We began by attempting to find the origins of the sequence of characters commonly referred to as the Koch sequence. This was the first of many surprises as the KMR sequence was nowhere to be found in the Koch study. We kept looking and with guidance from Taylor we found it. KMR originated in an article written in 1919 and published in 1928 by Otto Lipmann in Berlin, Germany. The importance of Lipmann’s work was identifying a method of screening for aptitude. According to Taylor, individuals vary greatly in their ability to learn the code. Many do not possess the necessary aptitude. Of the men entering schools of radiotelegraphy, 30 to 60 percent fail to become proficient operators (see DIFFERENCES IN STUDENT PERFORMANCE).
Lipmann was the first to suggest the progress of students over a period of months could be predicted on the basis of the speed with which they initially learned a particular number of characters. To 71 subjects, he gave a certain amount of practice in learning five characters. According to Lipmann, the exam consisted of giving the examinee a changing and obscure sequence under experimental circumstances. Five Morse signs were presented acoustically with increasing difficulty, whereupon each time the examinee was asked to write down the corresponding letters.
The five characters used were: K M R S U. The rest of the KMR sequence was not mentioned in the Lipmann article.
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