Research Statistics Review

Descriptive statistics involves

• generalizing from a sample

• testing hypotheses

• measures of central tendency

• inferences

Inferential statistics involves

• description of a sample characteristics

• testing hypotheses

• central tendency measures

• percentage distributions

What is generalization as applied to research studies?

• Extension findings to a larger population

• Internal validity of a measurement

• inter-rater reliablity of a measurement

• summary of descriptive statistics

What is external validity?

• generalization to a larger population

• relationships reflect reality rather than extraneous variables

• limitations of a study

• validity of extraneous variables

Which is true of the normal distribution?

• Approximately 34% falls within 1 standard deviation above and below the curve

• The percentages in each section of the curve cannot be known

• Approximately 68% falls within 1 standard deviation above and below the curve

• Few variables follow the characteristics of the normal distribution

What is a Type I error in research?

• failing to reject the null when the null is false

• failing to reject the null when the null is true

• rejecting the alternative when the alternative is true

• rejecting the null when the null is true

What is a Type II error?

• rejecting the null when the null is true

• failing to reject the null when the null is false

• rejecting the null when the null is false

• failing to reject the null when the null is true

What is power in a statistical test?

• ability to detect a difference when a difference exists

• risk of a type I error

• risk of rejecting a null that is true

• failure to reject the null when the null is true

Which of the following techniques increases the power of a statistical test?

• increasing sample size

• decreasing the alpha level

• decreasing the effect size

• eliminating data

Which of the following statistical tests measures relationships between variables

• correlation

• t test

• descriptive statistics

• ANOVA