A student who expects to improve prose must apply our analysis 
cautiously.  Even when our counts correlate with good grades, further 
research needs to define precisely how the correlation occurs.  For example, 
we found that grades go up when students spell correctly and use few 
abstract words; but one cannot exchange a word for another as mechanically 
as one can alter spelling.  Perhaps students should read more if they expect 
to use words effectively.  Then possibly they can meaningfully raise average 
word length from the low mean (4.3) to the high limit of 5.0.  Sentence 
length, word length, and readability measure scribal fluency.   Classes need 
to improve these rather than practice with those discrete grammatical and 
stylistic elements which do not correlate significantly with grades.