Stats 210 Exam 2 questions with verified
answers already passed
Confidence Interval - correct answer ✔✔An interval estimate based on
a sample statistic; it includes the population mean a certain percentage
of the time if the same population is sampled from repeatedly
As sample size increases, what happens to the test statistic? - correct
answer ✔✔The test statistic increases
Effect Size - correct answer ✔✔indicates the size of a difference and is
unaffected by sample size. Tells us how much two populations do not
overlap. The less overlap the biggest the effect size
How to decrease amount of overlap between two distributions - correct
answer ✔✔1- When means are further apart, overlap decreases and
effect size increases
2- overlap decreases and effect size increases when variability within
each distribution scores is smaller
Cohen's d - correct answer ✔✔A measure of effect size that assesses
the difference between two means in terms of standard deviation, not
standard error
, Cohen's d conventions - correct answer ✔✔Small- .2 overlap- 85%
Medium- .5 overlap-67%
Large- .8 overlap- 53%
meta-analysis - correct answer ✔✔is a study that involves the
calculation of a mean effect size from the individual effect sizes of more
than one study
Statistical Power - correct answer ✔✔A measure of the likelihood that
we will reject the null hypothesis, given that the null hypothesis is false.
Probability we will not make a type II error
What is the minimum value for power analysis? - correct answer
✔✔80%, 80% chance of correctly rejecting the null
What are the five factors that affect statistical power? - correct answer
✔✔1- increase the alpha (also increases chance of type I error)
2- Turn a two-tailed hypothesis into a one-tailed hypothesis.
3- Increase N. Increasing sample size leads to an increase in the test
statistic, making it easier to reject the null hypothesis.
4- Exaggerate the mean difference between levels of the independent
variable. As the difference between means becomes larger, there is less
overlap between curves. Less overlap means more statistical power
answers already passed
Confidence Interval - correct answer ✔✔An interval estimate based on
a sample statistic; it includes the population mean a certain percentage
of the time if the same population is sampled from repeatedly
As sample size increases, what happens to the test statistic? - correct
answer ✔✔The test statistic increases
Effect Size - correct answer ✔✔indicates the size of a difference and is
unaffected by sample size. Tells us how much two populations do not
overlap. The less overlap the biggest the effect size
How to decrease amount of overlap between two distributions - correct
answer ✔✔1- When means are further apart, overlap decreases and
effect size increases
2- overlap decreases and effect size increases when variability within
each distribution scores is smaller
Cohen's d - correct answer ✔✔A measure of effect size that assesses
the difference between two means in terms of standard deviation, not
standard error
, Cohen's d conventions - correct answer ✔✔Small- .2 overlap- 85%
Medium- .5 overlap-67%
Large- .8 overlap- 53%
meta-analysis - correct answer ✔✔is a study that involves the
calculation of a mean effect size from the individual effect sizes of more
than one study
Statistical Power - correct answer ✔✔A measure of the likelihood that
we will reject the null hypothesis, given that the null hypothesis is false.
Probability we will not make a type II error
What is the minimum value for power analysis? - correct answer
✔✔80%, 80% chance of correctly rejecting the null
What are the five factors that affect statistical power? - correct answer
✔✔1- increase the alpha (also increases chance of type I error)
2- Turn a two-tailed hypothesis into a one-tailed hypothesis.
3- Increase N. Increasing sample size leads to an increase in the test
statistic, making it easier to reject the null hypothesis.
4- Exaggerate the mean difference between levels of the independent
variable. As the difference between means becomes larger, there is less
overlap between curves. Less overlap means more statistical power
