independent variable


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variable

 [var´e-ah-b'l]
something that changes; an attribute or property of a person, event, or object that is known to vary in a given study.
dependent variable in a mathematical equation or relationship between two or more variables, a variable whose value depends on those of others; it represents a response, behavior, or outcome that the researcher wishes to predict or explain.
extraneous variable a factor that is not itself under study but affects the measurement of the study variables or the examination of their relationships.
independent variable in a mathematical equation or relationship between two or more variables, any variable whose value determines that of others; it represents the treatment or experimental variable that is manipulated by the researcher to create an effect on the dependent variable.

in·de·pen·dent var·i·a·ble

a characteristic being measured or observed that is hypothesized 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.

independent variable

(in research) a variable that is manipulated (controlled) by the researcher and evaluated by its measurable effect on the dependent variable or variables. For example, in a study of the effect of nursing intervention on postoperative vomiting, nursing intervention is the independent variable evaluated by its effect on the dependent variable, the incidence of postoperative vomiting. Also called experimental variable, predictor variable. Compare dependent variable.

in·de·pen·dent var·i·a·ble

(in'dĕ-pen'dĕnt var'ē-ă-bĕl)
statistics A variable that is manipulated by the researcher and measured by the effect it has on the dependent variable or variables.

in·de·pen·dent var·i·a·ble

(in'dĕ-pen'dĕnt var'ē-ă-bĕl)
Characteristic being measured or observed that is hypothesized to influence another event or manifestation within a defined area of relationships under study.

variable

1. any type of measurement, quantitative or qualitative, of which a series of individual observations is made so that it has, as a principal characteristic, the potential for variability.
2. has the quality of variability.

variable agent
an agent in the cause of a disease which is capable of variation in intensity, e.g. weather, as contrasted to one that is not variable, e.g. Salmonella dublin.
concomitant v's
in experimental design these refer to factors that affect the dependent variable, but are not themselves influenced by the treatment (e.g. age of animal). The effect of concomitant variables can be removed by suitable experimental design or by including them in the model.
continuous variable
one in which all values within a given range are possible, e.g. birth weights of calves.
variable costs
costs which vary with the dimensions of the activity. Includes seed, fertilizer, teat dip, worm drench. Called also direct costs. See also fixed costs.
dependent variable
1. in statistics the variable predicted by a regression equation.
2. a variable which depends on other variables for its value.
discontinuous variable
see discrete variable (below).
discrete variable
one in which the possible values are not on a continuous scale, e.g. the number of sheep in a flock.
endogenous variable
dependent variable.
exogenous variable
independent or predetermined variable.
independent variable
one not dependent on other variables but capable of affecting dependent variables, thus an input variable.
spatial variable
a measurement relating to area or location.
temporal variable
one relating to chronological time.
References in periodicals archive ?
To document experimental control, the independent variable in single-subject research is actively, rather than passively, manipulated.
withdrawal design), treatment is implemented followed by a return to baseline through the removal of the independent variable.
i] represent a value on the dependent variable for case i, and the values of k independent variables for this same case be represented as [x.
Using the same methodology described above, but replacing the dependent variable, net outlays, with net cost of operations, once again the most suitable independent variable is the POM (w/OCO) position.
Among the various available statistics Cox and Snell R2 and Nagelkerke are mostly used to asses the goodness-of-fit of the model with all of the independent variables and told us magnitude of the explained variation.
However, the path coefficients for H5, H6, H7, H8 and H9 affirmed that all four independent variables have direct effect on the level of job satisfaction in this model too.
Regression is a method of statistical analysis through which, by the assignation of determined values to a dependent variable y and to one or more independent variables [x.
First, the correlation relationship between the dependent variable and independent variables are tested and then regression method is used to determine the mathematical relationship between dependent and independent variables.
Additionally the Coefficient table shows the sig value of the independent variables individually.
The elementary premises of normal squares method are dependent variable normality, conon-linearity among independent variables and stationarity of dependent and independent variables.
The Normality Assumption Test, The Homoscedasticity Assumption Test, The Linearity Assumption Test of each of the Independent Variables with the Dependent Variable, The Durbin-Watson d Statistic Test for Detecting Serial Correlation and The Multicollinearity Test, in trying to understand the significant and the insignificant variables.
Figure 2 provides one example of this type of test trial in which information is used to evaluate control of behavior by the relation between the independent variables and the name of the Independent Variable 1 (REL & IV1).

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