but it was never published Dutton did not disclose the rules he used to formulate Speedwords. So there are several apparent anomalies and obscurities. Also, Dutton appears to make arbitrary decisions on the choice of a Speedword. For example, on page 25 Dutton states that 'ao' means 'away' although 'ax' would be logical. However, 'ax' has already been used to mean 'ask'. This shows that over 50 years Dutton had not reached 100% perfection of his system. This is consistent with the effort required to be expended to fully complete as shown by the Pareto Principle. Also, on TYDS, page 25 Dutton used the Speedword 'dy' for since but gives the rationale French 'depuis' but it does not contain 'y' and in French could also translate to 'for' which already has the Speedword 'f'. Some guidelines stated in Teach Yourself Dutton Speedwords book are difficult to apply. For example, Dutton allows the reader to use synonyms for the basic Speedwords and distinguishes them from the basic speedwords by capitalising their first letter. Also, for example, English 'at' becomes the Speedword 'A' because Speedword 'a' means 'to' (TYDS, page72). Dutton says the reader can create her or his own supplementary list but does not detail how this is done or how she or he manages it. None of these disadvantages prevent its successful use for personal note taking. Achievements of Dutton Dutton Speedwords continues to be used to despite its orphan status because of his useful qualities: Dutton kept the vocabulary compact. This was achieved by using frequency of use as the criterion. Dutton provided a proven learning approach which makes it easy to master. He emphasised incremental learning with repetition. Dutton persevered with it over a long period. During the period 1933–1970 (until his death) it was refined with his personal experience and feedback from adopters and students. Evolution of speedwords It appears that Speedwords developed in five main stages: As a competitor to Pitman and Gregg shorthand. Based on the available Dutton shorthand publications held in libraries this occurred 1919–1925. At this point, it was a geometric shorthand method that competed with Pitman and Gregg shorthand methods and did not use the English alphabet. Under the influence of Horn's frequently used words list, an early attempt was made to develop an alternate international abbreviated language. Dutton expressed this in his one-page sheet called International 2-letter correspondence symbols (published 1933).