Exam 15: Statistical Evaluation of Data

For scores measured on a nominal scale of measurement (e.g., job classification), which measure of central tendency is appropriate?

When a research report demonstrates a significant treatment effect at the .05 level, you can be more confident that the effect is real than if the researcher had reported a significant effect with an alpha level of only .01.

Values such as Cohen's d or r ² (the percentage of variance accounted for) are used to measure ____.

In a frequency distribution graph, the frequencies are listed on the vertical axis.

Under what circumstances is a very small treatment effect still likely to be statistically significant?

Without some correction, such as the Spearman-Brown formula, a correlation measuring split-half reliability will tend to overestimate the reliability for the full test.

Which technique is for estimating the magnitude of an unknown population parameter?

A study with 50 research participants has a degree of freedom of ________.

If a distribution of numerical scores contains one or two extremely high values, compared to the rest of the scores, which measure of central tendency would produce the most representative value?

The goal of descriptive statistics is to simplify, summarize, and organize data.

A researcher reports a significant correlation using an alpha level of .01. In this situation, the probability that the researcher is making a ____.

Explain the concept of statistical significance . Be sure that the concept of an alpha level is included in your explanation.

The concept of degrees of freedom is associated with the ____.

In general, a sample with large variance is more likely to produce a significant result than a sample with small variance.

In general, a correlation obtained from a large sample is more likely to be significant than a correlation obtained from a small sample.

Which general category of statistical methods is intended to answer questions about populations by using sample data?

For data that consist of two or more groups of scores with each score a numerical value measuring the same variable, the most common statistics are those that measure and evaluate the mean differences between groups.

Which combination of factors is most likely to result in a significant outcome for a hypothesis test?

The most commonly used descriptive statistics for a set of numerical scores are the mean and the ____.

Statistical techniques that summarize, organize, and simplify data are best classified as ____ statistics.