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Show using a standard denominator such as 1,000 or 100,000 persons. regression analysis Regression analysis is a tool used by economists and others to estimate the relationships among a dependent variable Y and one (or many) independent variable(s) X. The purpose of regression analysis the "best fit" data points from a straight line down on an XY graph. relative risk The rate of disease in one group exposed to a particular factor (e.g., a toxic spill) divided by the rate in another group which is not exposed. A relative risk of one (1) indicates that the two groups have the same rate of disease. risk or risk factor Risk is a term used by epidemiologists to quantify the likelihood that something will occur. A risk factor is something which either increases or decreases an individual's risk of developing a disease. However, it does not mean that, if exposed, an individual will definitely contract a particular disease. standard error In statistics, the standard error is defined as the standard deviation of an estimate. That is, multiple measurements of a given value will generally group around the mean (or average) value in a normal distribution. The shape of this distribution is known, as the standard error. survey An investigation in which information is systematically collected. A population survey may be conducted by face-to-face inquiry, by self-completed questionnaires, by telephone, by postal service, or in some other way. Each method has its advantages and disadvantages. The generalizability of results depends upon the extent to which those surveyed are representative of the entire population. type I error Also known as "false positive" or "alpha error." An incorrect judgment or conclusion that occurs when an association is found between variables where, in fact no association exists. In an experiment, for example if the experimental procedure does not really have any effect, chance or random error may cause the researcher to conclude that the experimental procedure did have an effect. type II error Also known as "false negative" or "beta error." An incorrect judgement or conclusion that occurs when no association is found between variables where in fact, an association does exist. In a medical screening, for example, a negative test result may occur by chance in a subject who possesses the attribute for which the test is conducted. 144 |