2. © Tefko Saracevic, Rutgers University1 Interaction in information retrieval There is MUCH more to searching than knowing computers, networks & commands, as there is more to writing than knowing word processing packages

3. © Tefko Saracevic, Rutgers University2 IR as interaction n If USER & USE central: Interaction is a dominant feature of contemporary IR n Interaction has many facets: u with systems, technology u with texts viewed/retrieved u intermediaries with people n Several interactive IR models u none as widely accepted as traditional IR model n Broader area: human-computer interaction (HCI) studies

4. © Tefko Saracevic, Rutgers University3 HCI: broader concepts “Any interaction takes place through one or more interfaces & involves two or more participants who each have one or more purposes for the interaction” Storrs, 1994 n Participants: people & artifacts - ‘computer’ (everything in it) n Interface: a common boundary n Issue: identification of important aspects, roles of each

5. © Tefko Saracevic, Rutgers University4 HCI … definitions “Interaction is the exchange of information between participants where each has the purpose of using the exchange to change the state of itself or of one or more of others” “An interaction is a dialogue for the purpose of modifying the state of one or more participants” n n Key concepts: exchange, change

6. © Tefko Saracevic, Rutgers University5 IR interaction is... “... the interactive communication processes that occur during the retrieval of information by involving all the major participants in IR, i.e. the user, the intermediary, and the IR system.” Ingwersen, 1992 n Involved: u users u intermediaries (possibly) u everything in IR system u communication processes - exchange of information

7. © Tefko Saracevic, Rutgers University6 Central questions n What variables are involved? u models give lists n How do they affect the process? How to control? u experiments, experience, observation give answers n Do given interventions or communications improve or degrade the process? u e.g. searcher’s (intermediaries or end-users) actions n Can systems be designed so that searcher’s intervention improves performance?

8. © Tefko Saracevic, Rutgers University7 Interactive IR models n Several models proposed u none as widely accepted as the traditional IR model n They all try to incorporate u information objects (“texts”): u IR system & setting u interface u intermediary, if present u user’s characteristics F cognitive aspects; task; problem; interest; goal; preferences... u social environment u variety of processes between them all.

9. © Tefko Saracevic, Rutgers University8 User modeling n Identifying elements about a user that impact interaction, searching, types of retrieval …: u who is the user (e.g. education) u what is the problem, task at hand u what is the need; question u how much s/he knows about it u what will be used for u how much wanted, how fast u what environment is involved n Much more than just a question u Related to reference interview

10. © Tefko Saracevic, Rutgers University9 Stratified model - start: A-C-A model of inf. use n Assumption: Users interact with IR systems to use information n A-C-A model components: u Acquisition: getting information u Cognition: absorbing information u Application: using absorbed information n Could be re-iterative n Each involves u different aspects, elements u interplays between them n Basis for interaction model

11. © Tefko Saracevic, Rutgers University10 Stratified model n Interaction: sequence of processes/episodes occurring in several levels or strata = INTREPLAY between levels n Structure: u Several User levels u Produce a Query - has characteristics u Several ‘Computer’ levels u They all meet on the Surface level u Dialogue enabled by Interface F user utterances F computer ‘utterances’ n Adaptation/changes in all n Geared toward Information use

12. © Tefko Saracevic, Rutgers University11 Elements in the stratified model of IR interaction Situational tasks... Affective intent.. Query characteristics Adaptation INTERFACE Engineering hardware, capacities... Processing software, algorithms... Adaptation INTERACTION LEVELS/STRATA Cognitive knowledge structure... Content information resources - texts representation... Surface level ‘COMPUTER’ USER Use of information

13. © Tefko Saracevic, Rutgers University12 Roles of levels or strata n Defining of what’s involved u whassup? n Help in recognition/separation of differing variables u each strata or level involves different elements, roles, & processes n Observation of interaction between strata - complex dynamics

14. © Tefko Saracevic, Rutgers University13 Interplay between levels n Interplay on user side: u Cognitive: between cognitive structures of texts & users u Affective: between intentions & other u Situational: between texts & tasks n Similar interplay on computer side n Surface: u searching, navigation, browsing, display, visualization, query characterization n Interplay judgments in searching: u evaluation of results - relevance u Changing of models: situation, need... u selection of search terms u resulting modifications - feedback

15. © Tefko Saracevic, Rutgers University14 Intermediaries - YOU n Intermediaries could participate as an additional interface - many roles: u diagnostic help in problem, query formulation u system interface handling u selection, interpretation & manipulation of inf. resources u interpretation of results u education of users u enablers of end-users n Basic role: optimizing results n Act in processes at different levels

16. © Tefko Saracevic, Rutgers University15 Implications n Interaction central to IR including in searching of the Web n We see it on the surface level u But result of MANY variables, levels & their interplay n IR interaction requires knowledge of these levels & interplays u many users have difficulties u so do many professionals n Design of interfaces for interaction still lacking n People compensate in many ways including trial & error, failures

17. © Tefko Saracevic, Rutgers University16 What happens in searching? n Highly reiterative process u back & forth between user modeling & (re)formulating search strategy u goes on & on in many feedback loops, twists & turns, shifts n Search strategy (the big picture) u selection/reselection of sources u stating a query (search statement) from a question F terms, their expansions, logic, qualifications, limitations

18. © Tefko Saracevic, Rutgers University17 Searching … (cont.) n Search tactics (action steps) u what to do first, next u e.g. from broad to narrow searches u format of results n Evaluation of results u as to magnitude - how much? u as to relevance - how well? u feedback to change after that F user model - e.g. question F strategy - e.g. files, query F tactics - e.g. narrowing, broadening

19. © Tefko Saracevic, Rutgers University18 Berry-picking model of a search & searcher ( Bates) n “…moving through many actions towards a general goal of satisfactory completion of research related to information need.” u query is shifting (continually) u searcher (user) may move through a variety of sources u new information may provide new ideas, new directions u question is not satisfied by a single set of answers, but by a series of selections & bits of information found along the way

20. © Tefko Saracevic, Rutgers University19 Implications (Shuman) n Prepare carefully n Understand your opponent - u e.g. Dialog, Lexis-Nexis n Anticipate u e.g. hidden meaning of terms n Have a contingency plan u assessing odds of success or points of diminishing returns n Avoid ambiguity u inherent in language n Stay loose!