Chapter 7 Flashcards
The six steps of hypothesis testing
- identify the populations, comparison distribution, and assumptions. 2. state the null and research hypotheses. 3. determine the characteristics of the comparison distribution. 4. determine the critical values, or cutoffs. 5. Calculate the test statistic 6. Make a decision`
critical value
a test statistic value beyond which we reject the null hypothesis; often called a cutoff
critical region
the area in the tails of the comparison distribution in which the null hypothesis can be rejected.
alpha level
the probability used to determine the critical values, or cutoffs, in hypothesis testing is an alpha level aka a p level.
the P value
is the probability of finding this particular test statistic, or one even larger, if the null hypothesis is true - that is, if there is no difference between means.
one-tailed test
is a hypothesis test in which the research hypothesis is directional, positing either a mean decrease or a mean increase in the dependent variable, but not both, as a result of the independent variable.
What is a percentile?
the percentage of scores that fall below a certain point in the distribution.
How do we calculate the percentage of scores below a particular positive z score?
We add the percentage between the mean and the positive z score to 50%, which is the percentage of scores below the mean (50% of scores are on each side of the mean}.
What is the difference between parametric and nonparametric tests?
Parametric tests are statistical analyses based on a set of assumptions about the population. By contrast, nonparametric tests are statistical analyses that are not based on assumptions about the population.
Statistically significant
We have rejected the null hypothesis because the pattern in the data differed from what we would expect by chance.
What is the difference between a one tailed hypothesis test and a two-tailed hypothesis test in terms of critical regions?
For a one tailed test, the critical region (usually 5%, or an alpha level of 0.05} is placed in only one tail of the distribution; for a two-tailed test, the critical region must be split in half and shared between both tails (usually 2.5%, or 0.025, in each tail.
what is phacking
When researchers use questionable statistical methods to increase their chances of finding a statistically significant result, for example repeatedly analyzing data and then stopping once they reach significance, or excluding extreme data points.
