Inductive Flashcards
No inductive argument is a valid deductive argument.
Deductive arguments try to determine their conclusion with certainty.
The criteria for evaluating inductive arguments are criteria that tend to show that an inductive argument is strong or weak.
Principle of the Uniformity of Nature
That the laws of nature that have held in the past will continue to hold in the future; assumed in all inductive arguments.
Strength of inductive arguments’ conclusion
Strength of a conclusion is determined by the amount of evidence needed to show that the conclusion is false.
A ‘strong conclusion’ takes little or merely one example to prove its conclusion false.
A ‘weak conclusion’ takes a lot of evidence to show it is false. They tend to be more general; ie harder to prove to be wrong.
Inductive generalizations are based on a sample.
Sample: a limited collection of objects of the kind under investigation.
Diversity of the sample makes for better information, and if the number used in the sample is increased the probability of the truth of the conclusion increases.
Inductive counterexample
A case that is sufficient to show that the conclusion of an inductive argument is false.
Criteria for evaluating inductive arguments by enumeration
- As the number of objects taken into accounts increases, the generalization is strengthened.
- The more diverse the sample is, the better the basis for the generalization is.
- The stronger the conclusion is, the weaker the argument is.
Analogy
A likeness drawn between two or more entities in one or more respects.
Analogies are used to enhance description and to aid in explanation, such as metaphor and simile.
Analogical argument
A type of inductive argument in which it is concluded that two entities are alike in some respect, on the ground that they are alike in some other respect(s).
Every analogical inference proceeds from the similarity of two or more things in one or more respects to the similarity of those things in some further respect.
The 4 basic elements of an analogy
- Ground for the analogy
- Objective extension of the analogy
- Basis of the analogy
- Problematic extension of an analogy
1.Ground for the analogy
The entities having all the properties under consideration
- Objective extension of the analogy
The entity compared to the ground of the analogy and which is known to have a number of properties in common with the entities in the ground.
- Basis of an analogy
Those properties known to be common to the ground and the objective extension of the analogy.
- Problematic extension of an analogy
That property common to the objects of the ground not known to be a property of the object extension.
The 6 criteria for appraising analogical arguments
- Number of entities
- Number of similar respects
- Variety of instances in the premises
- Relevance
- Disanalogies
- Claim that the conclusion makes
- Number of entities
In general, the larger the number of entities compared (the larger the ground for the analogy), the stronger the argument is.
- Number of similar respects
The larger the number of respects in which the entity in the conclusion is similar to the entities in the premises (the more properties that are included in the basis), the more probable it is that the conclusion is true.
- Variety of the instances in the premises
When a significant number of things are similar in a significant number of respects (when the ground and the basis are strong), differences among objects in the ground can strengthen the evidence for the conclusion of the analogy.
- Relevance
Respects add to the force of the argument when they are relevant, and a single highly relevant factor contributes more to the argument than a host of irrelevant similarities.
- Disanalogies
Disanalogy: a point of difference, a relevant respect in which objects in the ground for the analogy differ from those in the objective extension.
Disanalogies undermine an analogical argument; dissimilarities among the premises reinforcing period. Disanalogies tend to show that there are relevant respects in which the case in the conclusion differs from those in the premises; dissimilarities among the premises tend to show that what might have been thought causally relevant to the attribute of interest is not relevant at all.
- Claim that the conclusion makes
Generally, the weaker the conclusion the less burden is placed upon the premises and the stronger the argument; the stronger the conclusion the greater is the burden on the premises and the weaker the argument.
H1: a hypothesis must be testable
Tests can give evidence to confirm a hypothesis
H2: if predictions based upon a hypothesis are true, this tends to show that the hypothesis is true
If there is no way to test a hypothesis, there is no direct way to falsify it. Thus, if the hypothesis has testability it can be confirmed or falsified and is practical and not just theoretical.
H3: a hypothesis is more probably true if it has a broader explanatory scope, that is, if it explains more phenomena than alternative hypotheses.
Consilience: the tendency of several forms of inductive evidence to point to the same conclusion.
H3 is important when a hypothesis will explain an anomaly, a fact that cannot be explained in the basis of an accepted hypothesis or theory.
H4: Principle of Parsimony (Ockham’s Razor)
If either of two hypotheses will explain a phenomenon and one involves fewer theoretical assumptions, the hypothesis that involves fewer assumptions is more probably true.
The smaller the number of theoretical assumptions, the easier it is to falsify the hypothesis (theory) as well as to confirm it.
