Provider: ingentaconnect
Database: ingentaconnect
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TY - ABST
AU - Fitts, Douglas A
TI - Minimizing Animal Numbers: The Variable-Criteria Sequential Stopping Rule
JO - Comparative Medicine
PY - 2011-06-15T00:00:00///
VL - 61
IS - 3
SP - 206
EP - 218
N2 - The variable-criteria sequential stopping rule (SSR) allows an investigator to use a few subjects at a time to determine whether a planned experiment is worth pursuing without increasing the rate of false discoveries (type I errors). The SSR is appropriate whenever testing a null hypothesis
if the experiment can be conducted in stages. The investigator adds a predetermined number of subjects at each stage and tests repeatedly for significance until the experiment is stopped because: (1) a significant effect is detected; (2) the effect is clearly not going to be significant; or
(3) the predetermined maximal number of subjects has been reached. Two crucial features of the SSR are that it holds the probability of a type I error constant and maintains excellent power. The method is more efficient than is performing a typical significance test after a power analysis
because SSR can require 30% fewer subjects to achieve the same power. The variable-criteria SSR provides a formal method for assuring the use of a minimal number of animals. This article provides practical examples of how to use the SSR in combination with a *t* test, one-way ANOVA, one-way
ANOVA with a planned contrast as the focus of the stopping rule, or, in limited circumstances, multifactorial ANOVA.
UR - http://www.ingentaconnect.com/content/aalas/cm/2011/00000061/00000003/art00004
ER -