A lurking variable is a variable that is unknown and not controlled for; It has an important, significant effect on the variables of interest. In other words, the variables will cause your results to be biased. In addition, any correlation or regression analysis you perform will be misleading.

A lurking variable is a variable that is not measured in the study. It is a third variable that is neither the explanatory nor the response variable, but it affects your interpretation of the relationship between the explanatory and response variables.

lurk, skulk, slink, sneak mean to behave so as to escape attention. lurk implies a lying in wait in a place of concealment and often suggests an evil intent.

Lurking variable. A variable that is neither the explanatory variable nor the response variable but has a relationship (e.g. may be correlated) with the response and the explanatory variable. It is not considered in the study but could influence the relationship between the variables in the study.

A lurking variable is a variable that has an important effect on the relationship among the variables in the study, but is not one of the explanatory variables studied. Two variables are confounded when their effects on a response variable cannot be distinguished from each other.

Another way to identify potential lurking variables is through examining residual plots. If there is a trend (either linear or non-linear) in the residuals, this could mean that a lurking variable not included in the study is impacting the variables within the study in some way.

Definition: Common Response occurs when changes in both x and y are caused by lurking variable z, an unlisted variable that may be influential in the statistical values of the relationship.

Lurking Variable. A lurking variable is an explanatory variable that was not considered in a study, but that affects the value of the response variable in the study. in addition, lurking variables are typically related to explanatory variables considered in the study.

Confounding variable. an extraneous variable whose presence affects the variables being studied so that the results you get do not reflect the actual relationship between the variables under investigation.

Confounding in a study occurs when the effects of two or more explanatory variables are not separated. A relation that appears to exist between a certain explanatory variable and the response variable may be due to some other variable or variables not accounted for in the study.

Extraneous variables are those that produce an association between two variables that are not causally related. Confounding variables are similar to extraneous variables, the difference being that they are affecting two variables that are not spuriously related. …

A confounding variable is an extraneous variable that obscures the true relation between two other variables or groups of interest. It hinders the ability to infer a causal relation between the variables and can lead to misattributing a causal effect to the independent variable (a threat to internal validity).

Confounding variables are any other variable that also has an effect on your dependent variable. They are like extra independent variables that are having a hidden effect on your dependent variables. Confounding variables can cause two major problems: Increase variance.