Cognitive Modelling, Summer 2002

Seminar Week 1

 

AIMS OF TODAY’S SESSION

·   to go over the main points of the first lecture;

·   to provide an opportunity to ask any questions about the course;

·   to discuss some basic issues concerning

·     AI,

·     cognitive science & cognitive modelling

·     computer-based approaches to cognitive modelling.


 

Reading for today:

 

(1)                Foreword to M Sharples et al, Computers and Thought (1989):  'A Personal View of Artificial Intelligence', by Aaron Sloman

 

(2)           Ch. 3, 'Stored Knowledge', by Steve Torrance, in the same volume:  (Sections 3.1 – 3.6)

 

Cognitive Science:  Some key questions (from Monday’s lecture):

 

How do we

·     use language?

·     solve problems?

·     operate effectively in a complex, dynamic world?

·     learn to carry out these functions?


Cognitive Modelling

 

·            Trying to understand cognitive  processes by building computer models.

 

·            Compare to computer modelling in general

·            Example:  The movie Twister.

·     Building complex computer models to understand more about tornadoes.

·     Practical objective: to save lives.  (Increase warning time from a few seconds to a couple of minutes.)

 

·   See A Sloman, foreword to Computers and Thought p. xx:

 

·   Trinity of science: 

·   empirical

·   theoretical

·   practical

 

Cognitive Science:

 

An interdisciplinary study of mental processes:

 

     which disciplines involved ? ? ? ?

 

Kinds of problems addressed:

·   Empirical

·   Theoretical

·   Practical

 

     what kinds of problems ? ? ? ?

 


 Course Overview:

 

·   Aims of this course

o  AI/computer modelling perspective within cognitive science;

o  basic programming concepts (not practical programming skills)

o  groundwork for later Major and School courses

·   Reading: 

o   Green et al. Cognitive Science: An Introduction.

·   Computer Classes

o   Week 2 onwards

o   working in pairs (if possible)

·   Seminars

o   Week 1 onwards

·   Assignment

o   Log of computer-based experiments

·   Assessment

§     Essay

plus

Unseen exam
Computer models of cognition.

 

Two initial examples:

(a)            BUGGY: simulating children’s subtraction behaviour;

(b)           blocksworld: simulating simple conversations about a basic world of objects.

 

Buggy:  Child A – where is she going wrong?

 

2  3

   4

-----

2  1

 

 

9  2  9

2  3  5

--------

7  1  4

Blocksworlds

See Handout for today.

 

MSBlocks (aka Gblocks)

·                   Program ‘knows’ about ‘microworld’ of boxes of different sizes and colours.

 

·                   Can interpret simple English sentences, like ………

·     Put the big green box on the small green one.

·     Place a blue box on a red one.

·     Is there a large box on the table?

 

·                   Can form plans to execute commands

 

·   Based on Terry Winograd’s SHRDLU.

 

Sloman’s model (design) for an intelligent system.  (pp. xxv – xxvii)

 

Perceptual mechanisms – finding out about the world.

 

Database of information about the world.

 

Analysis and interpretation procedures – making sense of the perceptual input.

 

Reasoning procedures – inferring new knowledge from stored info and new input

 

Database of goals – what the system ‘wants’ (or is directed) to do.

 

Planning procedures – given goals and information, how to produce a sequence of actions to achieve goal.

 

Executive mechanisms – getting the world to change by acting according to the plan.

 

 

Some questions for discussion:

 

HOW FAR DO SHRDLU (AND MSBLOCKS) CONFORM TO THIS MODEL?

 

WHAT ARE THE LIMITATIONS OF THIS MODEL?