A comparison of the 4^th grade students who were taught methods to increase their classroom participation are compared to a group of students who did not receive the classroom participation training on a reading subscale of an academic achievement test using an eta- squared (²) effect size. The SS_Treatment = 1110.050 and the SS_Error = 664.900. Use the illustration in Chapter 3 to calculate the (²) effect size and choose the correct answer below.

Group of answer choices

What is the strength of the eta- squared (²) effect size in the example above according to Cohen's convention.