Practical Considerations on Identity for Instance Management in Ontological Investigation

EKAW2010 12th Oct. 2010, Lisbon, Portugal Practical Considerations on Identity for Instance Management in Ontological Investigation Kouji Kozaki, Satoshi Endo, and Riichiro Mizoguchi The Institute of Scientific and Industrial Research, Osaka University Japan University, 2010/10/12 EKAW2010 1

Agenda of My Talk  Motivation  Identity of normal type(concepts which are not roles)  Kinds of identity in general  Consideration on instance identity  4 kinds of instance identities  Identity for Exactness (Numerical identity)  Identity for Essentiality  Identity for Counting  Identity for Replacement  Identity of roles  Model of roles  Identities of constituent role and post role  Concluding remarks 2010/10/12 EKAW2010 2

Motivation  The identity discussed in philosophy (numerical identity)  Any P, P(X) = P(Y)  X and Y are identical  Not very practical for talking about identities of individuals! Instance identity of normal types y yp  (1) Replacing parts of your bike It's Not my bike anymore! I’m fixing I’m fixing this bike. this bike. thi bik Instance identity of roles What bike aye you fixing ?  (2) Counting the number of guests of a restaurant  The total number of guests in a month  Special menu for frequent customer  (3) The number of parliament members …  When a member resigns, a vacancy appears. 80 480  There is no difference between all 480 vacancies. Japanese lower house 2010/10/12 EKAW2010 3

Kinds of Identity  Class identity of a thing  Identity for discussing the sameness of the class individuals belong to. Different in terms Essential property of class identity A property which determines the identity of its instances instances.  Instance identity This talk  Identity for discussing the sameness of instances as they are. Same or Not Class identity vs. Instance identity Not your Porsche any more! replace Porsche it changes its Beetle It keeps its class identity instance identity 2010/10/12 EKAW2010 4

Consideration of Instance Identity  We consider kinds of identity according to their strength. How strictly th sameness of i t H t i tl the f instances i j d d is judged (1)Strictly speaking, (2) They are the same they are different. > because the change is negligible negligible. a bolt of an instance of bike is replaced Before After with another one just counting the number of guest < counting who came how many times We discuss four kinds of identities according to their strength and features. 2010/10/12 EKAW2010 5

Identity for Exactness(Iex)  Identity which means the exact sameness.  It corresponds to numerical identity.  How rigidly Iex d dl discusses the exact sameness? h  Every instance of a physical entity changes as time goes by.  e.g. A bike rusts as time goes by and changes in terms of Iex. g g y g  e.g. An instance of person “John” at present and him five minutes ago are different in terms of Iex at the two time points. Different in terms of Iex Different in terms of Iex Iex1 Iex2 Replacement of a bolt f b lt It rusts as 5 min. ago present t1 t2 time goes by They Th are often recognized as th same in practice ft i d the i ti →It is necessary to define identities which are weaker than Iex . 2010/10/12 EKAW2010 6

Identity for Essentiality (Ies)  Identity which is defined by essential property.  e.g. essential property of John's bike is a comfortable saddle which he g p p y has used for ten years. The bike keeps Ies1 unless When the saddle (its essential property ) is the saddle has been changed. replaced with another, the Ies1 changes . Essential Ies1 Ies1 Ies2 to John Changed! t1 t2 t3 The same in termsof Ies Different in terms of Ies Notice: F N ti From an engineering viewpoint, we permit arbitrariness i i i i t it bit i to capture an essential property of a concept. 2010/10/12 EKAW2010 7

Identity for Counting (Ico)  Task of counting the number of instances  We do not consider the details of each instance discussed in terms of Iex or I Ies if following three conditions are satisfied: f ll i th diti ti fi d  (1) we can recognize whether instances are the target to count or not.  (2) we can distinguish each from others.  (3) we can avoid duplicate counting.  Identity for Counting (Ico) [synchronic identity] :  Identity hi h Id tit which argues about the number of instances satisfying b t th b fi t ti f i the above three conditions.  e.g. There are five bikes in terms of Icobike 1~5. g Icomotorbike 1 Icobike 1 Icobike 2 Icobike 3 Icobike 4 Icobike 5 Icomountain bike 1 Icomountain bike 2 2010/10/12 EKAW2010 8

A Counting as a Real-world Task  We need non-zero time to accomplish counting.  If some parts of the target instance of counting are replaced during the counting task, we would fail to count th ti t k ld f il t t them.  e.g. three bikes (A~C) , their essential properties are two wheels.  Ico can’t be used for discussing whether the bike changes its identity can t or not after its part replacement because it is synchronic identity. Different in terms of Ies The number ✓ 4 ✓? Ies1 A Ies4 Ies A’ of bikes is 4 ! ✓Ies2 ? B ? Ies2 B (✓) ? Ies2 B ✓ : being counted ✓ (✓):has been Ies3 Ies3 C Ies3 C Ies3 C counted We need another identity weaker than Ies. t1 t2 t3 2010/10/12 EKAW2010 9

Identity for Replacement(Ire)  Identity which an instance of the whole continues to be itself without becoming another thing while whose parts are being replaced independently of their kinds and number of the replaced parts. Different in terms of Ies The same in terms of Ire A ? Ies1 A Ire1✓ Ire1 Ies4 Ies4 A’ (✓) Ire1 Ies2 ✓ B Ire2 Ies2 Ire2 B B(✓) ✓ : being B ? ? ? Ies2 Ire2 counted (✓):has been Ies3 Ies3 C Ire3 Ies3 Ire3 C Ies3 Ire3 ✓ C C counted t1 t2 t3 We can count the number of three bikes correctly. 2010/10/12 EKAW2010 10

Agenda of My Talk  Motivation  Identity of normal type(concepts which are not roles)  Kinds of identity in general  Consideration on instance identity  4 kinds of instance identities  Identity for Exactness (Numerical identity)  Identity for Essentiality  Identity for Counting  Identity for Replacement  Identity of roles  Model of roles  Identities of constituent role and post role  Concluding remarks 2010/10/12 EKAW2010 11

Fundamental Scheme of Our Role Model “In a context, there are players who play role concepts and thereby become role holders”. “In a restaurant, there are persons who play guest roles and thereby become guests.” Role-Holder Context C t t Guest G e t Role Concept Player Restaurant Guest Person Class Role playable depend on Role-Holder Instance vacant role Guest-1 Restaurant A Guest John Role-1 Context depend on playing Role-playing Role playing thing Role Concept “In Restaurant A, John plays guest role-1 and thereby becomes guest-1” 2010/10/12 EKAW2010 12

Fundamental Scheme of Our Role Model “In a context, there are players who play role concepts and thereby become role holders”. “In a restaurant, there are persons who play guest roles and thereby become guests.” Role-Holder Context C t t Guest G e t Role Concept Player Restaurant Guest Identity of role-holder Person Class Role is composed by the role playable depend on concept and the player Role-Holder Instance vacant role Guest-1 Restaurant A Guest John Role-1 Context depend on playing Role-playing thing Role playing Role Concept “In Restaurant A, John plays guest role-1 and thereby becomes guest-1” 2010/10/12 EKAW2010 13

Constituent role and post role  We divide role concept into two parts:  constituent role represents the player’s participation in the context to b t become a constituent of the context. tit t f th t t  post role represents what kinds of post the player is required to fulfill. Guest role at class level Role Holder Role-Holder Context Guest Role Concept Potential Player Restaurant Guest Person Role Identity of role-holders playable depend on are determined by role y Guest role at class level G t l t l l l concepts and its players Context Guest Role-holder Guest Restaurant Potential player depend on Restaurant Restaurant Restaurant Role-holder Constituent Constituent Constituent Post Role Constituent Role Potential player depend on Guest Guest Restaurant Restaurant Post Role Post Rolel Constituent Role Constituent Role Person PPerson P playable playable 2010/10/12 Played by constituent role holder EKAW2010 14

Example: Guests of a Restaurant in the Instance Level Context Role-holder Guest Restaurant Potential player Restaurant R t t Role-holder Role holder Constituent Post Role Constituent Guest Role Potential player Restaurant Post Role Constituent Role C tit t R l Person playable playable Class Context Role-holder Instance Restaurant Guest-1 Role-holder A Restaurant A Role-holder Role holder Constituent-1 Guest-2 Restaurant A Constituent Role-1 John playing Role-holder Guest Post Role Instance of Role-playing of Restaurant A g thing Restaurant A Constituent Role Constituent-2 Instance of Post Role playing Role-playing thing Restaurant A Mary playing Constituent Role-2 Legends Role-playing Instance of playing depend on playable/playing thing Constituent Role instance-of Role-playing thing relationship between role-holder 2010/10/12 EKAW2010 and individual role-holder 15

Example: Guests of a Restaurant in the Instance Level Context Role-holder Guest Restaurant Potential player Restaurant R t t Role-holder Role holder Constituent Post Role Constituent Guest Role Potential player Restaurant Instances of constituent role Post Role (in C titcase lof the t R guests of a restaurant) Person Constituent Role playable -created at the same time playable players’ participation. of new Class -disappears when the player stops the participation. Context Role-holder Instance Restaurant Guest-1 Role-holder A Restaurant A Role-holder Role holder Constituent-1 Guest-2 Restaurant A Constituent Role-1 John playing Role-holder Guest Post Role Instance of Role-playing of Restaurant A g thing Restaurant A Constituent Role Constituent-2 Instance of Post Role playing Role-playing thing Specification Restaurant Aa player of what Mary Legends is expected to play. Role-2 Role-playing playing Constituent The Guest Post Role is shared Instance of playing depend on playable/playing thing l one post role Role each (only ( Constituent f l for h by multiple constituent roles instance-of Role-playing thing role concept in the context) relationship between role-holder 2010/10/12 EKAW2010 and individual role-holder 16

Discussion: Counting the Number of Guests (1/3) Context Role-holder Guest Restaurant Potential player Restaurant Role holder Role-holder Constituent Post Role Constituent Guest Role Potential player Restaurant Post Role Constituent Role Person When playable we count the number of guests playable Class of a restaurant in a month. Context Role holder Role-holder Instance I t Restaurant Guest-1 Role-holder If we need to know in what A Restaurant A orderde o e o each guest comes Role-holder Ies- Ies-1 Constituent-1 Guest-2 Restaurant A Constituent Role-1 John playing Role-holder Guest Post Role Role-playing Restaurant A of Restaurant A Ico- Ico-1 of Role Instance Constituent thing Constituent-2 C tit t 2 Instance of Post Role playing Role-playing thing If we want to count only total Restaurant A Mary playing number of guests Constituent Role-2 Legends Role-playing Instance of playing depend on playable/playing thing Constituent R l C tit t Role instance-of Role-playing thing relationship between role-holder and individual role-holder 2010/10/12 EKAW2010 17

Discussion: Counting the number of Guests(2/3) Services for Guests Context Role-holder Guest Potential player Restaurant Frequent When you want toRole-holder Restaurant Role holder customer serve special menu to i l Constituent t Post Role Post Role Constituent frequent customer. player Role Potential SubClassOf Guest Restaurant Post Role Constituent Role Person playable playable Class Context Role holder Role-holder Instance I t Restaurant Guest-1 Role-holder A Frequent Restaurant A Role-holder o e o de customer Post Role of R t f Restaurant A t Constituent-1 Ies Guest-2 Restaurant A Constituent Role-1 John playing Role-holder Guest Post Role Instance of Role-playing of Restaurant A thing Restaurant A Constituent Role All guests Constituent-2 C tit t 2 are served Instance of playing Role-playing thing Post Role the sameRestaurant A at service Mary the restaurant.Role-2 playing Constituent we need toLegends know how many times Role-playing depend on playable/playing thing Instance of Constituent R l C tit t Role playing each person comes and plays the instance-of Role-playing thing guest post role, using Ies of person. relationship between role-holder and individual role-holder 2010/10/12 EKAW2010 18

Discussion: Counting the number of Guests (3/3) The Guest who Visits Twice  When the same person visits to the restaurant twice. Context First time Role-holder Restaurant Guest-1 Role-holder A Restaurant A Constituent-1 Restaurant A R t t John Not identical Constituent Role-1 playing Guest Post Role Role-playing Instance of in terms of Ies of Restaurant A Instance of Constituent Role thing Post Role playing Role-playing Role playing thing The same Different The same in terms of Ies Second time in terms of Ies in terms of Ies Guest-2 Guest 2 Role-holder Restaurant A Constituent-2 Guest Post Role Restaurant A of Restaurant A Constituent Role-2 John playing Instance of Instance of Role-playing playing thing Post Role Constituent Role Role-playing thing p y g g It is properly managed in what mean guest role-holders are the same or different using these five kinds of instances and their identities. 2010/10/12 EKAW2010 19

Discussion: Parliament members(1/3)  Japanese lower house Role-holder Context Parliament Member of J Lower House-xx J. House xx Role-holder Japanese Parliament Member Lower House Constituent-xx Parliament Member Constituent Role-xx Role xx Person-abc playing l i Instance of Role-playing Post Role Instance of Constituent Role thing playing J. Lower House Post Role Role-playing thing . . . . only one instance of . 480 . parliament post role li t t l exists Role-holder Parliament Member playing of J. Lower House-zz Parliament Member Role Role- Constituent-zz holder Parliament Member Constituent Role-zz Person-xyz playing Instance of Role-playing Constituent Role thing Role-playing thing 2010/10/12 EKAW2010 20

Discussion: Parliament members(2/3)  Japanese lower house (before playing) Role-holder Context Parliament Member of J Lower House-xx J. House xx Role-holder Japanese vacant stateParliament Member Lower House Ico- Ico-1 Constituent-xx Parliament Member Person-abc × Constituent Role-xx Role xx Instance of Ies- Ies I -1 Instance of playing l i Role-playing Post Role thing Constituent Role playing J. Lower House Post Role Role-playing thing They are created by the y . y . predetermined quota (480). . . . There is no need to discuss . 480 in what order parliament constituent roles are created Role-holder Parliament Member or what ID of them. playing of J. Lower House-zz vacant state Member Role Parliament Role- Constituent-zz holder Ico- Ico-480 We can’t identify particular Parliament Member Person-xyz × Ies- Ies-480 Constituent Role-zz playing vacancy. vacancy Instance of Role-playing Constituent Role thing Role-playing thing 2010/10/12 EKAW2010 21

Discussion: Parliament members(3/3)  One parliament member resigns Role-holder Context Parliament Member of J Lower House-xx J. House xx Role-holder 480 Japanese Parliament Member Lower House Ies- Ies-1 Constituent-xx Instance of Parliament Member Post Role Constituent Role-xx Role xx Person-abc playing l i J. Lower House Instance of Role-playing thing Ies- Ies-1 Post Role playing Constituent Role Role-playing thing Unchanged in terms of Ies Different in terms of Ies Role-holder R l h ld Parliament Member of J. Lower House-xx Role-holder 480 Parliament Member Ies- Ies-x Constituent-xx J. Lower House Parliament Member Ies- Ies-1 Post Role playing Constituent Role-xx playing Person-abc Instance of Role-playing Post Role Instance of Constituent Role thing Role-playing thing 2010/10/12 EKAW2010 22

Characteristics of Instances Concerning Roles Represented using Four Kinds of Identities  Instances of post role  There is only one post role for each role concept in a context.  W d t discuss I f it We d not need to di do t Ico for it.  It does not change for natural degradation as time goes by because it is immaterial unless the context changes its definition.  It suggests that we don’t have to discuss Iex of post role role.  Instances of constituent role  We can consider the essential property of each constituent role is determined by h b the event of any player’s participation in the context. f l ’ h  We can distinguish between instances of constituent role by the time when it is created (in what order it is created) in terms of Ies.  We can use Ico if there is no need to discuss in which time and/or in what order they are created. e.g. parliament constituent roles.  Creation of instances of constituent roles  In the case where f d number of roles are predetermined h h fixed b f l d d (e.g. parliament member) →They are created in advance by that number and exist in vacancy.  In the case of no predetermined quota (e.g. guests of a restaurant) →They are created at the same time of new players’ participation. 2010/10/12 EKAW2010 23

Concluding Remarks  Conclusion  Considerations of 4 kinds of instance identities  Identity for Exactness (Numerical identity)  Identity for Essentiality  Identity for Counting  Identity for Replacement  Identity of role concept post role vs. constituent role   These considerations would provide a fundamental theory to discuss identity and contribute theoretically to instance management on computer system based on ontology.  Future work  Development of a theoretical framework for management of identity based on the consideration.  Implementation of the framework in Hozo, an ontology building tool I l i f h f ki H l b ildi l developed by us. 2010/10/12 EKAW2010 24

Acknowledgement Thank you for your attention! Hozo are available at http://www.hozo.jp http://www hozo jp 2010/10/12 EKAW2010 25

A complicated problem of parts replacement of bikes e.g. we assume two wheels as bike A’s essential property Unchanged in terms of Ire Different in terms of Ies e e e s o es Replacement of all parts except its i two wheels h l Ies1 A Ies1 A Ies3 A A’ Ire1 Ire1 Ire1 Ies1 A Ire1 Ies2 Ies4（Ies1） Ies4（Ies1） B B B’ Ire2 Ire2 Ire2 Make another new two bike using parts exchange the removed form A t1 t2 wheels are t3 two wheels t4 installed Unchanged in terms of Ire Different in terms of Ies we can deal with such complicated change of instances in each time points appropriately. 2010/10/12 EKAW2010 26

Identities of constituent role and post role  Instances of post role  It should correspond to a kind of specification of properties and functions of what a player is expected to play [Guarino 98, Massolo 04].  There is only one post role for each role concept in a context.  We do not need to discuss Ico for it.  It does not change for natural degradation as time goes by because it is immaterial nless immate ial unless the context changes its definition. conte t definition  It suggests that we don’t have to discuss Iex of post role.  Instances of constituent role  We can consider the essential property of each constituent role is determined by the event of any player’s participation in the context.  We can distinguish between instances of constituent role by the time when it is created (in what order it is created) in terms of Ies.  We can use Ico if there is no need to discuss in which time and/or in what order they are created. e.g. parliament constituent roles.  Creation of instances of constituent roles  In the case where fixed number of roles are predetermined (e.g. teachers of a school) →They are created in advance by that number and exist in unplayed states.  In the case of no predetermined quota (e.g. guests of a restaurant) →They are created at the same time of new players’ participation. 2010/10/12 EKAW2010 27

Classification of Identity(2)  Synchronic and Diachronic Identities  Synchronic identity  Identity which represents the fact that two individuals are the same thing at a given time.  e.g. “While one hour from 10:00 to 11:00 and one hour from 11:00 to 12:00 are different as a time interval, they are the same as a quantity of time.”  e.g. "the evening star and the morning star are the same star, that is, Venus, though they have different names”.  Diachronic identity  Identity which discusses the sameness of instances at two time points.  e.g. “Whether Taro, an instance of person, at present is the same person with the person five minutes ago or not ”  e.g. “Whether an instance of bike and the bike some of whose parts are replaced are the same or not ” 2010/10/12 EKAW2010 28

Practical Considerations on Identity for Instance Management in Ontological Investigation

by Kouji Kozaki on Oct 20, 2010

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Practical Considerations on Identity for Instance Management in Ontological Investigation — Presentation Transcript