PS2080 - Making theoretical Progress

Deductive Reasoning

- top down

- more narrow

- concerned with hypothesis testing

- theory - hypothesis - observation - confirmation

Inductive Reasoning

- bottom up

- open-ended

- more exploratory

- observation - pattern - tentative hypothesis - theory

- induction Problem

- what about unobservable facts?

- our observations may be wrong

- our observations are not objective

Popper (1902 - 1994)

- austrian born scholar

- member of the vienna circle

- professor at the london school of economics

- popper's initial interest was psychology

- falsification instead of verification

Popper

- science constantly questions its explanations

- falsification - disproving a theory or hypothesis

- a scientific statement is one that could possibly be proven wrong

- falsifiability - criterion for demarcating sceince form non-science

- hypothetico - deductive method: observation - interpretation - hypothesis - test - observation etc

hypothesis should be directed at a possible falsification

Degrees of falsification: the more falsifiable a theory, the higher its scientific status

the more specific a statement, teh more proe to falsification, the higher the scientific status

e.g. wine sours because of organisms v wine sours because of bacteria coming from the air

- Scope: a good theory makes wide-ranging claims about the world

- Precision: the more precise a theory the more falsifiable it is

- Parsimony: among competing theories, the one that makes the fewest assumptions should be favoured

- Increasing falsifiability: the more falsifiable a theory the better. Theories should become more and more falsifiable: more content + more informative - a replacement theory should be more falsifiable than that which is replaced

- Fruitfulness: has the theory led to new empirical discoveries? does the theory lead to scientific progress? falsifying theories and offering more precise and falsifiable replacements leads to new discoveries

ad hoc modification = changes to a theory that makes the theory less falsifiable

What are allowable and unallowable modifications?

Thomas Kuhn 1922 - 1996

- american physicist

- the structure of scientific revolutions

- science is a social activity

- scientifc paradigm - set of common views of what the discipline is about and how problems should be investigated

Kuhn's theory of scientific progress:

pre-science - normal science - crisis - revolution - new normal science - new crisis etc

A paradigm determines:

what is to be observed and scrutinized

- what kinds of questions should be asked

- how the questions are to be structured

- how the results of scientific investigations should be interpreted

- how an experiment is to be conducted

- what equipment will be used

Pre-science: unorganised facts, observations and models to explain small scale phenomena

Normal science: researchers share paradigms. attempts made to falsify the theory. modification can be made

Revolution: confidence in paradigm decreases, crisis, scientific revolution and paradigm shift

- paradigms are ever changing

- revolution = progress?

- knowledge = relative and time dependent

- scientists engage in 'puzzle solving'

• Kuhn - normal science = important, Popper = noraml science does exist but does not = good science
• Kuhn - scientists should criticise occasionally, Popper - scientific approach = criticial attitude
• Kuhn - hypercriticial scientists don't get any work done + conformity and focused puzzle-solving are essential, Popper - criticism and non-conformity are essential

Objective component, grounded in reality,  constant coupling of ideas to observations by using verification and falsification in a guarantee that the ideas will not be completely in contradiction with the reality as it can be observed

Science proceeds by trial and error and happens within a paradigm - people should always be criticial of scientific claims

rule of thumb: look at converging evidence

long series of different falsifcation attempts