Falsifiability - Methods in the Behavioral Sciences - Lecture Slides, Slides of Behavioural Science

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alsifiability: How to Foil Little Green Men in the Head

Logic of Experimentation †

Two forms of logic: „

Deduction – moving from general principles tospecific conclusions. „

Induction – moving from specific observations to

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general principles.

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Induction is used during naturalistic andexploratory research.

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Deduction is used during experiments.

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Logical Fallacies †

Affirming the consequent „

If p then q „

Observe q „

Conclude p

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Denying the antecedent „

If p then qIf

p then q

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Observe not-p „

Conclude not-q „

Conclude not q

Falsifiability †

Seeking support for hypotheses commits thelogical fallacy of affirming the consequent.

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Instead, we must test hypotheses by seekingdisconfirmatory evidence.

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A testable theory is one that can be provenwrong – if it is wrong.wrong

if it is wrong.

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It must have the chance to fail. „

A theory cannot explain every outcome „

A theory cannot explain every outcome.

Two Hypotheses

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There will be no difference between treatmentand control groups (no treatment effect)and control groups (no treatment effect).

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Alternative hypothesis (H

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There will be a difference of a particular kind. „

Directionality – states how the treatment groupwill differ from the control groupwill differ from the control group.

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We test the null hypothesis and by rejecting it(disconfirming it) can accept the alternative.(disconfirming it) can accept the alternative.

The Neyman-Pearson Approach

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wo theories can be compared by predicting

incompatible outcomes:

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If

theory A is correct, hypothesis A will be confirmed and B will be disconfirmed. „

If theory B is correct hypothesis B will be „

If theory B is correct, hypothesis B will beconfirmed and A will be disconfirmed.

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The comparison is not with the control group

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The comparison is not with the control group( is there a treatment effect or not) but withthe predictions made by the two theories.

Working on the Fringes †

Interesting questions are those that: „

Exist at the fringes of knowledge. „

Can be tested using existing methods.

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Many questions are important but untestable.

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Some questions are interesting to the publicbut not to scientists because they have alreadybut not to scientists because they have alreadybeen answered: „

ESP and other paranormal claims astrology „

ESP and other paranormal claims, astrology.