Ch8 hypothesis testing
alternative hypothesis
a statement that directly contradicts a null hypothesis
one-tailed tests are associated with
greater power assuming the valley stated in the null hypothesis is false
directional Test/one tailed test
hypothesis test in which the alternative hypothesis is stated as < > a value stated in the null hypothesis. the researcher is interested in specific alternative to the null hypothesis
increasing sample size
increases power by reducing standard error thereby increasing the value of the test statistic in hypothesis testing
null hypothesis
it is starting a Point.we test whether the value stated in the null hypothesis is likely to be true
two-tailed test are
more conservative and then lemonade the possibility of committing a type 3 error
type 3 error
possible with only one tailed test in which a decision would have been to reject the null hypothesis but the researcher decides to retain the null hypothesis because the rejection region was located in the wrong tail
level of significance
testing criterion we used to decide whether the value stated in the null hypotheses is likely to be true
for a one tailed test
the alpha level is placed in a single tail of a distribution
as the size of an effect increases
the power to detect the effect also increases
type 1 error
the probability of rejecting a null hypothesis that is actually true researcher directly control for the probability of committing this type of error
type 2 error
the probability of retaining a null hypothesis that is actually fall
1 sample Z test
used to test hypotheses about a population mean when the population variance is known
non-directional test
used to test hypotheses when we are interested in any alternative to the null hypothesis
to increase power increase effect size sample size and alpha
you decrease betta population standard deviation and standard error
