Assignment 4 – Correlations

Answer the following:

1. A correlation measures the _________ and __________ of the relationship between two variables.

2. Explain in detail why one cannot infer causation from correlation.

3. Briefly describe what a coefficient of determination is and why a researcher would be interested in this value.

4. Provide examples of the following using hypothetical variables and a made up correlation to illustrate your point:
a. Strong positive (direct) correlation
Construct your response like the example given here: A strong positive correlation exists between study time and GPA (r = .74). That is, as study time increases so does GPA.
b. Weak positive correlation
c. Strong negative (inverse) correlation
d. Weak negative correlation

Conduct a correlational analysis on the following example:

Example: A school psychologist is interested in determining if test anxiety is affecting her students’ performance on their exams. She randomly selected 103 students from her school and conducted a correlational analysis to try and answer her question. She hypothesized that as anxiety increases, test performance decreases.

Based on this example answer the following questions:

1. Why is a correlational analysis the most appropriate technique to test her hypothesis?