To Err is Human: What are Type I and II Errors?

The Power Advantage of Within-Subjects Designs

When to use descriptive Statistics to answer RQs

Descriptive statistics are the appropriate analyses when the goal of the research is to present the participants’ responses to survey items in order to address the research questions.  There are no hypotheses in descriptive statistics. ·     Descriptive statistics include: frequencies and percentages for categorical (ordinal and nominal) data; and averages (means, medians, and/or ranges) and

Sample Size Justification

Students typically struggle with sample size justification, in part because there are 2 types.  One type is based on the population and the second based on a power analysis.  Sample size based on a population is generally not used in dissertations.  It not used in dissertations because the requirement would too exhaustive to stratify the

Sample Size in Plain English

As a dissertation consultant for over 20 years, I consistently see confusion when it comes to answering a simple question—how many participants do in need? The confusion is reasonable because most programs do not even offer a class in sample size and leave it to the graduate student to figure it out on their own.

Statistical Power

One can interpret or conjecture about data statistically, with the help of statistical inference. Thus, statistical inference is to infer about something statistically. Statistical inference basically involves Estimation and Testing of Hypothesis. Since our discussion involves Statistical Power, we shall discuss Testing of Hypothesis. Hypothesis Testing consists of null and alternative hypothesis, typically denoted as