Question

1. Researchers obtained a sample of 36 college students who all have the same history instructor this semester. Half of the students were shown a 2-min video that claimed the purpose of education was to help students “learn how to learn” so that they can enjoy a lifetime of learning after college. other half of students were shown a 2-min video that claimed the purpose of education was to teach facts to students. After watching the 2-min videos, the students were asked to rate their history instructor using a 10-point scale, 1 = very bad teacher to 10 = very good teacher. The mean and standard deviations for each group of 18 students are provided below. Use the provided information to answer the next four questions. Use an α of .05, two tailed.

“learn to learn” Group 1: M₁ = 5.9, SD₁ = 1.8, n₁ = 18

“learn facts” Group 2: M₂ = 7.2, SD₂ = 1.7, n₂ = 18

Compute the effect size of this study.

	a.	6.13
	b.	4.93
	c.	2.04
	d.	3.07
	e.	.058
	f.	0.74
	g.	0.34

2. Researchers obtained a sample of 36 college students who all have the same history instructor this semester. Half of the students were shown a 2-min video that claimed the purpose of education was to help students “learn how to learn” so that they can enjoy a lifetime of learning after college. The other half of students were shown a 2-min video that claimed the purpose of education was to teach facts to students. After watching the 2-min videos, the students were asked to rate their history instructor using a 10-point scale, 1 = very bad teacher to 10 = very good teacher. The mean and standard deviations for each group of 18 students are provided below. Use the provided information to answer the next four questions. Use an α of .05, two tailed.

“learn to learn” Group 1: M₁ = 5.9, SD₁ = 1.8, n₁ = 18

“learn facts” Group 2: M₂ = 7.2, SD2 = 1.7, n₂ = 18

How large is the effect size?

	a.	small
	b.	small-medium
	c.	medium
	d.	medium-large
	e.	large

3. Researchers obtained a sample of 36 college students who all have the same history instructor this semester. Half of the students were shown a 2-min video that claimed the purpose of education was to help students “learn how to learn” so that they can enjoy a lifetime of learning after college. The other half of students were shown a 2-min video that claimed the purpose of education was to teach facts to students. After watching the 2-min videos, the students were asked to rate their history instructor using a 10-point scale, 1 = very bad teacher to 10 = very good teacher. The mean and standard deviations for each group of 18 students are provided below. Use the provided information to answer the next four questions. Use an α of .05, two tailed.

“learn to learn” Group 1: M₁ = 5.9, SD₁ = 1.8, n₁ = 18

“learn facts” Group 2: M₂ = 7.2, SD₂ = 1.7, n₂ = 18

Compute 95% CI for the mean difference between the “learn how to learn” and “teach facts” groups.

	a.	[−2.49, −0.11]
	b.	[−2.06, 0.54]
	c.	[−2.29, −0.31]
	d.	[0, 2.60]
	e.	[−3.38, −0.77]

Answer 1

Given that  

“learn to learn” Group 1: M₁ = 5.9, SD₁ = 1.8, n₁ = 18

“learn facts” Group 2: M₂ = 7.2, SD₂ = 1.7, n₂ = 18

Cohen’s d effect size   

Where

  

Cohen’s d effect size   

The absolute value of of d=0.74

For the given data Cohens d effect size is 0.74

The value is between 0.6-0.8 So it The effect is Large

3)

The confidence interval forthe mean dffierence is

Where

  

  

Given that level of siginificance %

The degrees of freedom is n₁+n₂+-2=18+18-2=34

The Table value for t_5,34 is 1.691

M₁-M₂=5.9-7.2=-1.3

The value of

The confidence interval is