Question

In: Statistics and Probability

Suppose I calculate the Cohen’s d for the difference between 2 means and find that it...

Suppose I calculate the Cohen’s d for the difference between 2 means and find that it is very small—that is, the two means are very close together. Do I know if the 2 means are not significantly different?

Expert Solution

Suppose, corresponding random variables be X and Y.

Test statistic is given by

Cohen's d is given by

In general,

Thus we observe that, value of test statistic is higher than that of Cohen's d (in general). So, small value of Cohen's d does not imply small value of test statistic. Thus value of test statistic may be significantly larger (than critical value) implying significant difference between two means.

Hence, we cannot conclude explicitly about difference of two means (whether significant or not) without knowing sample sizes (in particular, little difference between sample means in case of higher sample sizes produce the conclusion that obtained difference is statistically significant).

orchestra answered 1 year ago

what is the difference between Cohen’s d and eta^2? In one way ANOVA, two way ANOVA,...

what is the difference between Cohen’s d and eta^2? In one way ANOVA, two way ANOVA, and repeated measures ANOVA is cohen’s d only used for one way ANOVA and repeated measures ANOVA?

2. Suppose that we want to test for the difference between two population means. Explain under...

2. Suppose that we want to test for the difference between two population means. Explain under what conditions we would use the t-test and under what conditions we would use the z-test. Explain the differences between the two tests. Type all your answers. Try to write at least one page

Suppose independent random samples that are taken to test the difference between the means of two...

Suppose independent random samples that are taken to test the difference between the means of two populations (n1 = 66 and n2 =46). The variances of the populations are unknown but are assumed to be unequal. The sample standard deviations are s1=82 and s2=68. The appropriate distribution to use is the: A) t distribution with df = 110 B ) t distribution with df = 107 C) t distribution with df = 106 D) F distribution with numerator df =...

---Find the 98% confidence interval for the difference between two means based on this information about...

---Find the 98% confidence interval for the difference between two means based on this information about two samples. Assume independent samples from normal populations. (Use conservative degrees of freedom.) (Give your answers correct to two decimal places.) Sample Number Mean Std. Dev. 1 18 40 30 2 17 28 25 Lower Limit Upper Limit ---Find the value of t for the difference between two means based on an assumption of normality and this information about two samples. (Use sample 1...

Consider the following statements. (i). If we are testing for the difference between two population means,...

Consider the following statements. (i). If we are testing for the difference between two population means, it is assumed that the sample observations from one population are independent of the sample observations from the other population. (ii). If we are testing for the difference between two population means, it is assumed that the two populations are approximately normal and have equal variances. (iii). The critical value of t for a two-tail test of the difference of two means, a level...

Question 2 What is the difference, if any, between the standard deviation of the sample means...

Question 2 What is the difference, if any, between the standard deviation of the sample means and the standard error of the sample means? Discuss

What is the difference between a test of independent means and a test of dependent means,...

What is the difference between a test of independent means and a test of dependent means, and when is each appropriate?

Suppose you run a completely randomized expirement. Prove that the difference in sample means between treatment...

Suppose you run a completely randomized expirement. Prove that the difference in sample means between treatment and control groups is an unbiased estimator of the average treatment effect.

What experiment can I used in order to find the difference between macropinocytosis and phagocytosis in...

What experiment can I used in order to find the difference between macropinocytosis and phagocytosis in a cell ? ( and I know actin is present)

1.Explain the difference between subsidized and unsubsidized student loans. 2.Explain what it means to capitalize the...

1.Explain the difference between subsidized and unsubsidized student loans. 2.Explain what it means to capitalize the student loan. Is this an option for both subsidized and unsubsidized loans? What does it mean if you don't capitalize your student loan? (please use appropriate grammar, complete sentences, and that you explain yourself completely. This will mean there should be at least a couple sentences for each explanation.)