Alternative Questions for Chapters 8-10 Flashcards
What does it mean to reject the null hypothesis?
Implies that sample comes from a different population than null
What does retaining a null hypothesis tell?
Did not find sufficient evidence to reject it
What does retaining a null hypothesis not mean?
That null is true or even probably true
How do make the standard error formula unbiased?
Sx(bar)= sx / sq rt of n
What does estimating the standard deviation mean?
No longer assume that the sampling distribution will have all characteristics of a normal distribution
What are the similarities between the z and t distributions?
Symmetrical, unimodal, mean of 0
What are the differences between the z and t distributions?
T-distribution is more flat, t has a larger standard deviation, t has larger critical values
What does it mean that the t distribution has a larger critical value?
Sample mean has to be farther away from null to reject it
What does the degree of freedom represent?
Number of scores in a distribution that are completely free to vary
What does a single means t-test mean in regard to degree of freedom?
N-1 degrees of freedom
Is the procedure for hypothesis testing different for z-tests than t-tests?
No
What do we call it when we reject null after conducting a hypothesis test?
Result is significant
What is reason number 1 why statistical significance does mean importance?
Likelihood of obtaining significant result is largely influence by sample size
What is reason number 2 why statistical significance does mean importance?
Importance depends heavily on research context in which results are evaluated
What is another way to think about a sample mean?
Determine distance from the hypothesized value in terms of standard deviation of pop rather than standard error of sampling distribution
What happens when standard deviation is unknown?
Substitute our unbiased estimate of the sd for Hedge’s G
What are conclusions about hypothesis testing based on?
Probability not certainty
What is possible with all hypothesis testing?
That you have a perfect hypothesis and still arrive at the wrong answer
Which error type is more serious and why?
Type 1
What does changing the alpha do in a test?
Makes type 1 smaller while increasing type 2
What is the alpha value?
Criterion for how unlikely the result must be to reject null