1. A defect in structure or function. 2. In biostatistics: 1) a mistaken decision, as in hypothesis testing or classification by a discriminant function; 2) the difference between the true value and the observed value of a variate, ascribed to randomness or misreading by an observer. 3. A false or mistaken belief; in biomedical and other sciences, there are many varieties of e., for example due to bias, inaccurate measurements, or faulty instruments.
alpha e. type I e
beta e. type II e
experimental e. the total e. of measurement ascribed to the conduct of an empirical observation. It is commonly expressed as the standard deviation of replicated experiments. There may be many components, including those in the sampling procedure, the measurements, injudicious choice of a model, observer bias, etc.
e. of the first kind in a Neyman-Pearson test of a statistical hypothesis the probability of rejecting the null hypothesis when it is true.type I e;
inborn e.'s of metabolism a group of disorders, each of which involves a disorder of a single unique enzyme, genetic in origin and operating from birth; effects are ascribable to accumulation of the substrate on which the enzyme normally acts (e.g., phenylketonuria), to deficiency of the product of the enzyme (e.g., albinism), or to forcing metabolism through an auxiliary pathway (e.g., oxaluria).
interobserver e. the differences in interpretation by two or more individuals making observations of the same phenomenon.
intraobserver e. the differences in interpretation by an individual making observations of the same phenomenon at different times.
residual e. the estimated discrepancy between the actual measured datum and the value for that value computed after a model has been fitted to the set of the data by an estimator.
e. of the second kind in a Neyman-Pearson test of a statistical hypothesis, the probability of accepting the null hypothesis when it is false; the complement of the power of the test.type II e;
technical e. that component of experimental e. that is due to the conduct of the experiment and in principle estimated by replicate determinations on aliquots from the same specimen.
type I e. e. of the first kindalpha e;
type II e. e. of the second kindbeta e;
Browse Medical References: