so resist tractable solution by any algorithm in the large size limit. During the same period, statistical pattern recognition became dominant, most notably via simple Hidden Markov Models outperforming symbolic approaches such as Hearsay-II in the domain of speech recognition. Recent developments Blackboard-like systems have been constructed within modern Bayesian machine learning settings, using agents to add and remove Bayesian network nodes. In these 'Bayesian Blackboard' systems, the heuristics can acquire more rigorous probabilistic meanings as proposal and acceptances in Metropolis Hastings sampling though the space of possible structures. Conversely, using these mappings, existing Metropolis-Hastings samplers over structural spaces may now thus be viewed as forms of blackboard systems even when not named as such by the authors. Such samplers are commonly found in musical transcription algorithms for example. Blackboard systems have also been used to build large-scale intelligent systems for the annotation of media content, automating parts of traditional social science research. In this domain, the problem of integrating various AI algorithms into a single intelligent system arises spontaneously, with blackboards providing a way for a collection of distributed, modular natural language processing algorithms to each annotate the data in a central space, without needing to coordinate their behavior. Blackboard systems represent a promising solution for very difficult diagnosis problems solving. Intelligent Medical Hybrid System is a blackboard system proposed to offer a solution for cooperative diagnosis problems-solving by human specialists and intelligent knowledge source agents. See also Artificial intelligence systems integration Autonomous decentralized systems Opportunistic reasoning Pandemonium architecture Tuple spaces References External links Open Blackboard System An open source framework for developing blackboard systems. GBBopen An open source blackboard system framework for Common Lisp. Blackboard Event Processor An open source blackboard implementation that runs on the JVM but supports plan scripting in JavaScript and JRuby. KOGMO-RTDB A real-time open source blackboard for C/C++, used by some DARPA Urban Challenge autonomous vehicles. HarTech Technologies A company that provides both Simulation and Command and Control solutions which are all based on a unique Blackboard architecture. The Blackboard development framework can be utilized to develop custom applications. The BB1 Blackboard Control architecture An older Blackboard system, available for Common Lisp and C++. Macsy A modular blackboard architecture for Python built on top of MongoDB for the annotation of media content. Further reading Retrieve PDF Article Architectural pattern (computer science) Artificial intelligence