One-sample median tests
Simple and effective with an a priori hypothesis
When it comes to running statistics on one sample, an a priori hypothesis is a necessity for making proper inferences. Many survey instruments lack fundamental psychometric evidence to back up the constructs and/or items it is intended to measure. When a Likert-scale type response set or an ordinal outcome is to be assessed statistically in one sample, the one-sample median test is used.
In order to run the test, researchers must specify where along the ordinal continuum that they hypothesize that the population mean exists. The one-sample median test then compares the observed median to the hypothesized median and the p-value is interpreted.
Due to limited precision, accuracy, and variability in ordinal outcomes, it behooves researchers to use either 5-point, 7-point, or higher level Likert scales. With more options, more unique variance can be accounted for the in the analysis and statistical power is increased. One-sampled tests possess more statistical power than other between-subjects statistics because there is only one group being analyzed, no other independent groups are included.
In order to run the test, researchers must specify where along the ordinal continuum that they hypothesize that the population mean exists. The one-sample median test then compares the observed median to the hypothesized median and the p-value is interpreted.
Due to limited precision, accuracy, and variability in ordinal outcomes, it behooves researchers to use either 5-point, 7-point, or higher level Likert scales. With more options, more unique variance can be accounted for the in the analysis and statistical power is increased. One-sampled tests possess more statistical power than other between-subjects statistics because there is only one group being analyzed, no other independent groups are included.
