Cognitive Systems 2

Exercise 1

One question developers of navigational assistance solutions may be interested in is the following:
Is memory for an unknown outdoor environment (e.g., some part of a city) better after exploring it with or without a map?

Design a psychological investigation, adhering to the six rules introduced in the lecture, to answer this question.

A proper description of the proposed psychological investigation will include detailed descriptions of:

• How many subjects are investigated, how are they selected?
  
• What kind of materials and / or tasks are used in the investigation?
  
• What exactly is the procedure of testing the participants?
  
• Which measures are used?
  
• What are the hypotheses? (Be more specific than just saying memory is better with / without a map!)

Exercise 2

On the basis of the Eaters world introduced in part 2 of the Soar tutorial, create the following special eaters:

a) The bonus-food-despiser eater: this eater does not like bonus food and never eats it. When it is facing bonus food, it either tries to bypass the bonus food (preferred choice) or (if there is no normal food around) it jumps over the bonus food to get more normal food.

b) The smart bonus-food-lover eater: it tries to eat as little normal food as possible by exploiting the vertical bonus food lines and by making use of the fact that bonus food is available in regular vertical lines with known fixed distances between each other.

c) The lazy jump-over-the-wall-robber eater: this guy makes as few moves as possible and employs two alternating strategies: (1) it places itself next to a wall; (2) when another eater passes behind the wall and the score of the other eater is higher than its own score, then the eater jumps onto the other one which (as described on the first page of Part II of the tutorial) results in their scores being averaged.

Exercise 3

Extend the sentence verification system presented in the 4th unit of the ACT-R tutorial:

a) Such that the system properly understands and encodes sentences presented in passive voice.

b) Such that it is able to respond to the test sentences provided by the experiment system. The cognitive model should be able to compare a given test sentence with the corresponding facts stored in memory and to respond by pressing the appropriate key.

Hints how to address both tasks are given in the tutorial unit.

Exercise 4

Develop a COGENT model that is able to solve the Jealous Husbands problem cited in Chapter 4 of Cooper's book on "Modeling high-level cognitive processes" (the model should solve the problem in the minimum number of moves). The problem exhibits many analogies with the Missionaries and Cannibals problem discussed in the text and you can orient you solution to the steps discussed there. You may want to check the model archive section on the COGENT web site.
p.s.: sorry for the gender-biased formulation of this 30-year-old problem; of course, nowadays jealousy my apply to wives as well :-)

Thomas Barkowsky / 06 Jan 06