Test 2- Chapter 8 Notes
the level of significance or criterion for a hypothesis test
alpha
A state meant that directly contradicts a null hypothesis by stating that the actual value of a population parameter is less than, greater then or not equal to the value stated in the null hypothesis
alternative hypothesis
type II error is symbolized by
beta
what can you decrease to increase power
beta error, population standard deviation and standard error
A method for testing a claim or hypothesis about a parameter in a population, using data measured in a sample
hypothesis testing
what can you do to increase power
increase effect size, sample size and alpha
to increase power you should ___ effect size, ____ size and _____; decrease ____, _____ and _____
increase; sample; alpha; beta; population standard deviation; standard error
if d is above .8 then effect size is
large
a criterion of judgment upon which a decision is made regarding the value stated in a null hypothesis
level of significance
the p value of a sample outcome is compared to the _____
level of significance
if d is between .2 and .8 then effect size is
medium
when a null hypothesis is retained, a result is
not significant
a statement about a population parameter, such as the population mean, that is assumed to be true
null hypothesis
sample means obtained beyond the critical value will result in a decision to reject the ____
null hypothesis
in hypothesis testing, an effect is insignificant when we retain the ____; an effect is significant when we ___ the null hypothesis
null hypothesis; reject
the ____ is compared to the critical values of a hypothesis test to make a decision
obtained value
the value of a test statistic
obtained value
hypothesis tests where the alternative hypothesis is stated as greater than or less than a value stated in the null hypothesis
one tailed tests
a statistical procedure used to test hypotheses concerning the mean in a single population with known variance
one- independent sample z test
the probability of obtaining a sample outcome, given that the value stated in the null hypothesis is true
p value
the __ in hypothesis testing is the probability of rejecting a false null hypothesis
power
the probability that a randomly selected sample will show that the null hypothesis is false when the null hypothesis is indeed false
power
when the obtained value exceeds a critical value, we decided to ___ the null hypothesis
reject
the region beyond a critical value in a hypothesis test
rejection region
when the value of a test statistic is in the ___ we decide to reject the null hypothesis
rejection region
when a null hypothesis is rejected a result is ____
significant
if d is less than .2 than effect size is
small
the level of significance criterion is based on the probability of obtaining a ___ measured in a sample of the value stated in the null hypothesis were ___
statistic; true
a decision made concerning a value stated in the null hypothesis
statistical significance
a mathematical formula that allows researchers to determine the likelihood of obtaining sample outcomes if the null hypothesis were true
test statistic
the value of the ___ is used to make a decision regarding the null hypothesis
test statistic
hypothesis tests where the alternative hypothesis is stated as not equal to
two tailed tests
the probability of rejecting a null hypothesis that is actually true
type I error
the probability of retaining a null hypothesis that is actually false
type II error
occurs with one tailed test, where the researcher decides to retain the null hypothesis because the rejection region was located in the wrong tail
type III error
an inferential statistic used to determine the number of standard deviations in a standard normal distribution that a sample mean deviates from the population mean stated in the null hypothesis
z statistic
what are the four steps of hypothesis testing
1. state the hypothesis 2. set the criteria for a decision 3. compute the test statistic 4. make a decision
a measure of effect size in terms of the number of standard deviations that mean scores shifted above or below the population mean stated by the null hypothesis
Cohen's D
standard rules for identifying small, medium and large effects based on typical findings in behavioral research
Cohen's effect size conventions
Researchers directly control for the probability of committing ___ error
Type I
a cutoff value that defines the boundaries beyond which less than 5% of sample means can be obtained if the null hypothesis is true
critical value
the difference between a sample mean and the population mean stated in the null hypothesis
effect
the larger the value of D the large the ___
effect in the population
a statistical measure of the size of an effect in a population
effect size
