SPSS Assignment 5 (out of 6): One-Way ANOVA
Research Methods in Psychology A (HPS201/HPS771)
Laboratory Assignment
One-Way ANOVA
______________________________________________________________
**** ASSIGNMENT 5: One-Way ANOVA QUESTIONS ****
Experiment
Jurors place heavy weight on eyewitness testimony when deciding whether a suspect is guilty. Legal evidence suggests that jurors tend to give more weight to the testimony of eyewitnesses who report that they were confident in remembering the event. (http:
www.scientificamerican.com/article/do-the-eyes-have-it/) Still, there is mixed evidence in the literature whether the confidence with which people remember an event is related to the accuracy of their memories. Your task as a researcher is to clarify this. To this end, you show a crime scene to 33 randomly selected individuals. You then count the number of mistakes they make in recalling the crime scene. Finally, you ask participants to rate how confident they were in recalling the crime scene. Based on their ratings, you assign each participant to either the low confidence group (n = 11), the medium confidence group (n = 11) or the high confidence group (n = 11). You then run a one-way ANOVA to test if the three groups differ in the number of mistakes made when recalling the crime scene. You obtain the following output from the analysis:
_____________________________________________________________
Questions
Note that these questions do not require SPSS output.
1. Complete the table below. (2 Marks)
Source
SS
df
MS
F
Between Groups (Treatment)
3
Within Groups (E
or)
60
Total
2. What is the Partial eta squared for this research scenario (1 mark)?
3. Is the ANOVA statistically significant? Justify your response (1 mark)
4. Assume you are a Forensic Psychologist. What would be your advice to jurors based on the results of the above research? Justify your response. (2 Marks)
5. In the present study, the three groups could have been compared using t-tests. Why is it more appropriate to analyze the data from the experiment using a one-way ANOVA? (2 Marks)
6. Describe a research scenario where both t-test and One-way ANOVA would be equally as appropriate to address a research question. Justify your response (2 marks).
TOTAL: /10 Marks
1