TY - CHAP
TI - Graphical Models: Overview
AU - Wermuth, N.
AU - Cox, D. R.
T2 - International Encyclopedia of the Social & Behavioral Sciences
A2 - Smelser, Neil J.
A2 - Baltes, Paul B.
AB - Graphical Markov models provide a method of representing possibly complicated multivariate dependencies in such a way that the general qualitative features can be understood, that statistical independencies are highlighted, and that some properties can be derived directly. Variables are represented by the nodes of a graph. Pairs of nodes may be joined by an edge. Edges are directed if one variable is a response to the other variable considered as explanatory, but are undirected if the variables are on an equal footing. Absence of an edge typically implies statistical independence, conditional, or marginal depending on the kind of graph. The need for a number of types of graph arises because it is helpful to represent a number of different kinds of dependence structures. Of special importance are chain graphs in which variables are arranged in a sequence or chain of blocks, the variables in any one block being on an equal footing, some being possibly joint responses to variables in the past and some being jointly explanatory to variables in the future of the block considered. Some main properties of such systems are outlined, and recent research results are sketched. Suggestions for further reading are given. As an illustrative example, some analysis of data on the treatment of chronic pain is presented.
CY - Oxford
DA - 2001/01/01/
PY - 2001
DP - ScienceDirect
SP - 6379
EP - 6386
LA - en
PB - Pergamon
SN - 978-0-08-043076-8
ST - Graphical Models
UR - http://www.sciencedirect.com/science/article/pii/B008043076700440X
Y2 - 2019/11/22/19:12:23
KW - Bayesianism
KW - Classical ML
KW - Machine learning
ER -
TY - CHAP
TI - Commutative Semantics for Probabilistic Programming
AU - Staton, Sam
T2 - Programming Languages and Systems
A2 - Yang, Hongseok
AB - We show that a measure-based denotational semantics for probabilistic programming is commutative. The idea underlying probabilistic programming languages (Anglican, Church, Hakaru, ...) is that programs express statistical models as a combination of prior distributions and likelihood of observations. The product of prior and likelihood is an unnormalized posterior distribution, and the inference problem is to ﬁnd the normalizing constant. One common semantic perspective is thus that a probabilistic program is understood as an unnormalized posterior measure, in the sense of measure theory, and the normalizing constant is the measure of the entire semantic domain.
CY - Berlin, Heidelberg
DA - 2017///
PY - 2017
DP - Crossref
VL - 10201
SP - 855
EP - 879
LA - en
PB - Springer Berlin Heidelberg
SN - 978-3-662-54433-4 978-3-662-54434-1
UR - http://link.springer.com/10.1007/978-3-662-54434-1_32
Y2 - 2019/11/23/16:35:50
KW - Bayesianism
KW - Probabilistic programming
KW - Programming language theory
KW - Semantics
ER -