Hidden variable

Hidden variables may refer to:

• Hidden variable theories, in physics, the proposition that statistical models of physical systems (such as Quantum Mechanics) are inherently incomplete, and that the apparent randomness of a system depends not on collapsing wave functions, but rather due to unseen or unmeasurable (and thus "hidden") variables. In sharp contrast to the generally accepted Copenhagen Interpretation.
• Latent variables, in statistics, variables that are inferred from other observed variables
• Hidden transformation, in computer science, a way to transform a generic constraint satisfaction problem into a binary one by introducing new hidden variables
• Confounding or hidden variables in general. That is, a variable that actually creates the illusion of a causal relation (e.g. firemen often appear after smoke, not because smoke causes firemen, but because fire causes both smoke and firemen)