1.  Research Designs 

   QUESTION

   Between-Groups Design
   In the between-groups design, researchers were interested in whether cholesterol levels would differ depending on diet. Twenty participants were randomly assigned to one of two different groups. Group A was assigned a diet rich in fruits and vegetables and with no trans fats. Group B participants were asked to follow their normal diets, which contained varying levels of trans fats depending on the individual. After one month, blood samples were drawn and the following levels of cholesterol were obtained:

   Participant

   Blood Cholesterol

   Diet

   1

   129

   Healthy

   2

   98

   Healthy

   3

   150

   Healthy

   4

   75

   Healthy

   5

   135

   Healthy

   6

   175

   Healthy

   7

   115

   Healthy

   8

   103

   Healthy

   9

   156

   Healthy

   10

   143

   Healthy

   11

   239

   Normal

   12

   500

   Normal

   13

   350

   Normal

   14

   468

   Normal

   15

   198

   Normal

   16

   213

   Normal

   17

   225

   Normal

   18

   175

   Normal

   19

   560

   Normal

   20

   289

   Normal

   Within-Subjects Design
   In the within-subjects design, researchers were interested in whether participants could lower their cholesterol levels by changing from a diet higher in trans fats to one with no trans fats. Ten research participants were selected. A baseline measure of cholesterol was taken from each. They were then put on a diet rich in fruits and vegetables and devoid of trans fats for one month. At the end of that month, blood cholesterol was again measured, and the following results were obtained:

   Participant

   Blood Cholesterol

   Diet

   1

   129

   Baseline

   1

   98

   Healthy

   2

   150

   Baseline

   2

   75

   Healthy

   3

   175

   Baseline

   3

   135

   Healthy

   4

   115

   Baseline

   4

   103

   Healthy

   5

   156

   Baseline

   5

   143

   Healthy

   6

   500

   Baseline

   6

   450

   Healthy

   7

   468

   Baseline

   7

   350

   Healthy

   8

   198

   Baseline

   8

   213

   Healthy

   9

   225

   Baseline

   9

   175

   Healthy

   10

   560

   Baseline

   10

   481

   Healthy

   In a Microsoft Word document, answer the following questions:
   What is the independent variable in the study for a Between-Subject Design? What are the levels of that independent variable? What is the dependent variable?
   What is the independent variable in the study for a Within-Subject Design? What are the levels of that independent variable? What is the dependent variable?
   Name this document SU_PSY2008_W5_A_ LastName_FirstInitial
   Based on what you learned in your lecture on Data Files for Between- and Within-Subject Designs , create a data file in Microsoft Excel that will enable you to conduct a between-subject analysis of this data.
   On a separate tab within your Microsoft Excel file (click the + sign at the bottom to create a new worksheet) create a data file that will enable you to conduct a within-subjects’ analysis of this data.

Related Samples