Statistics Test 3

If other factors are held constant, what is the effect of increasing the sample variance?

It will increase the estimated standard error and decrease the likelihood of rejecting H0.

Which of the following is a fundamental difference between the t statistic and a z-score?

The t statistic uses the sample variance in place of the population variance.

What value is estimated with a confidence interval using the t statistic?

The value for an unknown population mean

For which of the following situations would a repeated-measures design have the maximum advantage over an independent-measures design?

When very few subjects are available and individual differences are large

The estimated standard error, s(M1-M2) in the t-test for independent samples ....

is computed based on the variances, s2 of both samples

In a repeated-measures experiment, each individual participates in one treatment condition and then moves on to a second treatment condition. One of the major concerns in this type of study is that participation in the first treatment may influence the participant's score in the second treatment. What is this problem is called?

order-effect

APA Style

t(df)= value of t, p level, r^2 Ex: t(11)= 3.73, p<.05, r^2=0.42

On average, what value is expected for the t statistic when the null hypothesis is true?

t= 0

What is the average value expected for the independent-measures t statistic if the null hypothesis is true (i.e., the two samples represent the same population)?

t=0

The t-test for independent sample can be used to examine...?

-the mean difference between two treatment conditions in an experiment (e.g. a difference in performance of experimental group and control group). -the mean difference between two populations in quasi-experimental designs (e.g., mean difference in attitudes to abortion between residents of the southern vs. northern states in the U.S.).

Which of the following is the correct null hypothesis for an independent samples t-test (assume 2-tails test)?

.There is no difference between populations represented by two samples (i.e., μ1 - μ2 = 0 or μ1 = μ2).

What is indicated by a large variance for a sample of difference scores (i.e., a large variance of D scores)?

An inconsistent treatment effect and a low likelihood of a significant difference.

For which of the following situations would a repeated-measures research design be appropriate?

B.Comparing patients' pain tolerance at the beginning and at the end of physical therapy sessions.

Which of the following research situations would be most likely to use a between-subjects research design?

Examining gender differences in analytical problem solving skills among undergraduate students.

In a two-tailed test, the null hypothesis is the same

If M= 42 then it still =42

One tailed test

In a one- tailed test, if the outcome for .05 or .01 then you reject the t-score

When n is small (less than 30), how does the shape of the t distribution compare to the normal distribution?

It is flatter and more spread out than the normal distribution.

If other factors are held constant, what is the effect of increasing the sample size?

It will decrease the estimated standard error and increase the likelihood of rejecting H0