International Standardized Nomenclature for Outbred Stocks of Laboratory Animals.

In accordance with the «Aims of ICLA» (ICLA Bulletin No. 26, March 1970) the Governing Board established in 1969 a Working Party to prepare an International Nomenclature System for Outbred Animals. The members were: Professor, Dr.

The "completely randomised" and the "randomised block" are the only experimental designs suitable for widespread use in pre-clinical research.

Too many pre-clinical experiments are giving results which cannot be reproduced. This may be because the experiments are incorrectly designed. In "Completely randomized" (CR) and "Randomised block" (RB) experimental designs, both the assignment of treatments to experimental subjects and the order in which the experiment is done, are randomly determined.

On determining sample size in experiments involving laboratory animals.

Scientists using laboratory animals are under increasing pressure to justify their sample sizes using a "power analysis". In this paper I review the three methods currently used to determine sample size: "tradition" or "common sense", the "resource equation" and the "power analysis". I explain how, using the "KISS" approach, scientists can make a provisional choice of sample size using any method, and then easily estimate the effect size likely to be detectable according to a power analysis.

Genetically Defined Strains in Drug Development and Toxicity Testing.

There is growing concern about the poor quality and lack of repeatability of many pre-clinical experiments involving laboratory animals. According to one estimate as much as $28 billion is wasted annually in the USA alone in such studies. A decade ago the FDA's "Critical path" white paper noted that "The traditional tools used to assess product safety-animal toxicology and outcomes from human studies-have changed little over many decades and have largely not benefited from recent gains in scientific knowledge.

Randomized block experimental designs can increase the power and reproducibility of laboratory animal experiments.

Randomized block experimental designs have been widely used in agricultural and industrial research for many decades. Usually they are more powerful, have higher external validity, are less subject to bias, and produce more reproducible results than the completely randomized designs typically used in research involving laboratory animals. Reproducibility can be further increased by using time as a blocking factor.