---
title: "BLOG: Probabilistic Models with Unknown Objects"
authors:
  - "Brian Milch"
  - "Bhaskara Marthi"
  - "Stuart J. Russell"
  - "David A. Sontag"
  - "Daniel L. Ong"
  - "Andrey Kolobov"
doi: ""
url: "https://ijcai.org/proceedings/2005/203"
pdf: "https://ijcai.org/proceedings/2005/0203.pdf"
venue: "Proceedings of the Nineteenth International Joint Conference on Artificial Intelligence"
year: 2005
pages: "1352-1358"
track: ""
keywords:
---

# BLOG: Probabilistic Models with Unknown Objects

Brian Milch, Bhaskara Marthi, Stuart J. Russell, David A. Sontag, Daniel L. Ong, Andrey Kolobov

*Proceedings of the Nineteenth International Joint Conference on Artificial Intelligence*, pages 1352-1358.

## Abstract

This paper introduces and illustrates BLOG, a formal language for defining probability models over worlds with unknown objects and identity uncertainty. BLOG unifies and extends several existing approaches. Subject to certain acyclicity constraints, every BLOG model specifies a unique probability distribution over first-order model structures that can contain varying and unbounded numbers of objects. Furthermore, complete inference algorithms exist for a large fragment of the language. We also introduce a probabilistic form of Skolemization for handling evidence.