Chapter 2 Flashcards
Scientific inference
Inference
An act or a process of reaching a conclusion from a set of premises, which can express, for instance, known facts or evidence
Premise
A statement in an argument that justifies a conclusion
Conclusion
A statement that follows logically from premises
Direct inference
Inductive inference from a proportion in a sample to a population
Generalization
Inductive inference from a sample to a general conclusion
Projection
Inductive inference from past samples to future samples. Distinguish from prediction; projection is one way to make predictions
Inductive inference
In an inductive inference, the premises support the conclusion but does not guarantee its truth
Deductive inference
In a valid deductive inference, true premises necessitate the truth of the conclusion
Conditional claim
A claim involving the logical operator “if”, for instance of the form “If A then B”
Modus ponens
A deductive inference of the form: (i) If A then B, (ii) A, therefore (iii) B
Modus tollens
A deductive inference of the form: (i) If A then B, (ii) not B, therefore (iii) not A
Ampliative
Inferences that go beyond what is stated in the premises - in particular, inductive inferences are ampliative
Explicative
Inferences that do not go beyond what is stated (implicitly) in the premises - in particular, deductive inferences are explicative
Truth preservation
The conclusion must be true if the premises are true, see deductive inference
Fallibility
The conclusion can be false even if premises are true
Infinite regress
A never ending chain of propositions being justified by other propositions which in turn are justified by other propositions and so on
Foundationalism
Propositions are justified by being inferred from foundational premises which do not need additional justification, for instance necessarily true premises
Coherentism
Propositions are justified by being compatible with a coherent set of propositions, where each proposition in the set is compatible with every other proposition in the set
Falsification
Rejecting a hypothesis as a result of an empirical test
Confirmation
Increasing the confidence in a hypothesis as a result of an empirical test
Hypothesis (plural: hypotheses)
A proposition that can be true or false but is not necessarily true or false, and that preferably either has some generality or is about something not directly observable
Tautology
A proposition which is necessarily true
Direct observation
Observations of object and properties that are accessible through the use of human senses
Operationalization
A way to measure something which cannot be directly observed or that cannot be observed directly with sufficient precision, by connecting this feature with something causally connected to something that can be observed
Asymmetry between falsification and confirmation
No amount of confirming observations can deductively confirm the hypothesis, but one falsifying observation can deductively falsify the hypothesis
Falsificationism
The view that science should proceed only through valid falsification, and never use confirmation
Falsifiable
A hypothesis is falsifiable if it is possible to show that it is false, even if it has not yet been shown to be false
Demarcation of science
Distinguishing science from non-science by providing criteria for counting something as science
Corroboration
A hypothesis is corroborated if it has withstood multiple falsification attempts
Auxiliary hypothesis
A hypothesis used to test another hypothesis, but which one does not intend to test, for instance background assumptions necessary to infer the empirical conclusion
Conjunction
Two propositions joined by the logical operator AND. The conjunction is true if an only if both propositions are true
Duhem-Quine thesis
No hypothesis can be tested without the use of auxiliary hypotheses
Ad hoc
The modification of a claim is ad hoc if (i) the claim has previously been falsified, (ii) the modification saves the claim from this falsification and (iii) it makes the claim less falsifiable - i.e. it does not allow deriving any new testable consequences
Frequentism
Probabilities are frequencies of repeatable observable events
Under-determination
An inference is underdetermined if multiple conclusions would be supported by the premises
Severe test
A hypothesis test is a severe test if the probability to observe a consequence would be low if the hypothesis were false
Base-rate fallacy
Initial confidence in an hypothesis is not taken into account when performing a statistical hypothesis test
