To the Editor.
—I certainly agree with Dr Manning's observations in the June Archives (1982;142:1192) that the Serial Sevens Test is a conventional part of a mental state examination, that it is not done as a timed test, and that physicians do not know how to interpret the results. Indeed, the test is one of those "CERTAIN THINGS PHYSICIANS DO" without really knowing why. Perhaps this is because they are taught by physicians who do not really know why they teach it. However, I disagree with Dr Manning's conclusion that "since the test is easily performed, it does provide a crude measure of level of intellectual function" (although he states that we should not rely too much on it).The test does not address intellectual function. Its putative use is to assess attention span and ability to concentrate. There is serious question as to its validity. Smith found that only