Chapter 10- Induction

Inductive reasoning - Reasoning whose premises support a probable conclusion without guaranteeing it, even when the premises are true.

Deductive reasoning - Reasoning in which a valid argument guarantees a true conclusion if all its premises are true.

Inductive strength - The degree of support that an inductive argument’s evidence provides for its conclusion.

Inductive generalization - Using observations of a sample to draw a probable conclusion about a whole population.

Population - The entire group an investigation aims to draw conclusions about.

Sample - The portion of a population actually observed or examined.

Sampling - Examining part of a population to draw conclusions about the whole population.

Representative sample - A sample that reflects the relevant characteristics of its population.

Biased sample - A sample that misrepresents its population in ways that could affect the conclusion.

Sample size - The number of cases or members examined in a sample.

Homogeneous population - A population whose members are similar in relevant characteristics.

Assessing an inductive generalization - Check whether the sample is representative and large enough.

Statistical syllogism - Using a population statistic to estimate the probability that a characteristic applies to an individual member.

Inductive generalization versus statistical syllogism - Generalization moves from sample to population; statistical syllogism moves from population statistics to an individual.

Assessing a statistical syllogism - Check whether additional relevant information about the individual has been overlooked.

Criterion of adequacy - The requirement that premises provide enough support for the conclusion.

Criterion of relevance - The requirement that premises bear on whether the conclusion is true.

Hypothesis - A statement or principle that would explain an event or situation if true.

Observation statement - An empirical prediction stating what should be observed under specified conditions.

Induction by confirmation - Supporting a hypothesis by observing that predictions derived from it are true.

Form of induction by confirmation - If h, then o. o is observed. Therefore, h is probably true.

Confirming instance - An observation that matches a prediction derived from a hypothesis.

Disconfirming instance - An observation showing that a prediction required by a hypothesis is false.

Confirmation versus disconfirmation - Confirmation adds probable support; a genuine disconfirmation of a required prediction can refute the hypothesis.

Assessing induction by confirmation - Check the number and variety of confirming instances and look for disconfirming instances.

Negative result - A test result that fails to match a hypothesis’s prediction.

Hypothesis revision - Changing a hypothesis to address evidence; the revised version is technically a different hypothesis.

Affirming the consequent - The invalid deductive form: If h, then o. o. Therefore, h.

Denying the consequent or modus tollens - The valid deductive form: If h, then o. Not-o. Therefore, not-h.

Analogical reasoning - Using relevant similarities between cases to support a probable conclusion about a further similarity.

Analogy - A comparison between objects, situations, or relationships.

Analogue case - The familiar case used as evidence in an analogical argument.

Subject case - The case about which an analogical argument draws its conclusion.

Target feature - The particular characteristic or relationship inferred about the subject case.

Property - A characteristic of a thing considered on its own, such as colour or size.

Relation - A connection between two or more things, including parts of one object.

Analogical argument by properties - Inferring that cases sharing some properties probably share another property.

Form of analogy by properties - x has A, B, and C. y has A and B. Therefore, y probably has C.

Analogical argument by relations - Inferring that a relationship found in one case probably also occurs in a comparable case.

Relevant similarity - A shared feature that matters to the target feature or conclusion.

Relevant dissimilarity - A difference that matters to the target feature or conclusion.

Strong analogy - A comparison whose relevant similarities provide substantial support despite its relevant differences.

Weak analogy - A comparison whose relevant differences or lack of relevant similarities leave the conclusion poorly supported.

Assessing an analogical argument - Identify the target feature and weigh relevant similarities against relevant differences.

Three uses of analogy - Clarifying an idea, suggesting a hypothesis, and providing probable support for a conclusion.