reality assumptions

Assumptions about what 

is true and factual that 

are sometimes stated 

and sometimes implied; 

these assumptions are 

often taken for granted.

inductive 

reasoning

the process of finding the truth 

by making observations through:

                    -statistical polls

                    -controlled experiments

                    -relevant examples

                    -analogies

deductive

reasoning

the process of inferring 

a conclusion by putting forth 

true premises

in a valid format

deductive

argument

an argument that follows

formal patterns of reasoning

and is aimed 

at establishing a certain conclusion

through presenting 

the premises 

in a valid form

valid

argument

an argument 

structured in a correct, deductive format;

if the premises are true

then the conclusion is true

sound

argument

when the form of an argument is valid 

and the contect is true

syllogism

a deductive argument

consisting of

two premises 

and 

a conclusion

major

premise

The statement in a syllogism 

that sets forth a general 

principle. (The major premise 

contains the term that is the 

predicate of the conclusion.) 

minor

premise

The statement in a syllogism 

that expresses an instance of 

the principle set out in the 

major premise. (The minor 

premise contains the term 

that is the subject of the 

conclusion.)

conclusion

In deductive 

reasoning, the inference 

drawn from the major and 

minor premises of a syllogism. 

categorical

statement

A statement in which 

members of one class are 

said to be included in another 

class. This statement may be 

used as the major premise of a 

syllogism.

conditional

syllogism

In deductive reasoning, a 

syllogism whose major premise 

asserts that if the condition 

cited in the first part of a 

statement is true, then the 

claim cited in the second part 

of the statement will follow. 

modus

ponens

A valid conditional/

hypothetical syllogism in 

which the antecedent is 

affirmed.

hypothetical

syllogism

 A 

syllogism in which the major 

premise presents a condition 

(“if A, then B”) or a possibility 

(“either A or B”) that is 

resolved in the minor premise 

so that a valid conclusion 

can follow. 

modus

tollens

A valid 

conditional/hypothetical

syllogism in which the 

consequent is denied.

chain

argument

a form of argument 

that builds

and depends upon

a series of conditions 

to be met

disjunctive

syllogism

A hypothetical syllogism in 

which two possibilities are 

given in the major premise 

and one is assumed to be 

necessarily true. In the minor 

premise, one of the possible 

alternatives is negated, and 

the remaining alternative 

is then affirmed in the 

conclusion.

"or"

argument

by

elimination

A valid syllogism that seeks 

to logically rule out various 

possibilities until only a single 

possibility remains. 

enthymeme

a syllogism with 

the key part or parts

implied rather than stated

grounds

Evidence offered 

to prove a claim. Grounds can 

consist of statistics, examples, 

research, physical evidence, 

logical reasoning, and expert 

opinion.

stereotyping

Classifying

people, places, or things 

solely on common traits while 

ignoring individual differences 

that make these comparisons 

invalid.

premise

of

contention

The premise of a deductive 

argument that is under 

dispute. This is also often 

called the contentious 

premise.

induction/

inductive reasoning

(often called 

inductive reasoning) 

The process of drawing 

generalizations from known 

facts or research to give 

strength and support to 

conclusions.

statistical evidence

Data collected by polling and 

research studies that can 

be used to make statistical 

generalizations

statistical

generalizations

Inferences drawn from 

statistical evidence that 

are used to give strength to 

inductive arguments. 

characteristic

of interest

The specific question that a 

researcher seeks to answer 

concerning a given population

target population

The group about which 

a researcher wishes to 

generalize.

sample

Members of the 

target population who are 

studied by a researcher. 

representative

A quality of 

a research sample in which 

the sample has the same 

significant characteristics in 

the same proportion as the 

target population. 

biased

A sample that 

does not reflect a random, 

representative population. 

A biased sample does not 

provide adequate evidence to 

support a conclusion.

randomness

A condition 

that allows every member of a 

target population to have an 

equal chance of being chosen 

as part of the sample.

causal generalizations

Generalizations based on 

causal factors; that is, they 

state that a particular factor 

is responsible for a specific 

effect. These generalizations 

are used to strengthen 

inductive arguments.

necessary condition

A condition (state of affairs, 

thing, process) that must be 

present if a particular effect 

is present. Equivalently, if the 

necessary condition is absent, 

then the effect cannot occur. 

sufficient

condition

A condition (state of 

affairs, thing, process) that 

automatically leads to the 

production of another event. 

If the condition is present, 

then the effect will definitely 

occur. The sufficient condition 

creates or causes the effect.

multiple causes

A combination of causes that 

are presumed to lead to a 

specific effect. 

immediate causes

A causal factor that 

immediately precedes the 

effect.

remote causes

Factors or 

conditions that led up to but 

did not immediately precede 

the effect. 

method of

agreement

A theory of causation 

postulating that the cause of 

an effect is found by noting 

that  X is the only factor always 

present when  Y (the problem 

or the good effect) occurs; 

therefore,  X causes  Y . 

method of difference

A theory of causation 

postulating that the cause of 

an effect is found by noting 

that the only difference 

between the event or effect 

(called Y) happening or not 

happening is whether one 

element—X—is present.