Cognitive Modelling Experiment Clodagh Collins. Clodagh Collins.

Model Type Single category classification: Additive weighted prototype model. Single category classification: Additive weighted prototype model. Conjunctions: Interactive approach to conjunctions. Conjunctions: Interactive approach to conjunctions.

Stage 1 Single category classification for categories A, B and C. Single category classification for categories A, B and C. Prototype weightings were computed. Prototype weightings were computed. Weights of the new item’s attribute values were added. Weights of the new item’s attribute values were added. Prototype score was calculated. Prototype score was calculated. W(,C)= no. of occurances of in stored members of C W(,C)= no. of occurances of in stored members of C total no. of occurances of across all categories total no. of occurances of across all categories

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Stage 2 Conjunctive classification for ANDED-PAIRS, A and B, A and C, B and C. Conjunctive classification for ANDED-PAIRS, A and B, A and C, B and C. In each case the list of attribute weights from the two constituents were combined to form the prototype. In each case the list of attribute weights from the two constituents were combined to form the prototype. Combined using average((A+B)/2). Combined using average((A+B)/2). Items were then classified by comparing them to these integrated prototypes. Items were then classified by comparing them to these integrated prototypes.

Prototype for A Prototype for B Dim 1 Dim 2 Dim 3 Dim 1 Dim 2 Dim3 A= 0.8 X= 0.25 C= 0.2 Z= 1 B= 0.75 B= 0.71 Y= 0.5 Y= 0.25 Y= 0.66 X= 0.5 X= 0.25 X= 0.33 X= 0.33 X= 0.25 A= 0.5 X= 0.66 Y= 0.5 Y= 0.25 C= 0 Z= 0 B= 0.25 B= 0.14 A= 0.2 A= 0.16 Y= 0

Prototype for A and B: Av((A +B)/2) Dim 1 Dim 2 Dim 3 A= 0.5 X= 0.25 C= 0.1 Y= 0.5 Y= 0.25 Y= 0.33 X= 0.38 A= 0.33 X=0.5 Z= 0.5 B= 0.5 B= 0.43

Analysis The model’s classification scores were a reasonably good fit to participants’ average classification scores for items as members of single categories ( A: r= 0.87, B: r= 0.92, C: r= 0.91 however some variation was observed in the scores for members of category conjunctions (A and B: r= 0.97, A and C: r= 0.45, B and C: r=O.86). Overall correlation score was r= 0.86.…