It was 1962, the setting of the iconic 1973 movie American Graffiti, from which comes the subtitle of this post. The Beatles had released Love Me Do, their first single. That year also heard and saw Telstar, the eerie but joyful Claviolined Joe Meek instrumental by the Tornados, celebrating the circling communications private transatlantic television satellite it honoured. The British Ford Cortina, named after an Italian ski-resort saw out the humpty-dumpty rounded Prefects and 50’s Zephyrs, while in the US, the first of 50 beautiful, mysterious and largely lost Chrysler Ghia Turbine cars was driven in Detroit.
Meanwhile, the world of statistics was not to be outdone. Rainald Bauer’s Median Quartile test, an extension of Brown and Mood’s early 50’s Median Test, was published, in German, in 1962. The latter test, still available in statistics packages such as IBM SPSS, SAS and Stata simply compares groups on counts below and above the overall median, providing in the case of two groups, a two by two table.
The Median Quartile Test (MQT), as the name suggests, compares each group on the four quartiles. But the MQT is largely unknown, mainly discussed in books and papers published in, or translated from, German.
The MQT conveys similar information to John Tukey’s boxplot, shows both analysts and their customers and colleagues where the data tend to fall, and provides a test of statistical significance to boot. Does one group show a preponderance of scores in the lower and upper quartiles for example, suggesting in the field of pharma fr’instance, that one group either gets much better or much worse.
A 1967 NASA English translation of the original 1962 Bauer paper is available in the Downloadables section of this site.
Recent Application in Journal of Cell Biology
Further / Future reading
Bauer RK (1962) Der “Median-Quartile Test”… Metrika, 5, 1-16.
Von Eye A et al (1996) The median quartiles test revisited. Studia Psychologica, 38, 79-84.
Synergistic Statistical Consulting, Analysis, Arboronics 