# research statistics

For each question below please provide a 2-3 paragraph response (do not exceed one page for any question) Responses should utilize double spacing, one inch margins, and APA style and citations as needed.

1. What are three strengths and three weaknesses of the following quasi-experimental design? Additionally, please describe a research scenario/example for which this design might be useful. (10 points)

Interrupted Time Series Design: O O O O X O O O O

1. What are three strengths and three weaknesses of the following experimental design? Additionally, please describe a research scenario/example for which this design might be useful. (10 points)

Basic Randomized Design: (R) X O

(R) O

1. What are three strengths and three weaknesses of the following experimental design? Additionally please describe a research scenario/example for which this design might be useful. (10 points)

Pretest-Posttest Comparison Group Design: (R) O Xa O

(R) O Xb O

1. What is attrition and why is it a threat to internal validity? How does it jeopardize a researcher’s ability to understand outcomes? (10 points)
1. What is unreliability of treatment implementation and why is it a threat to statistical conclusion validity? How does it jeopardize a researcher’s ability to understand program effects/outcomes? (10 points)
1. What is construct validity as it pertains to measures? Why is it important for a measure/scale to have strong construct validity? How do scale developers establish/demonstrate construct validity (10 points)
1. What is the difference between a probability sampling strategy and a nonprobablility sampling strategy? What are the advantages and disadvantages of each strategy? Describe one specific example/type of each strategy. (10 points)
1. Describe a qualitative method of data collection. Describe three advantages and three disadvantages of the method. Describe a quantitative method of data collection. Describe three advantages and three disadvantages of the method. (10 points)

9. Read the following case study and indicate which ethical principle is violated. Explain why. (10 points)

A psychologist decided to conduct a survey study on marital conflict over the Internet. She posted an explanation of the study on a university Web site. Those who wished to participate were asked to download the questionnaire into their personal computers and to e-mail their responses back to the psychologist. The explanation on the Web site claimed that participant responses were anonymous and thus there were no risks to confidentiality. However, the psychologist’s university did not have the technology necessary to de-identify respondent e-mail addresses, so in fact there was a chance than an e-mail address might be recognized by the psychologist, a research assistant, or others. In addition, the Web site explanation did not warn participants to password protect the completed file saved on their personal computer.

10. What is the difference between descriptive statistics and inferential statistics? Give two examples of statistical tests/analyses for each and describe what information each test/analysis yields. (10 points)