Sample Size / Power Analysis

Sample Size, Effect Size, Statistical Power, and Significance Level

Power Analysis

Each of these four components of your study are a function of the other three, meaning that altering one causes changes in the others. The complex synergy of this relationship has been the focus of numerous scholarly articles, authored by some of the brightest minds in the field of statistical analysis. At Statistics Solutions our professional statisticians understand this relationship and know how to help you understand this relationship.

It is not uncommon for statistics consultants to inappropriately take a "one-size-fits-all" approach in determination of these components for your study. At Statistics Solutions our professional statisticians will determine the ideal sample size for your study and justify that sample size. In addition, we will determine the appropriate Effect Size, Power, and Significance Level for your study, ensuring a smooth transition from theory to practice. At Statistics Solutions we understand that this may be or has been the largest undertaking of your life and will work closely with you in the completion of this crowning achievement.

Sample Size

Sample size is critical to ensuring the validity of your study. Ideally, your sample size will be determined a priori, however, the professional statisticians at Statistics Solutions can work with and justify any data to help you make meaningful inferences. With our experience and expertise gained from completing thousands of dissertations and projects, it is possible for us to justify "less-than-ideal" sample sizes and still make your dissertation great.

Effect Size

The Effect Size of your study is critical in the synergy of Sample Size, Power, and Significance Level. It is unique to the analysis and your focus of the study. This unique measurement will tell you the strength or size of a particular relationship. The professional statisticians at Statistics Solutions will ensure that an appropriate Effect Size is chosen for your study a priori, or determined in post hoc analysis.

Power

This measurement is your probability of committing a Type II error. Restated, it is the probability of not finding a relationship that exists in your analysis. While there are general guidelines as to what is appropriate, the a priori power is unique to you and every study conducted. The professional statisticians at Statistics Solutions will determine the appropriate power, as well as conduct post hoc analysis to determine the Power after the fact.

Significance Level

The alpha or significance level of your study is the probability of committing a Type I error. More simply stated, it is your probability of finding a relationship that does not exist. Generally considered more severe than committing a Type II error, this measurement is unique to your study. The Significance Level for a study involving airbag deployment failures would not be the same as the Significance Level for a study involving the satisfaction of five-year-old children with a particular brand of red crayon. The professional statisticians at Statistics Solutions will determine the appropriate Significance Level for your study, ensuring meaningful, defendable results that are easy to write about and easy to understand.