Question

In a study, researchers are interested in how color and location influences people’s ability to identify objects.

In the task, participants were shown photographs of objects and asked to name the object in the photograph as quickly as possible. The pictures were presented one at a time, and participants’ response time to name each picture was recorded.

For each participant, half of the pictures were in black and white, and the other half were in color.

Half of the participants did the task in a small classroom, and the other half of participants did the task in a large classroom.

The means for the study were:

Small classroom participants, color trials = 1000 milliseconds

Small classroom participants, black and white trials = 1500 milliseconds

Large classroom participants, color trials = 500 milliseconds

Large classroom, black and white trials = 600 milliseconds

Practice Questions:

1. What is the dependent variable?

2. Identify each independent and/or subject variable. Report how many levels each has and name the levels.

3. Is this a single-factor or a factorial design? Explain your answer.

4. Identify which variables, if any, are within subjects. Explain your answer.

5. Identify which variables, if any, are between subjects. Explain your answer

6. What is the notation for this experiment?

7. How many conditions does this study have? Explain how you determined this.

8. If the experimenters ran 100 participants in each condition, what was the total number of participants used? Explain your answer.

9. Create a factorial matrix for the study (include the means for each cell of the matrix).

10. Calculate the marginal means, and add those to the matrix. (Show your work here—that is show what your calculations were.)

11. Assume that differences of more than 150 milliseconds are significant. Based on a visual inspection of the data, does it look like there are any significant main effects in this study? Explain why or why not?

12. Assume that differences of more than 150 milliseconds are significant. Based on a visual inspection of the data, does it look like there is a significant interaction in this study? Explain why or why not?

13. What would be the appropriate statistical analysis to perform on this data to test for main effects and the interaction?

Answer 1

1. The dependent variable is the ability to identify objects.

2. The independent variables are colour (2 levels: black and white; color) and location (2 levels: small classroom; large classroom).

3. This is a factorial design. A factorial design is one which comprises of two or more independent variables. In this study, we have two independent variables which are color and location.

4. There are no within subject variables in the study. None of the participants have been exposed to all the levels of a specific independent variable. It has been mentioned that half the participants were assigned to one level whereas the other half were assigned to another level.

Please post the other questions separately. As per our answering guidelines we are supposed to answer just one question or four sub parts of the same question.