Question

A researcher wishes to examine whether time of day (morning versus afternoon) affects the memory of older and younger participants. He obtains a sample of 40 older individuals and 40 younger individuals and gives them a passage to read. They are later given a test over the passage (scores on the test could range from 0 to 30). Half of the individuals are randomly assigned to read the passage and take the test in the morning, and the other half do so in the afternoon. The data are reported in the table below (the numbers represent mean test scores for each group).

	Morning Testing	Afternoon Testing
Older Adults	M=15	M=8
Younger Adults	M=16	M=20

1. Name one independent variable.

a. Is this IV manipulated or not manipulated by the researcher?

b. Does this IV represent independent groups or correlated groups?

c. How many levels does this IV have?

2. Name the other independent variable

a. Is this IV manipulated or not manipulated by the researcher?

b. Does this IV represent independent groups or correlated groups?

c. How many levels does this IV have?

3. Name the dependent variable.

4. What is the scale of measurement for the dependent variable?

5. Does there appear to be a main effect of time of day? (Note: You are not given any inferential statistics to be able to definitively determine whether there is a main effect. Examine the means and try to determine if they are different or similar to each other).

Answer 1

1. Time of the day is one independent varibale.

A. It is manipulated by the researcher with respect to two timings.

B. This IV represents correlated groups as opposed to independent groups as it given the research the liberty to manipulate and use groups of subjects.

C. The levels this IV has are two, which is morning and afternoon.

2. The other IV is Reading passage

A. It isn't manipulated, only upto the extent of selecting the passage.

B. Correlated groups as well, as there are groups of subjects used with respect to the reading passage.

C. Only on level.

3. The DV is the memory and learning of the individuals.

4. The scale of measurement is a test.

5. In my opinion, it is not the time of day that affects their learning but the passage of time between the passage read and the test given.