Inferential statistics

A

How is sample size related to statistical tests and outcomes? Give a specific example. Why is it important to plan the sample size before collecting data?

B

Fill in the following for a possible study with one independent variable (IV) with two conditions/treatments and a dependent variable (DV) that is measured on a continuous scale (interval or ratio):

·  Independent variable = ______________

· Condition A = ______________

· Condition B = ______________

· Dependent variable = _______________

· How do you know this DV is measured on a continuous scale?

· How would you word the null hypothesis for your sample study?

· How would you word the alternative hypothesis for your sample study?

· What alpha level would you set to test your hypothesis? Why?

MODULE 3

A

What is the primary purpose of inferential statistics? How might inferential statistics be applied to your intended research study? Explain.

B

Researchers often assume a normal distribution of data. Why is this significant in quantitative research? Explain.

MODULE 4

A

Mary is planning a study to see if learning of 6th graders on a math lesson is affected by background noise level. She wants to use a t-test for independent groups to analyze her results. Help her plan her study. What is her independent variable (IV) here? Describe two conditions she could create for the IV in her study. What is her dependent variable (DV) here? Describe a way to measure the DV so that each participant would have one score at the end. Would this DV measure be on a continuous scale of measurement? Why is this important? Explain and justify.

B

Consider Mary’s experiment regarding whether learning of 6th graders on a math lesson is affected by background noise level. Mary has collected her data. What is the null hypothesis for her study? What is the alternative hypothesis for her study? What are the assumptions that must be met about her data before she can correctly use an independent t-test to test the hypotheses? Why? How would she see if her data met these assumptions? How much room does she have to violate any of these assumptions and still get accurate results from the t-test? Explain and support your answers.

MODULE 5

A

In Module 4, we considered Mary’s interest in doing a study to see if learning of 6th graders on a math lesson is affected by background noise level. There, she was planning to use two noise conditions and then analyze her outcomes using a t-test for independent groups. Describe the study Mary might plan where she would use a one-way analysis of variance (ANOVA) for independent groups instead of a t-test to study differences between noise levels. What is her independent variable here? Describe the conditions she could create for this study. What is her dependent variable? Describe a way to measure the DV so that each participant would have one score at the end that would be on a continuous scale of measurement. Support your responses.

B

Consider Mary’s study of whether the learning of 6th graders on a math lesson is affected by background noise level. Describe the pros and cons of Mary using a repeated measures design for this study. What would you probably choose to do? Support your responses.