a non-directional hypothesis and have set your alpha at .01. You have 30 pairs of scores. What is the criterion value of r you need to equal or exceed to have a significant correlation so you can reject the null hypothesis
To determine the criterion value of r (correlation coefficient), you will require the critical value for the chosen alpha level (α) and the degrees of freedom.
Here's how you can calculate the criterion value of r:
1. Determine the degrees of freedom: Since you have 30 pairs of scores, the degrees of freedom will be N - 2, where N is the total number of pairs. In this case, degrees of freedom = 30 - 2 = 28.
2. Find the critical value of r: You can look up the critical value of r for a two-tailed test at the chosen alpha level (.01 in this case), along with the degrees of freedom (28). Critical values table or statistical software can help you find this value.
3. Reject or fail to reject the null hypothesis: Compare the absolute value of the calculated correlation coefficient (r) with the critical value of r from step 2. If your calculated r is larger than or equal to the critical value, you can reject the null hypothesis and conclude a significant correlation. Otherwise, if the calculated r is smaller than the critical value, you fail to reject the null hypothesis and conclude no significant correlation.
Remember, the critical value is specific to your chosen alpha level and degrees of freedom. Make sure to refer to the proper statistical table or use statistical software to find the precise critical value.