Hypotheses and Variables

Hypothesis

An educated guess or a presumption that is based on a scholar’s review of the research literature

Null Hypothesis

A hypothesis that predicts no relationship or difference

Alternative Hypothesis

A hypothesis that predicts that there will be a relationship or difference

Null Hypothesis Significance Testing (NHST)

Accept or reject hypothesis by evaluating the probability that no relationship exists, given the data (observations), we can say how confident we are that the relationship found is not by chance

Variable

The properties or characteristics of people or things that vary in quality or magnitude from person to person or object to object (different values)

Independent variable (x)

a variable whose changes in values result in changes in another (dependent) variable

Dependent variable (y)

a variable whose values change as a result of changes in another (independent) variable

Third Variable

a variable that could be the cause of movement in both the IV and DV

Type I Error

The researcher rejects the null when s/he should not have rejected the null

Type II Error

The researcher does not reject the null when s/he should have rejected the null

Significance Level

a criterion for accepting or rejecting a null hypothesis

P

value (p </= 0.05)