R

R a sometimes confusingly polyfunctional abbreviation. To wit: 1 Response, as in the common shorthand S-R for stimulus-response. 2 Stimulus from the German word Reiz. The confusion once produced by these two conflicting uses is less these days as the latter use is now rare. 3 multiple *correlation coefficient 4 a general reasoning factor hypothesized by some to be a primary mental ability

R_c An infrequent abbreviation for conditioned response; CR is more common.

R_G In Hull's theory, any goal-attaining response, e.g. eating, drinking.

R_1,2,3,...nmultiple correlation coefficient

RP The probability of a response. This abbreviation is used little, p being the more common notation for probability, with the response under consideration usually being clear from context.

Ru An infrequent abbreviation for unconditioned response.; UR and UCR are encountered more often.

r 1 The product-moment *correlation coefficient: see also Rxy. 2 In Hull's theory, the efferent reaction leading to an overt response. Also called a pure-stimulus *act.

rbis The biserial *correlation coefficient.

rG In Hull's theory, a fractional antedating goal response.

r12.34 partial *correlation coefficient. It denotes the correlation of the variables to the left of the point (here, 1 and 2) after the influences of those to the right (here, 3 and 4) have been removed.

r2 The square of the value of a product-moment *correlation coefficient. It provides an estimate of the proportion of the variance in the data that can be attributed to the relationship. Occasionally written r-squared.

rt The tetrachoric correlation coefficient. Also denoted as rtet.

rtet Rt.

rxy The product-moment *correlation with the variables (x and y) that enter into its computation denoted.

race A term born in anthropological innocence and meant simply to designate the major subdivisions of Homo sapiens. A race was defined as any relatively large division of persons that could be distinguished from others on the basis of inherited physical characteristics such as skin pigmentation, blood groups, hair textures and the like. In actual practice, it is nearly impossible to classify or distinguish individual persons by such physical characteristics, for no specific set of them truly constitutes criterial features. If the concept has any residual meaning in this respect, it is only when the relative frequency of occurrence of physical traits in a population is assessed. For example, there are many blacks with 'lighter skins' than many 'whites', so skin color can not serve as a definitive criterion for any arbitrarily selected individual. However, among the population of persons who identify themselves as 'black' there will be a higher relative frequency of dark-skinned individuals than among the population of those who identify themselves as 'white'. Since the key criterion here is identify themselves as, it is clear that the working definition of race is one that is dependent on a social-cultural-political identification and not one that can be unambiguously determined by genetic classification. See also race differences.