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