Lurking factors

A slightly different type of masquerade takes place when a single, unknown factor influences two outputs, and one of the outputs is mistaken as a factor. G. E. P. Box has given such masquerading factors the more dramatic names of either latent variables or lurking variables [Box, Hunter, and Hunter (1978), and Joiner (1981)]. 

Based on this information, the researcher would probably conclude that the concentration of sodium ion does have an effect on the rate of the enzyme catalyzed reaction. However, this conclusion might be wrong because of the lurking presence of a highly correlated, masquerading factor, time (see Section 1.2). 

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