Human Interactions in Mixed Service-Oriented Systems

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An overview of human provided services and mixed service oriented systems is given. The core theme of this research is to support dynamic interactions between humans and services based on evolving interaction preferences.

The application of such a system can be found in crowdsourcing scenarios.

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Human Interactions in Mixed Service-Oriented Systems

  1. 1. Human Interactions in Mixed Systems - Architecture, Protocols, and Algorithms Daniel Schall Distributed Systems Group Institute of Information Systems TU Wienhttp://www.infosys.tuwien.ac.athttp://www.infosys.tuwien.ac.at/prototyp/HPS/HPS_index.html 27. Feb. 2009
  2. 2. Overview• Motivation• Related approaches and challenges• The Human-Provided Services (HPS) framework• Ranking and discovery in interaction networks• Experiments• Conclusion and future work 2
  3. 3. Motivation Paradigm: human and service interactions• Open dynamic ecosystems – People and software services integrated into evolving “solutions“• Communications and coordination – „Anytime-anywhere“ pervasive infrastructures and mobility … software service• Mass collaboration … user – Knowledge sharing and … human/service social interaction interaction 3
  4. 4. Related Work: Approaches and platforms • BPEL4People/WS-HT Process flow Web services • User driven versus modeled tasks in workflow People activity/ human task • Collective intelligence • „Crowdsourcing“ (e.g., Amazon Mechanical Turk) task1 task2 • No collaboration link Tasks task3 between humans Requester task4 Modeling of human interactions in dynamic service-oriented systems Reputation mechanism and expertise ranking in Knowledge sharing large-scale systems platform 4
  5. 5. Challenges (HPS)• Current service-oriented systems only support the definition (interactions with) software services• How to integrate human capabilities in SOA?• How can people create services?My Approach• Human-Provided Services (HPS) to define human capabilities as (Web) service interfaces.• User-driven approach to creating HPSs• Ability to support interactions 5
  6. 6. General Layout HPS Framework User-defined services Human, B4P … human activity Compositions of human Requester and software services … link between activities and human Metrics, Management Design QoS (HPS)• Human-Provided Services (HPS) HPSs – Users-define services – Activity modeling Design: users create services• Unified view – Human and software service depicted using Web services standards 6
  7. 7. Architecture 7
  8. 8. ExampleDiscovery HPS Interactions Definition 8
  9. 9. Designing HPSs• Novelty of HPS: Users can specify activities as (Web) services • E.g., consultant or reporter• Find existing HPSs Reusability • Search and reuse existing HPSs • Similarity ranking based on user profile information• Create New HPS • User tools hiding underlying complexities („Mashup“ like HPS design) • Personal Services = User profile + activities + artifacts (WSDL) 9
  10. 10. Designing HPSs Template for activity types Output (XSD, XSI, XForm) 10
  11. 11. Overview Metrics• Classification of Metrics 11
  12. 12. Challenges (Ranking)• How to find the most relevant expert?• How to calculate the expertise of people in an automated manner?• How to account for changing interests and the skill level in different fields of interest?My Approach• Dynamic Skill and Activity-based PageRank• Interaction mining using link-intensity weights• Personalization based on interaction context• Aggregated importance using query terms 12
  13. 13. Ranking Algorithm: Random surfer model … node Web Graph … surfer … Web link 1/2 1/3 With a certain probability, I will PR (v) 1 jump (“teleport”) toPR (u )    (1   ) a random Web page. vinlinks( u ) | outlinks (v) | N Page et al. (1999), The PageRank Citation Ranking: Bringing Order to the Web. 13
  14. 14. Ranking Algorithm: Behavior model … document Interaction Graph … user 6 5… link 3 1 w1,3 4 w1,2 w2,4 2 I will contact User 2 I will contact some other depending on the link user. For example, to weight w1,2. The link start a new collaboration weight is based on by relaying a message. strength and intensities of interactions. 14
  15. 15. Ranking Algorithm: Interaction context• Users interact in different contexts with different intensities context 1 (e.g., topic = WS Addressing) context 2 (e.g., topic = WS Policy) 2 1 1 Interaction intensity Interaction intensity context 1 context 2• Personalize ranking (i.e., expertise) for different contexts 15
  16. 16. Ranking Algorithm:Calculate the importance of u, v, z: u u… Personalization/ + v… teleportation vectorz v z… wv ,u DSA(u )   vinlinks( u ) wsv DSA(v)  (1   ) w wm WM m pm (u )Iterative algorithm to compute rankings (convergence criteria) Iteration PR(u) PR(v) PR(z) 0 1 1 1 1 1 0.75 1.125 2 1.0625 0.765625 1.1484375 16
  17. 17. Ranking Algorithm: Context-aware DSARank• Approach: Expertise mining in weighted subgraph Each context tag For a given context Perform ranking“Tags” identify the may have different (e.g., c1) create a based on weightedinteraction context. weights (e.g., subgraph. links in subgraph. frequency).• Theorem linearity (Haveliwala 02): w1PR( p1)  w2 PR( p2 )  PR(w1 p1  w2 p2 ) 17
  18. 18. Context-dependent DSARank • (1) Identify context of interactions Context 1 3 („tags“)1 w1,3 4 • (2) Select relevant links and people w1,2 w2,4 • (3) Create weighted subgraph (for 2 context) • (4) Perform mining 4 1 w1,4 User 1’s expertise in context 1 User 1’s expertise in context 2 w1,3 3 Context 2 DSA(u;C )  wc DSAw1 p1(u )  ...  wn pn (u )  cC Calculated offline Combined online E.g., p(u) = w1 IIL(u) + w2 availability(u) based on preferences 18
  19. 19. Results (1/2)• Real dataset (Reality mining)• High interaction intensity influences importance rankings• Expected informedness of users ID Rank Rank (PR) Intensity (out) Intensity (in) (DSA) 43 1 6 2.74 0.58 187 2 90 6.60 8.85 … 50 10 93 4.38 3.14 19
  20. 20. Results (2/2)• Real dataset (Email)• High interaction intensity reveals key people• Best informed users ID Rank (DSA) Rank (PR) Intensity Level 37 1 21 7.31 ... 253 4 170 2.07 347 5 282 1.39 20
  21. 21. Conclusion• Human-Provided Services supporting versatile collaborations• Global importance ranking based on interaction intensities and context• Future work • How to compose interactions between humans and services • Generate HPSs based on user profiles 21
  22. 22. Thanks for your attention! Daniel Schall Distributed Systems Group Institute of Information Systems TU Wienhttp://www.infosys.tuwien.ac.athttp://www.infosys.tuwien.ac.at/prototyp/HPS/HPS_index.html
  23. 23. Backup
  24. 24. Activity Model (1/2)• To manage artifacts, resources and HPSs 24
  25. 25. Activity Model (2/2)• To manage collaboration structure • Actions and related messages • Activities and associated resources • Activities and related subactivities 25
  26. 26. Task Model• To control the status of interactions • Start time, end time, progress • Notifications • Stakeholders (groups) 26
  27. 27. HPS WSDL Example• (1) User specifies activity: „Document review“• (2) Existing service? • Reuse or create new definition („Human-provided review service“)• (3) Framework supports • Automatic translation into low interfaces (WSDL, XForms)• XML Example: • <wsdl:message name="GetReview">: Definition of what a user (HPS) expectes to perform activity • <wsdl:portType name="HPSReviewPortType">: Definition of how the activity is mapped onto an action • <wsdl:binding name="HALSOAPBinding" type="HPSReviewPortType">: Technical binding of HPS to middleware access layer 27
  28. 28. Access Layer Processing• HPS Access Layer as interaction proxy 28
  29. 29. Discovery and Ranking• (1) Logging interactions• (2) Create interaction graph (offline)• (3) Aggregate ranking results based on preferences (online) 29
  30. 30. HPS Discovery• (1) Query string specified by service requester• (2) Matching of HPS capabilities • Return interfaces for interactions (e.g., depending on requester WSDL or forms based representation) • XML Example: Atom Feed referencing <entry> resources associated <title>News Reporters</title> with HPS <linkrel=”alternate” type=” application/atom+xml” href=”/atom/newsreporter.xml” /> <summary>News−reporterservices</summary>• (3) Ranking </entry> „best available“ HPS • Criteria such as expertise • Context dependent (e.g., location)• (4) Runtime interactions HPS Access Layer Message dispatcher/router 30
  31. 31. Ranking Algorithm: Metrics (1/2)• Availability availabili ty (u )   t call vA( u ) call( u ,v ) (u, v)• Link Intensity   1 / |l | i(l )   tcall   calll  1/ |l |  • Interaction Intensity i (l; u ) i(l ) | l |   i (l ) llinks(u ) • Skill/expertise wv ,u SE (u; c)   vinlinks( u ) wsv SE (v; c) 31
  32. 32. Ranking Algorithm: Metrics (2/2)• Interaction Intensity Level (IIL) 2 (1/ 2 )    2    IIL(u )      iout (l; u )   (2   )   iin (l ; u )  2 2    loutlinks(u )       linlinks( u )    • IIL Imbalance imb( IIL)  i in linlinks( u ) (l; u )  i out loutlinks( u ) (l; u )• Passive involvement: imb(IIL) = 1• Active involvement (all interactions outgoing): imb(IIL) = −1 32
  33. 33. Implementation: Interaction Mining• Interaction Logs Email, telephone, etc.• Interaction Graph Filter by context• Algorithms Interaction mining• Results • Context dependent rankings • Query service (online aggregation) 33

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