| continuous variable | A variable that may take on any value in an interval or intervals (its domain). (05 Mar 2000) |
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| sample, random | A group selected randomly, solely by chance. (12 Dec 1998) |
| pure random drift | That which has random components only with an average value of zero and no systematic effects. Brownian movement in a still container shows pure random drift but in the Mississippi shows a steady downstream tendency. (05 Mar 2000) |
| dependent variable | In experiments, a variable that is influenced by or dependent upon changes in the independent variable; e.g., the amount of a written passage retained (dependent variable) as a function of the different numbers of minutes (independent variable) allowed to study the passage. (05 Mar 2000) |
| immunoglobulin variable region | That region of the immunoglobulin (antibody) molecule that varies in its amino acid sequence and composition, confers the antigenic specificity, and is thought to comprise the binding site for the antigen. It is located at the n-terminus of the fab fragment of the immunoglobulin. It includes hypervariable and framework regions, vh family subgroups, and the complementarity-determining region. (12 Dec 1998) |
| independent variable | A characteristic being measured or observed that is hypothesised to influence another event or manifestation (the dependent variable) within a defined area of relationships under study; that is, the independent variable is not influenced by the event or manifestation, but may cause it or contribute to its variation. See: dependent variable. (05 Mar 2000) |
| intermediate variable | A variable in a causal pathway that causes variation in the dependent variable and is itself caused to vary by the independent variable. (05 Mar 2000) |
| intervening variable | An event, such as an attitude or emotion, inferred to occur within an organism between the stimulation and response in such a way as to influence or determine the response. (05 Mar 2000) |
| ordered on-random off mechanism | A scheme for substrate binding and product release for multisubstrate enzymes; for a two-substrate two-product enzyme with this mechanism, the individuals have to bind to the enzyme in a distinct order; however, once the products are formed they may dissociate from the enzyme in either order. It has been suggested that pyruvate kinase has such a mechanism. The random on-ordered off mechanism is simply the reverse of this mechanism. (05 Mar 2000) |