive empiricist • referentieel: referentieel realist • theoretisch: constructief realist • essentialistisch: essentialistisch realist PM: “de waarheid”: de sterkste ware theorie over een gegeven domein in een gegeven vocabulair

Conclusies ICRvooruitblik: How to approach the truth? • goede redenen voor overstap:instrumentalist 1 constructief empiricist 2 referentieel realist 3 constructief realist, maar niet voor 4 essentialist • 1,2  3 tbv lange termijn dynamiek: theorieën als waar accepteren  levert nieuwe observatietermen • instrumentalistische methode efficiënter voor waarheids-benadering dan falsificationistische methode • hiërarchie van heuristische posities, geen dogma • everything goes sometimes • reculer pour mieux sauter

A probabilistic perspective on the hypothetical method Theo A.F. Kuipers, Groningen, www.philos.rug.nl/personae/kuipers • concept explication by I&C I.e. idealization and concretization (to appear A) • tested by the approximative reduction principle: AR-test, i.e. extreme special case

From d- to p-consequences • Idealization: H E: E deductive (d-)consequence of H • Concretization: p(E/H) > p(E): E probabilistic (p-)consequence of H 1 > p(E/H) > p(E): E pp(proper p)-consequence of H • AR-test: let HE, then p(E/H)=1 > p(E) hence, assuming p(E)<1, a d-consequence is a p-consequence • To be studied: PCn(A) =def {B/p(B/A)>p(B)}

Comparisons Not: probable consequence/validity, e.g. • J.L.Cohen: The provable and the probable • mainly about Baconian vs Pascalian probabilities • F. Jackson: assertability of a conditional (AB) iff p(B/A) high Perhaps: probabilistic conditional/validity, but not so e.g. • R. Bradley and N. Schwartz: “B follows probably from A” = • iff most models of A are models of B • E. Adams: “probability conditional” = p(B/A), and “p-validity” = uncertainty conclusion  sum uncertainty premises To be checked: D. Lewis, R.C. Jeffrey, F.P. Ramsey, R. Stalnaker

From the HD- to the HP-method of testing Definition E is a d-/p-test implication of H iff E is an ‘observational’ d-/p-consequence of H • Idealization: Hypothetico-Deductive (HD-)Method aims at d-confirmation or falsification of d-test implications • Concretization: Hypothetico-Probabilistic (HP-)Method aims at p-confirmation or p-disconfirmation of p-test implications

From d- to p-confirmation: Conclusions Analysis ICR Part I (SiS Ch. 7.1.2) • There is a coherent landscape of confirmation notions, allowing different languages of (degrees of) confirmation • Idealization: Deductive confirmation • Concretization: Probabilistic confirmation • basic definition: p(E/H)>p(E) • instead of standard: p(H/E)>p(H) • ‘p’ may be Popperian: no inductive means Carnapian: only inductive likelihoods Bayesian: only inductive priors Hintikkian: both • which one, no fact of the matter

Challenge • A coherent I&C explication of deductive and probabilistic methods of testing and of separate and comparative evaluation, taking counterexamples into account • testing sep. eval. comp. eval. deductive ICR ICR ICR    probabilistic ICR/SiS to be done to be done

HD- and HP-testing and -evaluation

D-/P-Evaluation Matrix (Bx: deductive boxes, ICR/SiS)

DN-/PN-predictions and -explanations: “H predicts/explains E, assuming C (=A&B&C)” • DN-idealization H&C E • PN-concretization p(E/H&C) > p(E/C) • AR-test: OK • assuming C, E2 more risky prediction of H than E1, iff p(E2/C) < p(E1/C) andp(E2/H&C)  p(E1/H&C) • assuming C, H2 explains E better than H1, iff p(E/H2&C) > p(E/H1&C)

Comparative Evaluation and Truth Approximation • ICR-story in terms of positive and negative HD-results: • Definition “more successfulness” • Comparative Success Hypothesis • Instrumentalist Rule of Success (IRS) • Inference to the Best Theory (IBT, to appear B) • Inductive Jump to the Best Theory (to appear B) • Extendable to HP-results!?

Conclusion • There is a HP-method as a straightforward concretization of the HD-method: AR-tests: • all transitions from p- to d-notions: p (E/H)=1/0 • from separate evaluation to testing: not yet falsified • from comparative to separate evaluation: one tautology • Depending on p: Popperian, Carnapian, Bayesian, Hintikkian • Enabling: testing; separate and comparative evaluation; explanation and prediction • To be further studied • similar perspectives on truth approximation • PCn(A) =def {B/p(B/A)>p(B)}

References Kuipers, T. (ICR/2000), From Instrumentalism to Constructive Realism, Synthese Library 287, Kluwer AP, Dordrecht, Kuipers, T. (SiS/2001), Structures in Science, Synthese Library 301, Kluwer AP, Dordrecht, To appear A: ” Empirical and conceptual idealization and concretization. The case of truth approximation", to appear in Liber Amicorum for Leszek Nowak, homepage To appear B: ” Inference to the best theory, rather than inference to the best explanation”, to appear in Proceedings ESF-workshop Induction and Deduction in the Sciences, Vienna, 2002, homepage.

Methodology I HD-method ( S7&8, App. 7A/B, 8A)