1 An independentmeasures study produces sample means of M1

1. An independent-measures study produces sample means of

M₁ = 35 and M₂ = 31 and a pooled variance of 25.

For this study, Cohen’s d = ____.

2.

A sample of n = 16 scores produces a t statistic of t = 2.00.

If the sample is used to measure effect size with ²,

what value will be obtained for ²?

3.

The data from an independent-measures research study

produce a sample mean difference of 6 points,

and an estimated standard error of 2 points.

If there are n = 8 scores in each sample,

then the value for the t statistic is ____.

4.

A repeated-measures study comparing two treatments,

with a sample of n = 4 participants,

a mean difference of M = 4 and a variance of 4 for the difference scores.

What is the estimated standard error for the sample mean difference?

Solution

1. Cohen\'s d = M1-M2 /sd = 35-31/25 =0.16;

2.cohen\'s d =1.0328; effect size = 0.45883

3. t =6/2 =3 ; df =7

4. estimated standar error = sd /sqrt(n) =2/ sqrt(4) = 1

.