Abuses and misuses of statistics are frequent. This digest attempts to warn against these in three broad classes of pitfalls: sources of bias, errors of methodology, and misinterpretation of results. Sources of bias are conditions or circumstances that affect the external validity of statistical results. In order for a researcher to make…

The findings of nine studies comparing the symbolic play of middle-class and lower-class children are summarized and examined in detail. Related research problems are discussed and directions for future research are indicated. Examination of the studies indicated that few general conclusions can be drawn from them about the relative quality of…