Lesson 837 of 1524
Hypothesis Testing with Two Samples
The comparison of two independent population means is very common and provides a way to test the hypothesis that the two groups differ from each other.
Practice this chapterThe comparison of two independent population means is very common and provides a way to test the hypothesis that the two groups differ from each other. An observed difference between two sample means depends on both the means and the sample standard deviations.
Very different means can occur by chance if there is great variation among the individual samples. The test statistic will have to account for this fact.
Cohen’s d — a measure of effect size based on the differences between two means. If d is between 0 and 0.2 then the effect is small. If d approaches is 0.5, then the effect is medium, and if…. Independent Groups — two samples that are selected from two populations, and the values from one population are not related in any way to the values from the other population. Matched Pairs — two samples that are dependent. Differences between a before and after scenario are tested by testing one population mean of differences. Pooled Variance — a weighted average of two variances that can then be used when calculating standard error.
Be able to calculate Cohen’s d and interpret it.
Worked example
What does “Cohen’s d” mean in Hypothesis Testing with Two Samples?
- 1Use the wording this chapter gives for Cohen’s d.
- 2The book says: a measure of effect size based on the differences between two means. If d is between 0 and 0.2 then the effect is small. If d approaches is 0.5, then the effect is medium, and if….
- 3Do not use the meaning of Independent Groups. That term means two samples that are selected from two populations, and the values from one population are not related in any way to the values from the other population.
Result: a measure of effect size based on the differences between two means. If d is between 0 and 0.2 then the effect is small. If d approaches is 0.5, then the effect is medium, and if…
Why. That is the meaning this chapter gives for Cohen’s d.
Do not swap Cohen’s d and Independent Groups. Cohen’s d means a measure of effect size based on the differences between two means. If d is between 0 and 0.2 then the effect is small. If d approaches is 0.5, then the effect is medium, and if…. Independent Groups means two samples that are selected from two populations, and the values from one population are not related in any way to the values from the other population.
Practice margin
This chapter
A fresh set from this chapter only. Choose 10 or 20. Multiple choice and fill-in, with no repeat inside the set.