ALEC 695 Quiz 12: Statistics in Perspective

In a study in which all subjects receive both treatments, the appropriate descriptive statistic to use is:

• the Pearson correlation coefficient

• the mean

• the contingency coefficient

• Chi-Square

If eta and r are in substantial disagreement:

• eta should be used

• r should be used

• neither should be used

• an error in calculation has been made

A correlation coefficient of r = .05 can be interpreted as having both practical and statistical significance.

• True

• False

The first step in analyzing data in a comparison group study is to:

• calculate averages

• construct frequency polygons

• alculate measures of variability

• determine statistical significance

Which following term best describes curvilinear relationship?

• Alpha

• Beta

• Delta

• Eta

The most appropriate indicator of the importance of a relationship between two categorical variables is:

• the crossbreak table

• Chi-Square

• a comparison of actual and expected frequencies

• the contingency coefficient

In a study comparing class size to mathematics achievement, the unit of analysis is:

• the class

• the individual student

• the teacher

• none of the above

In a comparison group study using two randomly selected groups, effect size = .24, and p <. 01. This means the:

• difference in means is small and probably due to sampling error

• difference in means is small but probably is not due to sampling error

• difference in means is large enough to be important, but may well be due to sampling error

• difference in means is large and probably not due to sampling error

The importance of a 15-point difference in means between two groups:

• depends on the spread of scores in each group

• depends on the shape of the frequency polygons

• depends on the number of cases in each group

• all of the above

Most researchers consider that any delta of .50 or larger is an important finding.

• True

• False