eval chapter 7

the result is unlikely to be a chance occurrence

When a researcher states that a result is significant, this means that

type II error

If the researcher fails to reject the null hypothesis when there really is a difference, this is an example of a

effect size

A measure of meaningfulness that expresses the difference between the experimental and control group in standard deviation units is the

a statistical hypothesis that assumes that there is no difference among the effects of treatments

A null hypothesis is

effect size

A researcher decides to use an alpha of .01 and a power of .80. To determine the needed sample size the researcher must ascertain the expected

statistically significant but does not have a high degree of meaningfulness

If a researcher finds a small difference in average test scores between a large sample (over 700) of experimental participants and a large sample (same size) of control participants, it is very likely that the difference is

type I error

When a researcher claims that there is a difference between treatments (i.e., rejects the null hypothesis) when there really is no difference, what type of error is this?

type I error

When an experimenter states that the level of significance is the .05 level, he is setting the probability of committing which type of error?

There is no difference between the vocabulary scores of average- and high-ability students

Which hypothesis is stated in the null form?