Hi to all.
For those readers who never saw or heard a lecture or read an article by the late Len Scrivener, I write the following:

/* Let us take for example where the written word can easily be misapplied. In the Feather Step rise and fall is given thus: Rise e/o 1. Up for 2 and 3. Lower e/o 3. This is not an accurate description of the rise and fall of a skilled exponent. Peak rise is reached as the second step is completed and the follow through of the body causes the third step to be carried forward, with the foot making an ever decreasing angle to the floor. Contact with the heel is made at the end of the step. To be more accurate, therefore, the technique should read: Rise e/o 1. Up for 2. Commence lowering e/o 2. Down e/o 3. No doubt this description can be just as easily misinterpreted, but the fact remains that the effort of many dancers to maintain the rise through the second and third steps (as indicated by the technique) and at the same time move forward in character with the dance is quite unnatural. Fluency of progression is hindered and the following swing step (LF forward) is materially impeded. Experienced dancers will do as I have described, but naturally they will not make an effort to commence lowering e/o 2. It simply occurs through the laws of dynamics. However, technique states ‘up' when in actual fact the dancer is lowering.*/

Len also said that there can be no exactitude in the dance technique.