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May 19, 2010

Decision-making over time

Lately I've been looking at applying game theory to my problem. (Previous entry:Strategy and Process)

Recently, I had an invigorating conversation with a former colleague (yo Dylan!) about AI, planning, memes, feedback/reinforcement, swarm intelligence (or mind as a set of autonomous agents), influence diagrams and decision theory, and many other things. It was super awesome.

The point of this post is to record a take-away thought from this conversation that I think is important. We had sketched out a sample influence diagram (sort of like this example from a previous post, Decision theory for teaching strategies) and pointed out Event nodes, Decision nodes, and utility nodes. At the time, I couldn't remember how "Event" nodes took into account an agent's observations. I think we had been talking about agent preceptors and actuators. Later, I remembered that "observables" take the form of "givens" in a conditional probability, and an event is a statement of conditional probability. I have talked about this before, too, in Learned some Stats lingo.

Anyway, the important point is that "Calculating Optimal Policy is Important OVER TIME." I figure that an influence diagram looks "frozen". If your givens in the Events are changing all the time, and what if the Utility function itself is changing, and your decisions have to change... this is STRATEGY, and this takes into account the dimension of Time.

I look at a couple different optimal policy calculations in this previous entry, Conditional probabilities, and "the argmax thinggy". Notice how one of them takes time into account and the other does not. I would say that Time is a critical dimension in planning.

The calculation in that post lacks an overall picture of process.

(On Twitter, I summarized this entry as: Decision theory- optimal policy over time)

Posted by Frozone Permalink on May 19, 2010 12:05 PM | Comments (0)
categorized under Pedagogical modelling




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Index to Steph's Notes

Feb. 24th 2007 - Weee! This new part of my website is not an entry, but rather a permanent fixture whose purpose is to "Look Down on All Those Notes With Some Grand Vision of Organization". Wish me luck. LOL
  1. Representing meta-data (fuel) & the different kinds of "hooks" that intelligent systems can use (how fuel is injected into the motor of the engine)
    1. Motivation: Semantic net / Rationalizable to a machine
      1. Semantic network
      2. Genetic graph
      3. Prerequisite AND/OR graph
      4. Constraint Satisfaction Problems
      5. Bayesian networks / causal graphs
    2. Technology & Philosophy: RDF, modus ponens,
      1. Predicates, Logic & situation calculus
        1. When in doubt, do some math
    3. What kinds of data? - What kinds of meta-data would an AIEd system possibly need, and how is it represented?
      1. task domain knowledge
      2. "is-prerequisite-to"-type knowledge
        1. Jackpot! A pedagogical ontology
      3. interactions with learning objects & other learners - (location, composition is-a/part-of, sequencing by restricting navigation, personalization, ontologies for LO context)
        1. Types of 'Ecological' data
      4. lesson plans, curriculum plans, practicing sessions (What is stored, what is generated on the fly? What is remembered?)
        1. Agent memory
    4. How to organize it - When is it stored in a database? Meta-data? Agent memory banks? Protocols? Repositories? XML files? Home-servers? WSDL services? Frameworks? Portable banks? P2P access?
      1. Database of object-agent interactions
      2. Concept of "Home" on a P2P network -- maybe the bulk of a learning object's usage data is on its home server and can be queried using WSDL or something ? Similar homes for each student's usage history, etc. Baggage problem.
    5. Links to the ontologies
      1. referring to a concept/relationship - ex. AgentOwl?
        1. Using Vocabularies in JENA
        2. Referring to a concept/relationship in an ontology
        3. Improved: Referring to a concept/relationship in an ontology
        4. Using OWL to reference constraints in tutoring systems
    6. Generation of this data
      1. Rationalization: For use by other AIEd systems
      2. What is generated - discuss items under part I.C.
      3. When it's generated - describe procedural model, which parts of the engine generate what (isa-part-of data, XML feeds, web services, meta data bout groups and collaboration, protocols, examples Friend of A Friend FOAF project)
        1. Thinking about the system's RDF output
      4. Technical notes of HOW it's generated: JENA, issues of implementation demo, my Hermione & Ron agent examples, lol
      5. Usage of this generated data - see part IV. A.
  2. Given the engine, who uses it?
    1. Students / Learners / "Me"
      1. instructional planning, student model, pre-requisites, tutoring, coaching, collaboration,constructivism
    2. Teachers / Educators / "Me"
      1. putting together lessons
      2. be able to browse through task domain knowledge in an objective / encyclopaedia format, then be able to pick-and-choose what you need for your students
      3. compose examples, design explanations, pull together diagrams, learning objects, etc. Haystack Relo?
    3. Administration / Governement / Structure / Crowd Control
      1. as restrictions/obstacles/sand pit to the robot in agent environment
      2. can't just have a swarm of students and teachers out there -- need structure of courses, curriculum, objectives, requirements (at least, we do in this day and age!) - Report cards, evaluation, feedback
      3. government, marks, certificates, requirements, funding, curriclum, attendance, delinquent, non-attending, motivation
      4. school''s images, goals, strengths, payroll, HR, security, accounts, permissions, privacy
      5. registration, failed courses
  3. User Environment -- How does this engine work? What does the user see on the screen?
    1. Introduction - Given a background in educational psychology, how does the system present itself -- what does the user see, and were does this data come from? Links to thoughts from part I.)
    2. Task Domain Browsing - Suppose you're you're just idly browsing through the "raw" content. How would it look when it's not wrapped around a learning-context or lesson or tutorial or anything. 'Cross between browsing a raw task domain ontology and browsing a learning object repository.
      1. Cleaning up the data -- Visualizing the data for humans to pick through the task domain and work on it. Suppose the "Subject Expert" discovers an advancement in science and needs to update the "world's" domain knowledge. (I used the "Subject Expert" terminology from Ontologies to Support Learning Design Context - Thanks Chris) How would they make corrections to ontologies and learning objects, or at least point the users of "old" objects towards adopting the newer ones.
      2. "Modes" - Learning & Lessons / Checklist - Homework, Assignments, Courses being taken / Collaborative mode / Teaching mode / Calendar- email -adminisrative mode -- See also the different kinds of scenarios in the ActiveMath system
        1. Educating myself about Education
  4. Evolution of this engine
    1. target some key implementation hooks discussed in part I - design an experiment/demo
      1. scrape a page - (Note, scraping can only give objective data, not in-context dat)
      2. LO repository - related to browsing the task domain?
      3. a learners "To Do" list - where does it come from? Assignments, courses.
      4. sample group scenario
      5. sample teacher lesson planning
      6. sample data "left behind"
      7. sample use of that data
    2. Data mining (for what? lol )
      1. discovery / generation of ontologies - when do you need to hunt for them, and when do you have to have a solidly-known & predictable ontology?
        1. Ontological Engineering: taking a first bite
    3. I/O - where it happens, which languages, protocols, which agents perform i/o and when, precepts, actuators
      1. Role Assignments
        1. Levels of authorization in web applications
      2. My Environment Adapts to me
        1. Displaying feedback from the server on JSP pages (Software engineering considerations)
        2. Sketching out a design (Content planning vs. Delivery planning)
      3. agent negotiations / social structures / ummm... Web 2.0 ?
        1. Towards student modelling
        2. Anatomy of an agent
    4. garbage collection of meta data
      1. Artificial Intelligence & Evolution
        1. Memory Culling: Necessary part of intelligence? (artificial or human)
        2. Applications for the Genetic/Evolutionary algorithm
      2. open learning environments
  5. Agents, pets, grouping, Community modelling
    1. Protocols - finding groups, cyber dollars, state diagrams (?)
    2. "Community Studies" - graphs & communication hubs, types of communities (free-for-all, hierarchy of authority, etc.)
    3. implications of joining a community - what do you share, which parts of your student model are relevant
    4. Walls & sand traps -- deliberate restrictions as problem-solving for learning
    5. Communication channels - individual-to-individual, individual-to-community, chat channels, agent-only "administrative" communications, ex. requests for related learning objects in a particular community, etc.
  6. Educational/Pedagogical focus (this part probably shouldn't be its own section but rather incorporated into the whole picture, but it's separate for me right now because I'm still only just starting to learn about it.)
    1. Semantics - what there is to talk about in Education
      1. ex. Merril's First Principles of Instruction, linking educational terms to AI terms
        1. Educating myself about education
    2. Pedagogical skills for tutors -- supporting human *and* artifical tutors
      1. Modelling teaching strategies
      2. What is teaching?
      3. Decision theory for teaching strategies
      4. My pedagogical issues
      5. Ontological comparisons as spatial relationships
    3. Student modelling - what the machine needs to know about the student, pedagogically-speaking, about learning history/preferences
    4. Roles - Simulated students, Coaches, Tutors, Teachers,