New Generation Computing, 12 (1993) 1-5 OHMSHA, LTD. and Springer-Verlag

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Knowledge Science

Setsuo Ohsuga Research Center for Advanced Science and Technology The University of Tokyo 4-6-1 Komaba Meguro-ku, Tokyo 153 Japan

w Introduction A research project titled "Research on Concept Formation and Knowledge

Acquisition in Knowledge Science" referred to simply as 'knowledge science' is being conducted under the sponsorship of the Ministry of Education, Culture and Informa- tion. Its major objectives are to establish a research field on the various phenomena of knowledge accounting for different points of view and to provide for research on intellectual activities such as concept formation and knowledge acquisition in human beings and computers. This project introduces the term "knowledge science" for the first time. This field actually overlaps in many areas with knowledge engineering. The latter term, however, is often thought to be biased towards application-oriented technol- ogy, and our objective is focused on basic research. This research covers observation of human activity in concept formation and knowledge acquisition, analysis of informa- tion gathered for various purposes and attempts to mimic human activity by computers. It covers a very wide scope of phenomena on knowledge.

w The Goals of Research Artificial intelligence, especially knowledge processing technology will play an

important role as key technology in our computerized society. There are, however, a number of problems that must be solved before this technology can occupy a cental position in information processing. The most serious problems are (1) clarifying the process of concept formation so that knowledge can be formed and accumulated from outside, (2) integrating it with technology so that the knowledge can be used and (3) automating the process. The importance of resolving these problems is undoubtedly obvious to the people involved in the study of artificial intelligence. We do not therefore need to describe the purpose of this research project in any other terms. What is being attempted in this research project is to accept diverse information from the real world, to formulate concepts based on this information, to convert these concepts into an internal form, and to save them in the memory as knowledge to be used for the realistic problem solving.

In order to attain these goals, we need to develop techniques for complex information processing. For the purpose of automating such a process, it is necessary to analyse the functions involved in concept formation and knowledge acquisition. This project involves the following subgoals, (1) processing verbal and non-verbal informa- tion semantically at the imput stage, (2) clarifying the process of building a concept

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based on meanings and developing its algorithms, (3) theorizing this process, (4) solving problems related to computerization including the database and knowledge base technology, (5) linking these techniques to those using knowledge and (6) to integrating these technologies into a system. The major objective is to investigate the various aspects involved in acquiring knowledge and to form a basis for a method to research this field.

w Outline of Research Project This project is divided into the following five subfields in order to create a

foundation of knowledge acquisition and resolve these problems and implement systems applicable to the real world. Different research groups are assigned to each subfield. Each group is further divided into subgroups to resolve more specific research problems. A-group: Theorizing the process of concept formation and knowledge acquisition,

headed by Professor S. Arikawa of Kyushu University. B-group: Concept formation and knowledge acquisition from language and pattern

information, headed by Professor G. Hatano of Dokkyo University. C-group: Functions and computer algorithms for concept formation and knowledge

acquisition, headed by Professor M. Shimura of Tokyo Institute of Technol- ogy.

D-group: Knowledge acquisition from databases, headed by Professor S. Nishio of Osaka University.

E-group: Knowledge acquisition in Computer Assisted Instruction, headed by Profes- sor S. Ohtsuki of Kyushu Institute of Technology.

3 .1 Theorizing the Process of Concept Formation and Knowledge Acquisition Research of concept formation and knowledge acquisition must take into

account many points of view. In order to integrate these views, it is necessary to establish a theoretical foundation for these activities. The major objective for this group is to formalize the activities and develop a theory which can be used by the other groups as a common base. This group is divided into three subgroups. The A-1 subgroup reseaches the logic behind concept formation and knowledge acquisition. They view the logic of knowledge from the viewpoint of learning and systemizes that logic into a model. They analyse and systemize various forms of reasoning attained by human beings as well as formalized reasoning such as common knowledge reasoning, hypothesis reasoning, analogical reasoning and inductive reason- ing. Formalized reasoning has already been researched in the field of artificial intelli- gence. This subgroup intends to develop a logic which form basis for all of these. The A-2 subgroup studies concept formation and knowledge acquisition based on formalized inference. They plan to use common knowledge reasoning as an inference for acquiring knowledge. They will consider such logic as default reasoning, non- monotonic reasoning, self-reference and hypothesis reasoning from the viewpoint of logic as the means of reasoning for knowledge acquisition. They will try to make these forms more efficient. The A-3 subgroup researches the amount of computations necessary for concept formation and knowledge acquisition. Using the formal language model as a target of research, they will develop a foundation of learning and knowledge acquisition and then attempt to design a theory for knowledge acquisition. They are also studying

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learnability.

3 .2 Concept Formation and Knowledge Acquisition from Language and Pattern Information In order for knowledge processing systems to attain concept formation and

knowledge acquisition, it is necessary to study these functions in human beings. This cooperative group of cognitive scientists and information scientists studies concept formation and knowledge acquisition from the viewpoint of language and pattern information. This group is divided into four subgroups. The B-1 subgroup studies concept formation and knowledge acquisition from the aspect of language information. Assuming that a ready set of language information is given as input, they attempt to implement a software system. The B-2 subgroup studies concept formation and knowledge acquisition from the view of non-language (pattern) information. They study a way of forming concepts and acquiring knowledge based on visual information. They intend to research semantic aspects of pattern information. The B-3 subgroup studies the integration of language and pattern information. They investigate the interaction between language and pattern information in concept forma- tion and knowledge acquisition. They plan to develop a software system to implement their ideas. The B-4 subgroup studies concept formation and knowledge acquisition for language. They investigate the learnability process involved in acquiring knowledge from the external world. They try to clarify the constraints existing between the external and internal worlds. They also study the inference mechanism in the internal world.

3 . 3 Functions and Computer Algorithms for Concept Formation and Knowledge Acquisition Knowledge acquisition is becoming a bottle neck for realistic knowledge

processing technology. This group researches how to develop a conceptual model and high-level learning capability in practical knowledge processing systems establishing formalized knowledge as a target. This group is divided into three subgroups. The C-1 subgroup researches concept formation and learning processes. They investi- gate the way human beings make conceptual models and acquire knowledge. They also study the knowledge accumulation processes in relation with the study of short-term and long-term memories. The C-2 subgroup researches leaning processes. Taking the human process of knowl- edge acquisition into account, they consider ways that allow machines to learn. Based on this research they attempt to establish a learning method and implement it in computers. The C-3 subgroup focuses on a high-level learning system. They study ways to acquire knowledge that humans are incapable of. They intend to develop knowledge acquisi- tion tool, learning systems, and a system which can acquire an efficient problem solving capability by learning.

3 .4 Knowledge Acquisition from Databases Databases are considered to be the complement of knowledge bases in forming

a global information source. These technologies, however, have not yet been effectively combined. This research group concentrates on how can knowledge be acquired from

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a large amount of data in databases. This group is composed of four subgroups. The D-1 subgroup studies ways to make knowledge base for multimedia information. They first try to establish knowledge representations for multimedia information including pictures, diagrams and sounds. They intend to combine the logical approach and the object-oriented approach. On the basis of these knowledge representations, they are going to build a knowledge base model. The D-2 subgroup studies ways of giving flexibility to databases. They intend to build a flexible database scheme which enables the accumulation of multimedia information that maintains interrelationships between data. The D-3 subgroup researches knowledge acquisition from databases. They pursue a method and mechanism that can be used for automatically extracting knowledge or general rules out of a large amount of data accumulated in databases under the control of meta-knowledge. The D-4 subgroup studies ways to make inference efficient in combining knowledge bases and databases. They view multimedia data and knowledge as research objects in which an efficient inference algorithm is pursured.

3 .5 Knowledge Acquisition in Computer Assisted Instruction Computer Assisted Instruction (CAI) is the most useful application field in the

research of concept formation and knowledge acquisition. It is important for applica- tion as well as a source of basic ideas on concept formation and knowledge acquisition because, as the objective of CAI is to support human learning, learning in human students and machines both must be taken into consideration. This research group studies concept formation and knowledge acquisition in CA1. This group is composed of three subgroups. The E-1 subgroup studies concept formation and knowledge acquisition from the viewpoint of teaching and understanding. They analyse human learning as a cognitive process and cosider teaching strategies that can be used to lead learners to efficient understanding by making use of these results they experiment through teaching and learning. The E-2 subgroup researches concept formation and knowledge acquisition based on a learner' s model. They intend to make an individual learner' s model by constructing a knowledge base which is specific to each learner and represents the learner' s state of understanding and its time variations. They intend to clarify the difference among effects in concept formation and knowledge acquisition according to a learner' s personalities and the difference among states of understandings. The E-3 subgroup studies ways to identify reasons for mistakes that occur during leaning and knowledge acquisition. They intend to device an identification method based on inductive and hypothesis reasoning. They also intend to extend this method to other learning theories including explanaiton-based learning and machine invention.

w Summary An outline of research project titled ++Research on Concept Formation and

Knowledge Acquisition in Knowledge Science" abbreviated as +Knowledge Science' being conducted under the sponsorship of the Ministry of Education, Culture and Information has been presented. This project was scheduled for three years beginning in 1991 and is approaching to the final stage. Research activity is still continuing and is producing significant results, some of which have been published regularly in the

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form of interim reports and in proceedings of open symposiums. The final report will be made available next year.

Acknowledgements This project is supported by a grant from the Ministry of Education, Culture and

Information. As a representative of this research project, the author wishes to express sincere thanks to all those who supported, organized and participated in this endeavor.

References 1) Ohsuga, S. (ed.), Research on

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Concept Formation and Knowledge Acquisition in Knowledge Science Research Report (1991), Area No. 215, Ministry of Education, Culture and Information, 1992. Ohsuga, S. (ed.), Proceedings of Symposium on Concept Formation and Knowledge Acquisition in Knowledge Science, 1992. Ohsuga, S. (ed.), Research on Concept Formation and Knowledge Acquisition in Knowledge Science, Research Report (1992), Area No. 215, Ministry of Education, Culture and Information, 1993.