Testing, testing...

The Basics

Expressing Your Stats

Probability, Chance, and Error

Terms

100

A common test for an association between two variables of ratio data.

What is a Pearson's r? (or Pearson's product-moment correlation)

100

Statistics are to samples as _______ are to populations.

What are parameters?

100

Number of decimal places for reporting r-values and F-ratios.

What is two?

100

Each person in the population has an equal chance to be included.

What is a random sample?

100

The name for the statement that there will be no difference, effect, or change between the groups measured.

What is a null hypothesis?

200

The test you would use to determine whether a significant difference exists between men and women on mean scores.

What is an independent-samples (or independent-measures) t test?

200

Parametric and Nonparametric

What are two types of inferential statistics?

200

The type of score which expresses the difference of a score from the mean in units of standard deviation.

What is a z-score?

200

The name for the criterion for significance set by the researcher.

What is the alpha level?

200

The set of all individuals of interest in a particular study.

What is the population?

300

The test you would use to determine whether there are differences in the mean scores when there are three levels of the independent variable.

What is an ANOVA?

300

Type of relationship exemplified by correlation between final examination grade and course grade.

What is a positive correlation?

300

Cohen's d is an expression of this important measure of magnitude of changes resulting from a treatment.

What is the effect size?

300

The type of error committed when a researcher rejects the null hypothesis when it is, in fact, true.

What is a Type I error?

300

The presence of a true or meaningful zero differentiates these two scales of measurement.

What are interval and ratio?

400

The test you would use to determine whether pre and posttest scores differed for a group of PSY302W students.

What is an dependent-measures (or repeated-measures, or correlated-measures) t test?

400

The category of statistical tests used when a distribution is nonnormal.

What is nonparametric?

400

A graph of ordinal or ratio data in which adjacent, touching, vertical bars express the frequency for that category.

What is a histogram?

400

The p value when there is no more than a one in twenty chance of significant results being due to chance (sampling error).

What is .05?

400

For a sample of n scores, n-1.

What are degrees of freedom?

500

The test you would use to determine whether there are differences in frequencies between three categories of nominal data.

What is a chi-square (better - chi-square goodness of fit).

500

In a normal distribution, 68.26 of the cases.

What is fall within one standard deviation of the mean?

500

The category of effect size associated with an r value of .78

What is a large effect?

500

The average distance between the sample mean and the population mean.

What is the standard error?

500

Based on sample size and other factors, this is the statistic's ability to correctly reject the null hypothesis.

What is statistical power?