From Knowledge Engineering to Ontological Engineering -- A New Trend in Knowledge Model Building for ITSs -- Riichiro Mizoguchi ISIR, Osaka University

Agenda  Two technologies in AI –Formal: Inference/reasoning, Learning, DM, etc. –Content: Model-building, knowledge modeling  Two Content technologies –Knowledge engineering –Ontological engineering  An example(OMNIBUS/SMARTIES)

Form-oriented approach  Inference –Deductive inference: Normal procedure –Inductive inference: Learner modeling –Constraint approach: Learner modeling  Machine learning –Learner modeling –Data mining  Semantic Web approach –Metadata, Annotation, DL

Content-oriented approach  Domain analyses  Knowledge modeling  Knowledge base building –Rule base technology Production rules –Expert systems  Knowledge engineering

Two wheels of AI Formal technology Content technology

From Knowledge Eng. To Ontological Eng. KE is the research on –Domain-specific heuristics for a stand-alone problem solver OE is the research on –General/reusable/sharable/long-lasting concepts for building a KB/model for helping people solve problems

Ontology as a system of concepts Used as conceptual building blocks of knowledge-intensive systems such as ITSs –Something deeper than metadata –It provides foundation on which a KB or an application system is built Ontology Knowledge Base (Model) An explicit specification of a hidden conceptualization of the target domain

Dichotomy of ontology Light-weight Ontology –One like Yahoo ontology –Vocabulary rather than concepts –Annotation-oriented ontology –Used for Information search Heavy-weight Ontology –One I discuss –Concepts rather than vocabulary –for understanding the target world –for building ontology-aware system

The fundamental role of an ontology An ontology is not directly used for problem solving It gives a specification of knowledge/models in a system The role of an ontology to a knowledge base is to give definitions of concepts used in the knowledge representation and constraints among concepts –to make the knowledge base consistent and transparent which are the necessary properties of sharable and reusable knowledge These are the heart of IA (Intelligence Amplifier) systems. –From AI to IA

An example  OMNIBUS –An ontology of learning and instructional theories –A kind of heavy-weight ontology  SMARTIES –A rule-less expert system which can help users build theory-compliant learning/instructional scenarios

Nine policies for building a good ontology  Policy 1 –Model roles appropriately because the world is full of roles. Use Hozo for that purpose.  Policy 2 –All but events which are dynamic things such as actions should be modeled in terms of state change.  Policy 3 –Events should be defined in terms of processes which are used as material. An event is a unitary thing which must be viewed as a whole. Actions should be primitive and play roles specified in events which provides contexts.  Policy 4 –Introduce the idea of “ Engineering approximation ” to model theories ．  Policy 5 –Identify a maximal conceptual unit necessary and sufficient for modeling all the phenomena of insterest.

Nine policies for building a good ontology(Cont’d)  Policy 6 –When representing a procedure, decompose it into What to achieve and How to achieve. Organize both separately. The former is “ purified action ” and the latter “ way (to achieve) ”.  Policy 7 –Build an action-decomposition tree by repeating action decomposition using the conceptual unit obtained by Policy 5 and purified actions & Ways obtained by Policy 6.  Policy 8 –Build a Way knowledge base as an ontology by analyzing procedural knowledge sources to extract and organize ways.  Policy 9 –Build a mechanism to perform action-decomposition by retrieving applicable ways from the Way base. It can be viewed as a kind of inference engine.

How SMARTIES works

Scenario model in SMARTIES (1/4) Abstract Concrete LO Learning content Scenario (sequence) Scenario description The goal of the learner in this scenario is to be in "Apply level" state Step1 The instructor "Shows familiar things". The learner "Looks at it". This interaction is for making the learner be in "Have recognized" state. [...more] Step2 The instructor "Shows familiar things in an unfamiliar manner". The learner "Looks at it". This interaction is for making the learner be in "Have recognized" state. [...more] … Scenario description The goal of the learner in this scenario is to be in "Apply level" state Step1 The instructor "Shows familiar things". The learner "Looks at it". This interaction is for making the learner be in "Have recognized" state. [...more] Step2 The instructor "Shows familiar things in an unfamiliar manner". The learner "Looks at it". This interaction is for making the learner be in "Have recognized" state. [...more] … Goal of the scenario

Scenario model in SMARTIES (2/4) Goal of the scenario Abstract Concrete WAY Decomposition and Achievement relation between macro and micro I_L events WAY Decomposition and Achievement relation between macro and micro I_L events I_L event Interaction between an instructor and a learner. State-change of the learner I_L event Interaction between an instructor and a learner. State-change of the learner

Scenario model in SMARTIES (3/4) Abstract Concrete I_L event Interaction between an instructor and a learner. State-change of the learner I_L event Interaction between an instructor and a learner. State-change of the learner WAY Decomposition and Achievement relation between macro and micro I_L events WAY Decomposition and Achievement relation between macro and micro I_L events Way Theory A WAY-knowledge is a WAY defined based on a theory A theory is modeled as a set of WAY- knowledge All the necessary concepts for defining WAYs are defined Way Theory A WAY-knowledge is a WAY defined based on a theory A theory is modeled as a set of WAY- knowledge All the necessary concepts for defining WAYs are defined

Ontological engineering is interesting Scenario interpreter OMNIBUS ontology Scenario model Explanation generator Model manager WAY-K manager Explanation of the scenario Guidelines based on theories Scenario making Explanation template IMS LD output module IMS LD output WAY- knowledge (WAY-K) IMS LD Scenario author (e.g. Teacher, Instructional designers, etc.) IMS LD compliant tools Scenario editor Ontology author Knowledge author (e.g. theorists) Learning objects WAY-K editor IEEE LOM OMNIBUS ontology WAY- knowledge (WAY-K) Hozo Installed SMARTIES Maintenance Block diagram of SMARTIES Thank you!

Core model of learning/instructional events The difficulty in modeling instruction and learning might be that the change is achieved by two kinds of actions: –Instructional actions leads a learner to do some sort of learning actions –Learning actions cause the change of learner’s state. The key points of our conceptualization are –to emphasize the relation among the three and –to model a contribution of instructional action on the change of learner’s state. I_L event Advance the development / Develop / Developed Learning action State-change (Terminal state) Instructional action Instructional event Learning event Instructional theory Learning theory

Examples of decomposition To weld –What to achieve = To join sheets of metals –How to achieve = By fusion way To glue –What to achieve = To join two things –How to achieve = By glue way Put them together Put them together Melt Fusion way To join Cool Put them together Put them together Glue Glue way Dry

Selecting alternative strategies from different theories Support learning / Aquire understanding / Understand Arrange learning / Prepare / Prepared -> Developed Advance the development / Develop / Developed Assess the learning outcome / --- / Assessed Assure sustainability / Sustain / Sustaining the learning Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Preparing Learning condition Coached exercise Simple event Feedback event Developmental event ref. Dick and Carey Arrange learning / Prepare / Prepared -> Developed Advance the development / Develop / Developed Assess the learning outcome / --- / Assessed Assure sustainability / Sustain / Sustaining the learning Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Preparing Learning condition Coached exercise Simple event Feedback event ref. Dick and Carey Present what to learn / Recognize / Recognizing what to learn Give guidelines / Recognize / Recognizing how to learn ref. Gagne and Briggs Present an example of the desired performance / Recognize / Recognizing the content ref. Collins or Way-knowledge base Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed Advance the development / Develop / Developed Present content / Recognize / Recognizing the content Guide practice / Develop / Developed