See an interesting collection of material related to Decision Theory Group staffed by many excellent researchers trained in medical decision making.
Hemant Bhargava maintains an interesting collection of information on decision-support systems, many of which relate to Bayesian networks and influence diagrams.
Here is the complete set of responses to Ira's request for information:
Date: Thu, 23 Feb 95 13:42:04 EST From: firstname.lastname@example.org (Ira Haimowitz) To: uai@maillist.CS.ORST.EDU Subject: Responses: Learning belief nets (long). Sender: owner-uai@maillist.CS.ORST.EDU Precedence: bulk Thanks to all who answered my query about learning Bayesian Belief nets!!! The response was wonderful. Below I post the original query and all replies with actual systems and contacts. The message is fairly long. -- Ira Haimowitz, GE Corp. Research & Development. ----------------------------- *** Original query ************* : Dear Collaegues: : : Does anyone know of any WWW server or otherwise net-available code for : automated learning of Bayesian belief nets? Either learning the : structure from data, or learning probabilities given structure and : data would be desirable. We are researching use of these techniques; : we know of some papers, but could use pointers to available software. : : Thanks very much for any pointers. ***** Answers (In rough order of receipt) ************* ------------- From: A_J_Zawilski%mwcorp1@MWMGATE1.mitre.org To: email@example.com (Ira Haimowitz) Subject: Re: Tools for inducing belief nets You probably already know about the page that Russ Almond maintains on belief networks http://www.stat.washington.edu/belief.html you might also try the decision theory group at microsoft research http://www.research.microsoft.com/research/dtg/ again you probably know everyone there too. those are the only relevant web addresses that I know. hope the info is of some use. Tony Zawilski ------------- From: Christopher Meek
To: firstname.lastname@example.org (Ira Haimowitz) Subject: Re: Tools for inducing belief nets In-Reply-To: <9502012017.AA20919@oceana.crd.ge.com> References: <9502012017.AA20919@oceana.crd.ge.com> In regards to your querry about automated procedures I offer the following inexpensive commercial alternative and a pointer to a list of many commercial and non-commercial software packages. http://www.stat.washington.edu/belief.html The commercial package is described below. Chris Meek TETRAD II Short Description A multi-module program that assists in the construction of causal explanations for sample data and their use in prediction. With continuous variables the program will aid in the search for "path models" or "structural equation models;" with discrete data the program will construct and update a Bayes network from sample data and user knowledge of the domain; the program includes Monte Carlo facilities. Proofs of the asymptotic correctness of all but one of the search modules are available in P. Spirtes, C. Glymour and R. Scheines, Causation, Prediction and Search, Springer Lecture Notes in Statistics, 1993. Platform(s): DOS In the future a Unix version may be available. The DOS software comes with a ~250 page manual with chapters on theoretical foundations, interpreting output, and a chapter on each of the software modules. Each of the chapters include many detailed example of running Tetrad II. Authors: Richard Scheines, Peter Spirtes, Clark Glymour, and Christopher Meek (1994). TETRAD II: Tools for Discovery. Lawrence Erlbaum Associates, Hillsdale, NJ. Ordering information Phone orders : 1-800-926-6579 Mail orders : Lawrence Erlbaum Associates 365 Broadway Hillsdale, N.J. 07642 Extended description TETRAD II has 10 modules, each of which has its own chapter in the manual. They are: Build Purify Makemodel Estimate MIMbuild Monte Update Search STATwriter Tetrads Build, Purify, MIMbuild, and Search are the main inference modules. Using appropriate statistical tests, Build makes a series of decisions about independence and conditional independence relations among measured variables. This information is used to search for a class of models that cannot be distinguished by conditional independence relations alone, and that are compatible with user-entered background knowledge. Purify, MIMbuild, and Search work on normally distributed linear structural equation models with latent variables, and use substantive assumptions provided by the user together with statistical decisions about vanishing correlations and tetrad differences to estimate features of the causal structure. If the variables modeled are all discrete, then the Estimate module can calculate maximum likelihood estimates of the parameters of a Bayesian network that contains no latent variables, and the Update module can use these estimates to calculate conditional distributions. Makemodel and Monte provide a useful Monte Carlo simulation package. Makemodel takes an unparameterized causal structure and, after prompting the user for an interpretation of the structure as either a Bayesian network or a recursive linear structural equation model, parameterizes the structure and writes a fully parameterized statistical model to a TETRAD II readable file. Monte can then be used to generate samples of any size from such a model. Although TETRAD II does not estimate or test linear models, it will automatically write out input files to three popular packages that do: LISREL, EQS, and CALIS. The module takes a path diagram and covariance or raw data and will automatically write out an input file to the package Of your choice. ------------ I received your message from Neal Lovell, a former student. I have 2 suggestions for you: 1) Locate certain software by going to my "Decision Support Systems" page: http://bhargava.as.nps.navy.mil/www/hkb/research/dss.html Currrently there is a link that will be of use to you: http://www.stat.washington.edu/belief.html 2) More generally, you may want to look at our DecisionNet page: http://dnet.as.nps.navy.mil/dNethome.html In the future (as we become public and get more "providers") you may find much of use here. Further, if your organization could support this effort in some way ... we are certainly looking for sponsors. Hemant Bhargava Naval PG School ------ From: "Kevin Korb" Date: Thu, 2 Feb 1995 12:02:21 -0500 In-Reply-To: email@example.com (Ira Haimowitz) "Tools for inducing belief nets" (Feb 1, 3:17pm) References: <9502012017.AA20919@oceana.crd.ge.com> X-Mailer: Z-Mail (3.1.0 22feb94 MediaMail) To: firstname.lastname@example.org (Ira Haimowitz) Subject: Re: Tools for inducing belief nets Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 Hi Ira, I do not know of such; if you hear of any, I'd be interested. I am investigating the learning of causal structure here at Monash & would be happy to hear about your efforts/interests. I do know of Glymour, et al.'s Tetrad II; I believe it's available for around $150 (US) from Lawrence Erlbaum Associates. It is for learning causal structure from correlational data, not for learning numerical parameters. We've ordered it, but not yet received it. (It is not Bayesian learning; for background see their 1993 book in the Springer Verlag Statistics Lecture Notes series.) Whether there's code available for Herskovitz's and others' approaches, I don't know but would like to. My guess would be that Heckerman's work for Microsoft is and will remain unavailable. Whatever code we end up producing here will be made available, at least in its initial versions. Any corrections as to matters of fact would be most welcome. Regards, Kevin P.S. Perhaps you can compile responses such as mine & repost them collectively to uai? I'd be interested in seeing what others have to say. ------------------------------------------------------------------- Dr. Kevin Korb email@example.com Dept. of Computer Science phone: +61 (3) 905-5198 Monash University fax: +61 (3) 905-5146 Clayton, Victoria 3168 Australia --------- From: Stuart Russell To: haimowitz@crd.Ge.Com Subject: learning belief nets Hugin has a version called aHugin that adjusts parameters as it goes along. You can probably get the code from the same source as Hugin. (If you are working with Piero Bonissone: I mentioned to him some new methods we have for learning belief nets with hidden variables, which the Heckerman and Cooper methods cannot do. If you are interested, we could work on your data set, although we are not ready to release code yet.) Stuart Russell ------ From: David Madigan Subject: Re: Tools for inducing belief nets To: Ira Haimowitz In-Reply-To: <9502012017.AA20919@oceana.crd.ge.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Check out: http://www.stat.washington.edu/belief.html ----------- From: Eero.Hyvonen@vtt.fi (Eero Hyvonen) Subject: Re: Tools for inducing belief nets Cc: firstname.lastname@example.org Dear Ira Haimowitz, Unfortunately I cannot really help you with your question, but your concern is something we will be encountering in our research project just starting. Actually, I once implemented (ESCOM-meeting, Munich, 1992) the Lauritzen-Spiegelhalter-algorithm in Lisp with a simple learning scheme for tuning the conditional probabilities given the network, but that piece of software was done just for experimentation and learning the formalism. Until now, we have not been active on the topic. We would be greatful, if you could forward us information you may get in response to your request. It would also be nice to lear more on your own work if you have published something (our address is below). It seems that you are using some net-available code for belief nets already now (?) If so, could you make a recommendation and how to get it? Yours sincerely Eero Hyvonen ----------- From: Bo Thiesson Date: Thu, 2 Feb 1995 09:26:15 +0100 To: email@example.com Subject: Re: Tools for inducing belief nets X-Sun-Charset: US-ASCII Dear Ira Haimowitz, At the ftp site: ftp.iesd.auc.dk you can get the BIFROST program for structural learning: pub/packages/BIFROST/bifrost.1.1 (I have discovered a bug in bifrost.1.2) User's guide: pub/reports/tech-reports/R92-2001.ps.Z Theoretical report about BIFROST: pub/reports/tech-reports/R92-2010.ps.Z The program is available free of charge for non-commercial use. BIFROST presupposes another program; CoCo to be installed too. Also if you want to be able to use the exportation facility to HUGIN, HUGIN has to be installed. You can get CoCo at the same ftp site, where you will find it in pub/packages/CoCo HUGIN is a commercial product. For information, please, contact firstname.lastname@example.org -Bo Thiesson --------- From: email@example.com (Sven Vestergaard, Hugin Expert A/S) Subject: Re: Tools for inducing belief nets Dear Ira Haimowitz A feature in our old version of Hugin Professional (version 3.3) is the ability to learn. We are using the algorithms described in: David J. Spiegelhalter and Steffen L. Lauritzen. Sequentail updating of conditional probabilities on directed graphical structures. Networks, 20: 579-605, 1990. LEARNING: "A feature of Hugin (version 3.3) is the ability to learn from a set of data. Hugins learning facilities has the following features: They work on incomplete data, and they work on a running system. Thus, you can initiate Hugin with data from an existing database (which need not to be complete), and then let the running system continue to learn as new data is generated. The latter also allows a system using Hugin to adapt to a changing world, thus preventing the system to become out of date." We have just introduced our new API with a lot of new features, and are going to upgrade the Learning features .An updated version will be released April 95. (the old algoritm is not implemented in the new code) Some features of our new version of the Hugin system. (Version 4.0) Influence diagrams. An influence diagram is a belief network argumented with decisions and utilities. Arcs in the influence diagram into a random variable represents probabilistic dependencies while arcs into a decision variable represents availability of information at the time the decision is taken. Assuming a total ordering of the decisions, an optimal decision policy using maximization of expected utility for choosing between decision alternatives can be computed. The new version of the Hugin system allows specification of and inference and decision making with influence diagram. This version will also take advantage of the case where the overall utility is a sum of a set of local utilities. New propagation methods: A `max'-propagation to identify the most probable configuration of all variables and compute its probability, and a new way to incorporate evidence, known as `fast retraction', permits the computation, for each variable, of the conditional probability of that variable given evidence of the remaining variables (useful for identifying suspicious findings). Thus, four different ways of propagating evidence are now available. Graphical models with undirected edges, so-called `chain graph' models, are now permitted. This extends the class of models so that automatically generated models are more easily used with Hugin (in automatically generated models, the direction of an association is only rarely identified). The new version will allow extraction of joint probabilities on a group of variables, even when the group is not a subset of any clique. The new version of the Hugin API will allow the user to incorporate these new features into his/her own programs. In addition, the new Hugin API will allow construction and editing of belief networks and influence diagrams. Analysis of data conflicts, which have previously been available from within Hugin Runtime, is now also available via the API. A `random' propagation method to simulate configurations, given evidence, is also provided. The interface of the API has undergone a major clean-up and redesign. But older programs, using older versions of the API, will still compile with the new API via a backwards compatibility mode. *************************************************************** BAYESIAN NETWORKS, BELIEF NETWORKS,.... there is only one HUGIN A software package for construction and execution of model based expert system. Sven Vestergaard firstname.lastname@example.org Phone: +45 98156644 Hugin Expert A/S Fax: +45 98158550 Niels Jernes Vej 10 Internet: email@example.com DK - 9220 Aalborg O Mosaic: http://hugin.dk ftp: hugin.dk *************************************************************** From: "Jirousek Radim, KIZI, 2435, 413nb" Organization: University of Economics, Prague,CZ To: firstname.lastname@example.org Date: Thu, 2 Feb 1995 09:40:32 CET Subject: Bayesian net software Priority: normal X-Mailer: Pegasus Mail v3.1 (R1a) X-Charset: ASCII X-Char-Esc: 29 Dear colleague, within some international grant we are preparing some software system. If the officials in Brussels have no objection I would like to offer you soem version of it for testing (if you are interested). I believe, it may be in May. Best regards, Radim Jirousek Prague, Czech Republic ----------- From: Reimar Hofmann To: email@example.com Subject: Re: Tools for inducing belief nets Cc: Volker.Tresp@zfe.siemens.de Dear Ira Haimowitz! We are also interested in learning structure and/or parameters of Bayesian belief networks or Markov networks from data. We would therefore be happy if you could inform us about the results of your survey. We fond the paper Operations for Learning with Graphical Models [75 pages] Wray L. Buntine, RIACS \& NASA Ames Research Center FTP-host: ack.arc.nasa.gov FTP-file: /pub/buntine/lwgmja.ps.Z an useful overview. Concerning Software we have tested "Hugin". Hugin is a commercial system which allows learning parameters of Bayesian belief networks with discrete variables,and propagation of evidence. A free demo-version of hugin can be downloaded via ftp from ftp-host: hugin.dk Mosaic: http://hugin.dk Email: firstname.lastname@example.org I hope this is of any help. Thanks for any information about results Reimar Hofmann --------- Reimar Hofmann ZFE T SN 41 Siemens AG Corporate Research and Development Otto-Hahn-Ring 6 Phone: +49/89/636-46986 D-81730 Muenchen Fax: +49/89/636-3320 Germany e-mail: Reimar.Hofmann@zfe.siemens.de -------------------------------------------- From: Geoffrey Rutledge Reply-To: rutledge@CAMIS.Stanford.EDU To: email@example.com (Ira Haimowitz) Subject: Re: Tools for inducing belief nets In-Reply-To: Your message of Wed, 1 Feb 95 15:17:59 EST Ira, I do not know if it is net-available, but Eddit Herskovits (ehh@camis) and Greg Cooper (cooper@camis) have developed extensive software to accomplish this... you might inquire if they would help. Geoff Geoffrey Rutledge (firstname.lastname@example.org) ----------------------------------------------------------------- From: Greg.Cooper@smi.med.pitt.edu To: email@example.com Subject: Re: Tools for inducing belief nets I'd suggest you contact Peter Spirtes (firstname.lastname@example.org) and ask him how you obtain a copy of Tetrad II, which is commercially available. It uses non-Bayesian methods to learn the structure and parameterization of Bayesian belief networks. Greg ----------------------------------------- From: email@example.com (Kathryn Blackmond Laskey) Subject: Re: Tools for inducing belief nets A graduate student of mine acquired K2 from Eddie Herskovits. He supplies his code with no guarantees. Matt was able to puzzle it out and get it working in a different version of Pascal. Herskovits is at Noetic Systems (the company that markets Ergo). I'll get you more detailed information if you need it. Kathy Laskey George Mason University ----------------------------------------------- From: Robert Cowell You can obtain a copy of my BAIES program by anonymous ftp from my machine 188.8.131.52 in subdirectory pub/BAIES. There are two versions of the program, one for sparc and one for DOS. The relevant files are freebaies.tar.Z and pcbaies.tar.Z (Note unix compression and packing of pc version.) The file command ls does not work on my server, and neither does mget - i have not been able to set it up properly. You have to change directory and use the get command with full file name, which is a bit of a pain. So assuming you have logged in: ftp> cd pub/BAIES ftp> bin ftp> get freebaies.tar.Z ftp> get pcbaies.tar.Z ftp> bye BAIES is restricted to analysing connected dags with discrete variables. It is command line based, with options chosen using a simple menu which scrolls off the screen. Although presenting a primitive interface it does quite alot of things which you may have read about in the literature. It has both probability learning and model criticism features, though no structural search. There is also a semi-complete postcript documentation in the tar file. It is fast for small domains, but for large problems a bit slow. Some people have had problems with the pc version so the sprac version is probably better to use. For the last couple of years i have been working on a successor to BAIES, which I call Xbaies. A version is available by ftp, but this release has no probablity learning features. However it does have a friendlier windowing user interface, runs on Sparc, HP, DEC, Alphas and Windows 3.1, and has other features. It is in the top level of the ftp directory. So assuming you have just logged on: ftp> bin ftp> get alpha.tar.gz ftp> get dec.tar.gz ftp> get hp.tar.gz ftp> get sparc.tar.gz ftp> get xbaies.zip ftp> bye I have implemented probability learning for Dirichlet mixture priors in a separate program but this is not yet available. It may or may not become available. Best wishes, Robert Cowell Department of Statistical Science | Tel: +44 071 387 7050 ext 3636 University College London, | Fax: +44 071 383 4703 Gower Street, | Email: firstname.lastname@example.org LONDON WC1E 6BT, U.K. PS. If your organisation has megabucks to spare, and you like my xbaies program you might like to consider supporting my research here, which is due to come to an end in April with my grant running out. --------------------------------------------------------------------- From: email@example.com (Russell G. Almond) To: firstname.lastname@example.org Cc: uai@maillist.CS.ORST.EDU, email@example.com, firstname.lastname@example.org In-Reply-To: <9502012017.AA20919@oceana.crd.ge.com> (email@example.com) Subject: Re: Tools for inducing belief nets I would like to get a similar list of software. I'll add it to the graphical model software page (or maybe make a separate one). Here are the things I know about (First few taken from Steffan Lauritzen's short course at AI & Stats): K2 (Cooper and Herskovits) -- I don't have contact information for this one. BIFROST (Hojsgaard and Thiesson) -- Contact firstname.lastname@example.org for more details. (This may require Hugin to run, I'm not sure). CoCo (Badsberg 1992) --- This is available from: ftp://ftp.iesd.auc.dk/pub/packages/CoCo/CoCo.1.2/ You can contact the author at email@example.com Less automated solutions involve software which will fit a given model structure but not do model selection (improvement) for you. MIM (Edwards 1990) --- This is a flexible program fitting many types of grpahical models. It is not a complete data analysis environment. Runs on PCs. Available from the author: David Edwards, Bymarken 38, DK-4000 Roskilde, DENMARK I believe their is a small charge for the program. Also, there is a close correspondence between undirected graphical models and generalized linear models (GLMs). (Whittaker's book on graphical models is probably a good starting place if you are unfamiliar with GLMs and Log-linear models.) A number of mainstream statistical packages fit GLMs, e.g., S-Plus, SAS and of course GLIM. They are not free, but check around, your institution may already own a site licence. I'd be very grateful if people could help me add to/flesh out this list. I'll try and make another web page for it. BTW, I appologize for not getting updates to the belief software list. UW has not had as rapid turn-around time on this as I would like. I'm assured by my local system gurus that StatSci will have a web site "real soon now" so I'll advertise again when I get all the updates posted. [in a later message from R. Almond:] One other possibility is Graphical-Belief. Graphical-Belief is StatSci's commercial system for manipulating graphical models. Its currently a research prototype, but I'm hoping to have an alpha release ready for other researchers by the summer. Currently, Graphical-Belief contains relatively limited tools for model updating (we have some tools for updating parameter estimates based on new data, although we do get around the global independence assumption of Spiegelhalter and Lauritzen ). But I've felt for a long time, that Graphical-Belief would be the ideal environment for expirimenting with some of David Madigans ideas about Model Uncertainty. The hooks are in place for this already and I'm currently looking for funds to pursue that line of research and development. One of the reasons I mention this is because I have been talking to one of your colleagues, Mahesh Morjaria (Morjaria@crd.ge.com) about potential applications of Graphical-Belief. I've sent him a number of technical reports, some of which you may find interesting. I've CCed him on this message. Hope this answers some of your questions. If you have any more I'd be happy to answer them. Russell Almond StatSci (a division of MathSoft) 1700 Westlake Ave., N Suite 500, Seattle, WA 98109 (206) 283-8802 x234 FAX: (206) 283-6310 Email: firstname.lastname@example.org -------------------------------------------------------------------