Confirmation Flashcards
basic idea bayesianism
S beliefs that p with degree g between 0 & 1 equal to some probability function
Three pillars of Bayesianism
- quantitative conception of belief
- rational beliefs at any fixed given moment in time
- how beliefs at different moments in time ought to be related
credence g=0
total disbelief, contradictions (absurdum)
credence g=1
certain belief, tautology (veritas)
probability function of g
probability function is always in between absurdum & veritas, so between 0 & 1
incompatibility of p & q
Pr(p or q) = pr (p) + pr (q)
or Pr (p and q) = 0
bayesian explanation of propositional knowledge
p is true
s believes that p to a degree of 0.90 or larger
s has reached 0.90 by bayesian updating
confirmation
confirmation (e,h) iff e is empirical evidence & f (e,h) > 1
Infirmation
infirmation (e,h) iff e is empirical evidence & f (e,h) < 1
Irrelevance
irrelevant (e,h) iff e is empirical evidence and f (e,h) = 1
verification
maximal confirmation
Pr1(h) = Pr0 (h|e) = 1
Falsification
maximal infirmation
Pr1 (h) = Pr0 (h|e) = 0
mu (e,h)
quantify the degree of confirmation or disconfirmation that evidence e provides for a hypothesis. 10 for verification, -10 for falsification, irrelevance = 0.
Diachronic coherence
change of beliefs over time, quantified by belief-change factor f(e,h)
Hempel’s raven paradox
things that confirm should not confirm and things that do not confirm should confirm. Therefore, background knowledge is needed.
Example: seeing colored things that are not ravens confirms hypothesis that all ravens are black.