title: Epidemiology for nutritionists: 2. Sampling.
abstract: There are two major objectives in sampling for a research study. The first is the avoidance of bias due to selection: to achieve this a random sample must be drawn and a high response rate achieved. The second objective is to achieve an efficient use of resources by selecting a sample of a size sufficient to detect an effect of clinical importance yet not so large that effects too small to be of interest are detected. Both these aspects will be discussed here.
mesh_terms: D002648:Child; D004812:Epidemiologic Methods; D006801:Humans; D009748:Nutrition Disorders / Q000453:epidemiology*; D009747:Nutritional Physiological Phenomena; D012107:Research Design / Q000592:standards; D012494:Sampling Studies