Definition: Model exceedance probability
Index:
The Book of Statistical Proofs ▷
Model Selection ▷
Bayesian model selection ▷
Random-effects Bayesian model selection ▷
Exceedance probabilities
Sources:
Metadata: ID: D238 | shortcut: excprob | author: JoramSoch | date: 2026-06-29, 17:53.
Definition: Let $p(y,m,r)$ with data sets $y = \left\lbrace y_1, \ldots, y_N \right\rbrace$, generative models $m \in \left\lbrace 0, 1 \right\rbrace^{N \times K}$ and model frequencies $r \in [0, 1]^K$ be the joint likelihood function of the model specified by random-effects Bayesian model selection and let $p(r \vert y)$ be the posterior distribution resulting from estimation of this model.
Then, the posterior exceedance probability of the $j$-th model frequency $r_j$, i.e. the probability that, given the data, the $j$-th model is more frequent than any other model, is called the exceedance probability of model $j$:
\[\label{eq:excprob} \mathrm{EP}_j = \varphi_{p(r|y)}(r_j) = \mathrm{Pr}\left( \forall i \in \left\lbrace 1, \ldots, n | i \neq j \right\rbrace: \, r_j > r_i \, \vert \, y \right) \; .\]- Stephan KE, Penny WD, Daunizeau J, Moran RJ, Friston KJ (2009): "Bayesian model selection for group studies"; in: NeuroImage, vol. 46, pp. 1004–1017, eq. 16; URL: https://www.sciencedirect.com/science/article/abs/pii/S1053811909002638; DOI: 10.1016/j.neuroimage.2009.03.025.
- Soch J, Allefeld C, Haynes JD (2016): "How to avoid mismodelling in GLM-based fMRI data analysis: cross-validated Bayesian model selection"; in: NeuroImage, vol. 141, pp. 469-489, p. 474; URL: https://www.sciencedirect.com/science/article/pii/S1053811916303615; DOI: 10.1016/j.neuroimage.2016.07.047.
Metadata: ID: D238 | shortcut: excprob | author: JoramSoch | date: 2026-06-29, 17:53.