# Evaluate Sampling Method And Sample Size

**Instructions**

This assignment consists of three parts:

(1) **Sample Selection **

Recommend the steps that should be taken to draw the particular sample described below. Format your response as a procedure.

- A stratified sample of 75 doctors, 75 lawyers and 75 engineers who belong to a professional organization in that you belong to.
- A simple random sample of 150 subscribers to your local newspaper.
- A systematic sample of 250 subscribers from a subscriber list of a trade publication.

(2) **A Priori Power Analysis **

Download the G*Power software provided, and then use the software to submit the following:

a. Calculate the estimated sample size needed when given these factors:

- one-tailed t-test with two independent groups of equal size
- small effect size (see Piasta, S.B., & Justice, L.M., 2010)
- alpha =.05
- beta = .2 (Reminder: Power = 1 – beta)
- Assume that the result is a sample size beyond what you can obtain. Use the compromise function to compute alpha and beta for a sample half the size.
- Indicate the resulting alpha and beta.
- Analyze the result and decide if the study should be conducted with a smaller sample size. Explain your rationale.
- In the context of Type I and Type II error.
- Include a visual of the G* Power output matrix.

b. Calculate the estimated sample size needed to perform an ANOVA (fixed effects, omnibus, one-way) when given these factors:

- ANOVA (fixed effects, omnibus, one-way)
- small effect size
- alpha =.05
- beta = .2
- 3 groups
- Include a visual of the G* Power output matrix.

(3) **Intended Research Sampling Method**

Describe the sampling method that would be appropriate for your intended research.

- Outline the problem statement, purpose statement, and research questions.
- Describe the population of interest (also referred to as the theoretical population).
- Identify the sampling frame to be used to recruit participants.
- List criteria to be met for an interested person to participate in the research study.
- Compute an estimated sample size.
- Describe the recruitment procedure that might be used to draw the actual sample.

Length: Your paper should be between 5 – 10 pages not including title and reference page. Results of the G* power analysis that will add length to the paper.

References: Include a minimum of five (5) scholarly sources.