used frequently in problem or policy-oriented studies where the researcher is not interested in testing the statistical significance of the findings
researchers have no clear idea what they may find
they have no prior info to use for predictions
search for data indications rather than to attempt to find causality
gather preliminary data
asks, "Do we have firm evidence that such-and-such is happening (or has happened)?"
only different from research questions in that it
predicts an outcome
null hypothesis (hypothesis of no difference)
asserts that the statistical differences or relationships discovered in an analysis are due to chance or random error
logical alternative to research hypothesis
probability level (significance level)
a predetermined value against which the null hypothesis is tested
if the results of the study indicate a probability level lower than this level, the researcher can _____ the null hypothesis.
fail to reject (accept)
if the research outcome has a high probability, the researcher must _____ the null hypothesis.
predicts that the results will fall in only one direction (either positive or negative)
used when researchers have knowledge of the area and are able to more accurately predict the outcome of the study
does not predict a direction
used when little info is available about the research area
there is no difference in value between a study that finds _______________ results and a study that does not.
Type I error (Alpha)
the rejection of a null hypothesis that should be accepted
under direct control of researcher
Type II error (Beta)
the acceptance of a null hypothesis that should be rejected
no direct control
provides an estimate of the minimum number of respondents needed to provide the best chance to discover if something does or does not exist.
indicates the probability that a stat test of a null hypothesis will conclude that the phenomenon under study actually exists
the degree to which the null hypothesis is rejected
can be stated either generally or exactly
the larger, the greater the degree to which the phenomenon is present
measures the effects size
research methods exam 3 chapter 11