Illustrates how expected mean squares needed in the analysis of variance can be arrived at via the use of only one rule: the expected mean square E(MS) for any source of variation for any ANOVA model is specified effect plus the specified effect in combination with any random effect. (Editor/RK)

A monetary gratuity's effect on the return rate (RR) of a mail survey was studied. Half of the surveys mailed to 507 librarians in Arizona included a 1.00 dollar gratuity. The RR was 80% among those receiving the gratuity and 59% among controls. A survey's RR and consequent validity may be improved by including a gratuity. (SLD)

Monetary incentive research has consistently shown that such influences often markedly increase returns in mailed questionnaires. In two separate studies, class-of-mail had no significant effect on return rate of mailed questionnaires. Return rates increased markedly (almost doubled) when a $1.00 gratuity was included in the first-class mailing.…

Formulas are provided for estimating statistical power of a test of significance for the difference among means under a variety of conditions. A table for quick power estimates that require no computation for comparing two means in analysis of variance and analysis of covariance is included. (TJH)

The F-distribution approximation suggested by Dixon was investigated at various combinations of alpha and degrees of freedom. Tabled values were compared with values computed utilizing the suggested formula. (Author/GSK)

Formulas are derived for computing the chi-square statistic from proportions or percentages, both for tests of goodness of fit and association. Advantages of the new formulas are given, as are some examples. (Author/MH)

A metanalysis involving 62 studies compared the response rate to mailed surveys with and without a monetary gratuity. The average response rate increased 19% when a gratuity was enclosed. Other findings that substantiate that the external validity of surveys can be increased by gratuities are discussed. (SLD)