Inferential Stats Flashcards
An inferential statistical test enables an investigator to determine the probability of obtaining a sample with a particular value by comparing the obtained sample value to an approapriate ___distribution.
sampling
When the sample value of interest is a mean the comparison distribution is the sampling distribution of the____which is the distribution of means that would be obtained if a large number of equal-sized random samples were drawn from the same___and the mean of each sample was calculated.
mean;population
While many sample means would equal the population mean because of the effects of___some means would be lower than the population mean and some would be higher.
sampling error
In inferential statistics a sampling distribution is not actually constructed by obtaining a large number of samples. Instead a theoretical sampling distribution is derived from probability theory. According to the_____Theorem, the sampling distribution of the mean is____shaped;its mean equals the____;and its standard deviation, the”_____of the mean” is equal to the population____divided by the square root of the_____.
Central Limit ; normally; population mean;standard error;standard deviation; sample size
The results of an inferential statistical test indicate whether the obtained sample value falls within the region of likely values or unlikely values in the___distribution.
sampling
When the results of the statistical test indicate that the obtained sample value falls in the region of unlikely values, the null hypothesis is___and the alternative hypothesis is___.
rejected;accepted
The size of the___region(region of unlikely values) is defined by alpha. A researcher sets alpha before collecting and/or analyzing the data.
rejection
In psychological research alpha is usually set at .01 or____. When alpha is .01 this means that___% of the sampling distribution is the region of unlikely values while the remaining___% of the region of likely values.
.05; 1;99
The region of unlikely values is always placed in one or both___of the sampling distribution so that it contains the sample values that are least likely to occur as the result of sampling error alone.
tails
When the results of a study are “statistically____” this means that the sample statistic is in the___of the sampling distribution and that the investigator has rejected the____.
significant; rejection region;null hypothesis
When a researcher makes the decision to retain or reject the ____hypothesis there is no way to know with certainty if the decision is correct or in error. There are two kindsof
null
A TypeI error is made when a true null hypothesis is____. This occurs when a researcher concludes that an independent variable has had an effect on the dependent variable but the observed effect was actually due to____. The probability of making a Type I error is equal to____. For example, when___is set at .05 and the researcher has rejected the null hypothesis there is a___% chance that a TypeI error has been made.
rejected; sampling error; alpha(level of equivalence); alpha; 5;
a Type II error is made when a false null hypothesis is__. This occurs when the researcher decides that an independent variable has no effect on thedependent variable when it actually does. A Type II error might occur when the___variable was not administered in sufficient intensity or for a long enough period of time, when the sample size was too___,or when alpha was too___.
retained; independent; small;small
A researcher can of course make a correct decision.One kind of correct decision is to___a true null hypothesis. In this situation, the researcher correctly concludes that any observed effect of an IV is actually due to_____.
retain; sampling error
The other correct decision is to___a false null hypothesis. In this situation the researcher correctly decides that the___had an effect on the DV. When a statistical test enables a researcher to make this kind of correct decision, the test is said to have power.
reject; IV
