Malignant hepatic tumours 289

43 adenomatous polyposis on chromosome 5. N a t u r e 1987; 328:614-616. 44 tyrosinemia with hepatoma. A c t a Paediatrica Scandinavica 1969; 58:393-396. 45 hepatocellular carcinoma. Childhood hepatic malignancies. Cancer 1987; 60:414-418.

Bodmer, W.F., Bailey, C.J., Bodmer, J. et al. Localisation of the gene for familial

Gentz, J., Heinrich, J., Lindblad, B. et al. Enzymatic studies in a case of hereditary

de Potter, C.R., Robberecht, E., Laureys, G. et al. Hepatitis B related childhood

Book review

Statistical Analysis for the Behavioural Sciences. 1. Cohen. New Jersey: Lawrence Erlbaum, 1989, pp. 567, E44.95.

This book is primarily a reference quide to the different methods of power calculation. The power of a statistical test is the probability that it will give statistically significant results. It depends on three quantities: the significance criterion, the reliability of the sample results and the size of the effect.

The book would be useful for anyone involved in designing studies to ensure that they use a sufficient sample size in order to draw valid conclusions. It would be particularly suitable, as the title suggests, for the social scientist since the calculations are explained at length in words rather than in pages of Greek lettering.

Each chapter deals with a different method of statistical analysis: the t test for means; the significance of a product moment correlation; differences between correlation coefficients; the test that a proportion is 0.5 and the sign test; differences between proportions; chi-squared tests for goodness of fit and contingency tables; the analysis of variance and covariance; multiple regression and correlation analysis; and set correlation and multivariate methods.

The calculations are easily solved by locating the appropriate chapter and referring to the given sample size and power tables.

KATHRYN WATERS