skip navigation


Register for Latest Research

Stay Informed
Register with NCJRS to receive NCJRS's biweekly e-newsletter JUSTINFO and additional periodic emails from NCJRS and the NCJRS federal sponsors that highlight the latest research published or sponsored by the Office of Justice Programs.

NCJRS Abstract

The document referenced below is part of the NCJRS Virtual Library collection. To conduct further searches of the collection, visit the Virtual Library. See the Obtain Documents page for direction on how to access resources online, via mail, through interlibrary loans, or in a local library.


NCJ Number: 91864 Find in a Library
Title: PRIORS - An Interactive Computer Program for Formulating and Updating Prior Distributions
Author(s): J VandeVate
Corporate Author: Massachusetts Institute of Technology
Operations Research Ctr
United States of America
Date Published: 1982
Page Count: 35
Sponsoring Agency: Massachusetts Institute of Technology
Cambridge, MA 02139
National Institute of Justice (NIJ)
Washington, DC 20531
National Institute of Justice/
Rockville, MD 20849
NCJRS Photocopy Services
Rockville, MD 20849-6000
US Dept of Justice NIJ Pub
Washington, DC 20531
Grant Number: 80-IJ-CX-0048
Publication Number: OR 116-82
Sale Source: National Institute of Justice/
NCJRS paper reproduction
Box 6000, Dept F
Rockville, MD 20849
United States of America

NCJRS Photocopy Services
Box 6000
Rockville, MD 20849-6000
United States of America
Document: PDF
Language: English
Country: United States of America
Annotation: This report applies PRIORS, an interactive PL/I program, to hypothesis testing, parameter estimation, posterior distributions and updating, plots of cumulative distributions, and modifying distributions.
Abstract: After defining the why and the what of prior distribution, hypothesis testing is portrayed in the formulation of requirements for admission to a public assistance program based on applicants' assets. The problem resolved is the determination of a decision threshold that will eliminate applicants whose assets exceed the threshold value. It is shown how the interactive program OPT2 assists evaluators in formulating decision rules for hypothesis tests involving Gaussian (normal) distributions. Since many of the processes studied by evaluators can be accurately represented by underlying probability distributions and described by the parameters characterizing these distributions, the report discusses the common distributions addressed by PRIORS, their conjugate prior distributions, and how to use PRIORS to assess them. Consideration is given to the Bernoulli process, the Poisson process, the Uniform process, the normal process with independent samples, and normal regression. It is advised that the prior distributions formulated with PRIORS readily allow the addition of improved information. This process of adding information to a prior distribution is called 'updating,' and the resulting updated distribution is a 'posterior distribution.' This process is described. Additional features of PRIORS analyzed are plots of cumulative distributions and modifying distributions. The appendix describes the mathematical equations for the various distributions discussed.
Index Term(s): Computer software; Data analysis; Evaluation techniques
Note: Working Paper
To cite this abstract, use the following link:

*A link to the full-text document is provided whenever possible. For documents not available online, a link to the publisher's website is provided. Tell us how you use the NCJRS Library and Abstracts Database - send us your feedback.