1. Cognitive Modelling Assignment 1 MODEL 6: MSc Cognitive Science Elaine Cohalan Feb 9 th 2005

2. Single Category Classification Stage 1:

3. Stage 1: Tasks: Come up with a computational model that, for each test item computes that item's degree of membership in the three categories A, B and C. Use the attributes of that test item and compare to the occurrence of those attributes in the 16 training items.

4. Additive Weighted Prototype Model Training Items Given:

5. Developing the Prototypes: Category A:

6. Category B:

7. Category C:

8. Applying Prototypes to Test Items:

9. Correlation of prototype model scores with human scores:

10. Category A:

11. Category B:

12. Category C:

13. Total Correlation:

14. Conjunctions Stage 2:

15. Stage 2: Tasks: Independent Approach to Conjunctions. Constituent Membership scores combined using function sum (A+B).

16. To compute an items membership in a conjunction A&B using the Independent Prototype Model, combine that item’s membership in A and its computed membership in B. Formula for sum(A+B): membership(x, A&B) = sum(A,B) = (membership(x,A) + membership(x,B))

17. Category A and B: Using Prototypes A and B:

18. Correlation with Human Score:

19. Category A and C: Using Prototypes A and C:

20. Correlation with Human Score:

21. Category B and C: Using Prototypes B and C:

22. Correlation with Human Score:

23. Total Correlation for Conjunctions: