The Justificatory Structure of the NCBO BioPortal Ontologies
Transcription
The Justificatory Structure of the NCBO BioPortal Ontologies
The Justificatory Structure of the NCBO BioPortal Ontologies Samantha Bail, Bijan Parsia, Uli Sattler The University of Manchester, UK 26/10/2011, ISWC 2011 Monday, November 14, 2011 Background: OWL Justifications Definition A justification for an entailment η is a minimal subset of the ontology which is sufficient for • Justifications pinpoint the causes for an entailment ‣ We deal with a potentially smaller set of axioms ontology (set of axioms) S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 entails entailment (axiom) The Justificatory Structure of the NCBO BioPortal Ontologies 2 Background: OWL Justifications Definition A justification for an entailment η is a minimal subset of the ontology which is sufficient for • Justifications pinpoint the causes for an entailment ‣ We deal with a potentially smaller set of axioms justification (set of axioms) entails S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 entailment (axiom) The Justificatory Structure of the NCBO BioPortal Ontologies 3 Background: OWL Justifications Definition A justification for an entailment η is a minimal subset of the ontology which is sufficient for • Best understood explanation type ‣ for ontology debugging (understanding & fixing errors) ‣ for ontology comprehension justification (set of axioms) entails S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 entailment (axiom) The Justificatory Structure of the NCBO BioPortal Ontologies 4 Background: OWL Justifications Definition A justification for an entailment η is a minimal subset of the ontology which is sufficient for • A single entailment can have more than 1 justification ‣ Potentially exponentially many justifications ‣ Up to several thousand found in real-life ontologies entailment (axiom) S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 5 Multiple Justifications Complicate • 1 justification for 1 entailment: OK (well, depends!) • Multiple justifications for 1 entailment: ‣ We can consider them one by one... ‣ ...but this might lead to non-optimal repair! • Multiple justifications for multiple entailments ‣ Where to start? • Dozens or hundreds: Give up! ‣ Cognitive overload for users S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 6 Multiple Justifications Complicate • Thus far only little effort to tackle this problem • Approaches based on relations between justifications: ‣ root & derived justifications [1,2] ‣ axiom power (Swoop tool [3]) [1] A. Kalyanpur, B. Parsia, E. Sirin, and J. Hendler. Debugging unsatisfiable classes in OWL ontologies. J. Web Semantics, 2005. [2] T. Meyer, K. Moodley, and I. Varzinczak. First steps in the computation of root justifications. In Proc. of ARCOE-10, 2010. [3] A. Kalyanpur, B. Parsia, E. Sirin, B. C. Grau, and J. A. Hendler. Swoop: A web ontology editing browser. J. Web Semantics, 2006. S. Bail, B. Parsia, U. 7 The Justificatory Structure of the NCBO BioPortal Ontologies Sattler Monday, November 14, 2011 Multiple Justifications Complicate • Thus far only little effort to tackle this problem • Approaches based on relations between justifications: ‣ root & derived justifications [1,2] ‣ axiom power (Swoop tool [3]) Justificatory Structure The set of structural relations between justifications for single and multiple [1] A. Kalyanpur, B. Parsia, E. Sirin, and J. Hendler. Debugging unsatisfiable classes in OWL ontologies. J. Web Semantics, 2005. [2] T. Meyer, K. Moodley, and I. Varzinczak. First steps in the computation of root justifications. In Proc. of ARCOE-10, 2010. [3] A. Kalyanpur, B. Parsia, E. Sirin, B. C. Grau, and J. A. Hendler. Swoop: A web ontology editing browser. J. Web Semantics, 2006. S. Bail, B. Parsia, U. 7 The Justificatory Structure of the NCBO BioPortal Ontologies Sattler Monday, November 14, 2011 Justificatory Structure: Motivation 1. How prevalent are multiple justifications? 2. Can we make use of structural relationships for... a) improved debugging support? b) understanding the ontology? 3. Can we derive useful metrics from the justificatory structure? S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 8 Justificatory Structure: Representation • JGraph framework ‣ ‣ Justifications and their relations represented as graph ‣ Edges = {axiom occurs in justification, justification for entailment} ax9 Nodes = {entailments, axioms in justifications, justifications} ax10 ax8 just2 ax6 just1 ax2 just2 just3 ax7 S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 9 Justificatory Structure: Structural • Justifications per entailment • Size of justifications (number of axioms) • Self-justifications (J = η) • Trivial entailments (O \ η ⊭η) • Graph components ‣ number ‣ size ax9 ax10 ax8 ax7 S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 just2 ax6 just1 ax2 just2 just3 The Justificatory Structure of the NCBO BioPortal Ontologies 10 Justificatory Structure: Structural • Axiom power (number of justifications an axiom occurs in) • % of ontology axioms in justifications • Overlapping justifications ‣ 1 axiom (➞ axiom power) ax9 ‣ multiple axioms ‣ subsets (= root&derived)ax10 ax8 ax7 S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 just2 ax6 just1 ax2 just2 just3 The Justificatory Structure of the NCBO BioPortal Ontologies 11 BioPortal Survey: Workflow Input: 218 BioPortal OWL ontologies Compute entailments Prune ontologies with unsatisfiable classes, imports, only trivial Compute justifications Generate JGraphs for remaining 35 ont. S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 Compute statistics The Justificatory Structure of the NCBO BioPortal Ontologies 12 BioPortal Survey: Workflow Input: 218 BioPortal OWL ontologies Compute entailments Prune ontologies with unsatisfiable classes, imports, only trivial “Trivial”: O \ η ⊭η for all η Compute justifications Generate JGraphs for remaining 35 ont. S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 Compute statistics The Justificatory Structure of the NCBO BioPortal Ontologies 12 BioPortal Survey: Results • Basic stats: ‣ 35 ontologies (ranging from 85 to ~170,000 axioms) ‣ 12,010 non-trivial entailments ‣ 7,176 distinct non-self-justifications ‣ containing 14,616 axioms ‣ 2,340 self-justifications • No correlations between ‣ ontology size and number of entailments (ρ=0.18) S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 13 Log scale Monday, November 14, 2011 Monday, November 14, 2011 Monday, November 14, 2011 Monday, November 14, 2011 Monday, November 14, 2011 Ontology DL Vertebrate EL++ 307 Evidence Codes EL++ 321 Monday, November 14, 2011 Self-Just 6 Non-SelfJust 6 112 112 59 Axioms Entailments 0 Ontology DL Vertebrate EL++ 307 Evidence Codes EL++ 321 Vertebrate Anatomy Monday, November 14, 2011 Self-Just 6 Non-SelfJust 6 112 112 59 Axioms Entailments 0 Ontology DL Vertebrate EL++ 307 Evidence Codes EL++ 321 ax34 ax35 ax27 Vertebrate Anatomy Monday, November 14, 2011 Self-Just 6 Non-SelfJust 6 112 112 59 Axioms Entailments ax26 ax29 just5 ax36 ax28 ax24 ax22 0 ax32 ax19 ax21 ax23 just2 just3 just6 just1 just4 ax30 ax33 ax20 ax25 ax31 Ontology DL Vertebrate EL++ 307 Evidence Codes EL++ 321 ax34 ax35 ax27 Vertebrate Anatomy Evidence Codes (part) Monday, November 14, 2011 Self-Just 6 Non-SelfJust 6 112 112 59 Axioms Entailments ax26 ax29 just5 ax36 ax28 ax24 ax22 0 ax32 ax19 ax21 ax23 just2 just3 just6 just1 just4 ax30 ax33 ax20 ax25 ax31 41 DL Vertebrate EL++ 307 Evidence Codes EL++ 321 ax34 ax35 ax27 Vertebrate Anatomy ax402 117 49 Ontology just47 ax403 ax288 ax255 just9 just58 just65 just4 ax275 ax410 ax273 ax256 just110 just45 Evidence Codes (part) Monday, November 14, 2011 ax26 ax29 just5 ax36 ax254 ax236 just133 112 112 59 ax28 ax19 just2 just3 just6 just1 just4 ax30 ax33 ax20 ax25 ax31 ax278 just98 ax399 ax277 ax238 ax259 just168 just131 just84 just114 ax279 ax289 ax295 ax261 just130 just15 ax260 just18 ax24 ax22 0 ax32 ax235 just92 Self-Just 6 Non-SelfJust 6 Axioms Entailments ax263 ax243 just76 just23 just85 ax262 ax264 ax365 ax244 just2 just14 just70 ax21 ax23 ax237 just33 ax239 ax232 a just107 just56 just120 ax355 ax233 ax421 just6 Ontology DL Vertebrate EL++ 307 Evidence Codes EL++ 321 ax34 ax35 ax27 Vertebrate Anatomy ax369 ax370 ax299 ax331 ax270 ax268 ax267 ax385 ax265 ax384 ax362 ax363 ax303 ax393 just21 just91 just162 ax271 just132 just39 just62 just19 just124 just134 just90 just88 just105 just159 just136 just145 ax371 ax379 ax372 ax300 ax332 ax272 ax269 ax398 ax266 ax386 ax419 ax364 ax315 ax305 ax394 just125 just156 just83 just59 just66 just44 ax283 ax304 ax338 ax276 ax291 ax292 ax328 ax416 ax415 just5 just167 just143 just154 just42 just150 just8 just37 ax309 ax284 ax339 ax246 ax293 ax407 ax329 ax417 ax245 ax318 just77 just1 just106 just155 just17 just123 just149 ax395 just36 ax29 just5 ax36 ax28 just3 just6 just1 just4 ax30 ax33 ax20 ax25 ax31 ax413 ax412 ax311 ax247 ax377 ax376 ax348 ax310 ax360 ax359 ax222 ax221 ax307 ax306 ax220 ax380 ax381 ax367 ax353 just113 just164 just158 just53 just148 just152 just171 just40 just11 just118 just48 just30 just127 just82 just63 just68 just38 just147 just166 just117 ax396 ax257 ax414 ax391 ax312 ax248 ax378 ax392 ax349 ax302 ax361 ax387 ax224 ax223 ax308 ax397 ax411 ax382 ax390 ax368 ax282 ax249 just27 just54 just25 just26 just29 just41 just111 just81 59 just2 just52 just170 112 ax19 ax389 just112 112 just94 ax402 just47 ax403 ax288 ax255 just9 just58 just65 just4 ax275 ax410 ax273 ax256 just110 ax254 just45 ax235 just92 ax236 just133 ax278 just98 ax399 ax277 ax238 ax259 just168 just131 just84 just114 ax279 ax289 ax295 ax261 just130 just15 ax260 just18 ax263 ax243 just76 just23 just85 ax262 ax264 ax365 ax244 just2 just14 just70 ax237 just33 ax239 ax232 ax252 ax214 ax319 ax212 ax213 ax258 ax336 ax330 ax335 ax241 ax313 ax251 ax250 ax400 ax350 ax420 ax357 ax286 ax217 ax23 ax326 ax280 ax373 ax408 ax316 ax341 ax340 ax321 ax323 ax322 ax227 ax225 ax226 ax229 ax230 just120 just146 just12 just108 just109 just31 just35 just55 just121 just49 just165 just43 just75 just116 just153 just3 just99 just119 just101 just126 just102 just61 just129 just74 just89 just22 just169 just144 just46 just97 just73 just69 just137 just64 just157 just160 just80 just135 just72 just50 just28 just142 just93 just79 just10 just24 just96 ax355 ax233 ax421 ax405 ax388 ax375 ax290 ax327 ax374 ax346 ax215 ax320 ax234 ax240 ax334 ax281 ax351 ax337 ax296 ax343 ax406 ax409 ax418 ax317 ax242 ax314 ax253 ax347 ax274 ax401 ax422 ax294 ax285 ax356 ax358 ax287 ax219 ax383 ax301 ax352 ax342 ax354 ax324 ax366 ax297 ax228 ax344 ax231 just13 just95 just7 just141 just71 just60 just138 just20 just16 just161 just139 just100 just51 just87 just57 just32 just140 just34 just122 just163 just78 ax345 ax21 just56 just151 ax325 ax22 just107 just6 ax404 ax24 0 ax32 ax298 Evidence Codes (part) Monday, November 14, 2011 ax26 just104 just115 Self-Just 6 Non-SelfJust 6 Axioms Entailments just103 ax218 ax216 just67 just86 ax333 just128 BioPortal Survey: Results • Multiple justifications ‣ occur in 71.4% of ontologies ‣ 1.3 justifications per entailment (without self-justifications) ‣ max: 236 (Gene Ontology Ext.) S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 19 BioPortal Survey: Results • Multiple justifications ‣ occur in 71.4% of ontologies ‣ 1.3 justifications per entailment (without self-justifications) >2 justifications 14.3% 1 justification ‣ max: 236 (Gene Ontology Ext.) 28.6% (1, 2] justifications 57.1% Average justifications per entailment across ontologies S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 19 BioPortal Survey: Results • Axiom power ‣ avg axiom power 3.0 (axiom occurs in 3 justifications) ‣ max 510 justifications for 1 axiom S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 20 BioPortal Survey: Results • Axiom power ‣ avg axiom power 3.0 (axiom occurs in 3 justifications) ‣ max 510 justifications for 1 axiom 3% 11% 34% 51% exactly 1 >1, <=2 Average axiom power >2, <=10 (proportion of > 10 ontologies) S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 20 BioPortal Survey: Results • Justification equality ‣ 51% of justifications have more than 1 entailment S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 21 BioPortal Survey: Results • Justification equality ‣ 51% of justifications have more than 1 entailment Basic Formal Ontology (BFO) S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 21 BioPortal Survey: Results • Justification equality ‣ 51% of justifications have more than 1 entailment Basic Formal Ontology (BFO) S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 21 Conclusions 1. How prevalent are multiple justifications? ‣ 71.4% of surveyed ontologies have multiple justifications ‣ Small number of multiple justifications on average ‣ Size & DL expressivity of ontology are no S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 22 Conclusions 2. a) Can we make use of structural relationships for improved debugging support? ‣ Large degree of interaction between justifications ‣ Considering entailments and justifications in isolation ignores these relationships ‣ Optimal repair strategies: Look at multiple justifications ‣ Future work: Explore possible repair strategies S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 23 Conclusions 2. b) Can we make use of structural relationships for understanding the ontology? ‣ Self-justifications, equal justifications, axiom power, activity... make implicit structure explicit ‣ Representation helps exploring multiple justifications S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 24 Conclusions 3. Can we derive useful metrics from the justificatory structure? ‣ See Vertebrate Anatomy vs Evidence Codes ‣ More information than counting axioms ‣ DL expressivity does not imply complexity ‣ Structural aspects may be indicators for richness of an ontology S. Bail, B. Parsia, U. Sattler Monday, November 14, 2011 The Justificatory Structure of the NCBO BioPortal Ontologies 25 just10 ax84 ax74 ax101 ax104 ax78 ax129 ax100 just9 ax87 ax126 ax80 just23 ax93 just15 ax105 just27 ax90 ax110 ax88 just16 ax91 ax102 ax114 ax94 ax79 just18 Thank you! ax136 ax118 ax108 just2 just8 ax95 just26 ax82 bails@cs.man.ac.uk ax86 just21 ax133 ax72 ax119 just20 ax97 ax98 ax132 ax75 ax120 just19 ax85 ax92 just25 ax131 just24 ax127 ax122 ax113 ax103 ax99 ax128 ax140 ax125 ax96 ax130 just11 just12 just4 ax106 just1 ax124 ax121 ax76 just3 ax123 Monday, November 14, 2011 ax73 ax77 ax107 just5 just13