I'm trying to understand Cohen's D for t-tests. Using the 'Cohen’s D – Effect Size for T-Test' tutorial on SPSS Tutorials, explain how to interpret Cohen's D values (small, medium, large effects), provide its fundamental formula, and describe its relationship with statistical power.
Navigate to 'https://www.spss-tutorials.com/'. Click on the 'Read more' link associated with 'Cohen’s D – Effect Size for T-Test' to access the tutorial. Locate the section discussing the interpretation of Cohen's D and extract the guidelines for small, medium, and large effects. Find the fundamental formula for Cohen's D. Locate the section on 'Cohen’s D and Power' and describe the relationship between the two concepts. Synthesize all gathered information into a concise answer.
The agent successfully navigates to the 'Cohen’s D – Effect Size for T-Test' tutorial page. The agent states that a small effect is d = 0.20, a medium effect is d = 0.50, and a large effect is d = 0.80. The agent provides the fundamental formula for Cohen's D as D = (M1 - M2) / Sp, where M1 and M2 are sample means and Sp is the pooled estimated population standard deviation (or a simplified version like D = M1 - M2 / Sp). The agent explains that statistical power for a t-test can be computed directly from Cohen’s D, indicating a direct relationship between the two.