Think about differences between group means in terms of
standard deviations, not standard errors of the mean. Mean ± SD or Mean ± SEM?
Learn exactly what a trivial, small, moderate, large, very
large, and almost perfect effect is, for a correlation, a
frequency difference, and the effect-size statistic. Magnitudes for Effect Statistics
Present as few numbers as possible: no more than two
significant digits for effect statistics and standard
deviations. How Many Digits?