Wikia

Psychology Wiki

Decision rule

Talk0
34,117pages on
this wiki

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Statistics: Scientific method · Research methods · Experimental design · Undergraduate statistics courses · Statistical tests · Game theory · Decision theory


In decision theory, a decision rule is a function which maps an observation to an appropriate action. Decision rules play an important role in the theory of statistics and economics, and are closely related to the concept of a strategy in game theory.

In order to evaluate the usefulness of a decision rule, it is necessary to have a loss function detailing the outcome of each action under different states.

Formal definition Edit

Given an observable random variable X over the probability space  \scriptstyle (\mathcal{X},\Sigma, P_\theta), determined by a parameter θ ∈ Θ, and a set A of possible actions, a (deterministic) decision rule is a function δ : \scriptstyle\mathcal{X}→ A.

Examples of decision rules Edit

  • An estimator is a decision rule used for estimating a parameter. In this case the set of actions is the parameter space, and a loss function details the cost of the discrepancy between the true value of the parameter and the estimated value.
  • Out of sample prediction in regression and classification models.

See also Edit

This page uses Creative Commons Licensed content from Wikipedia (view authors).

Around Wikia's network

Random Wiki