COMPSCI 171 Final: 2015-fq-cs-171-final-exam-key
Document Summary
Perfect: ~76% (~148 students), partial: ~18% (~35 students), zero: ~7% (~13 students) A common mistake was to select m=3 and so merge the training and testing error. Another common mistake was to calculate mse as (1/m) ( j (yj - j) )2 instead of the correct (1/m) j (yj - j)2. Perfect: ~95% (~187 students), partial: ~5% (~9 students), zero: ~0% (~0 students) Perfect: ~40% (~78 students), partial: ~35% (~69 students), zero: ~25% (~49 students) A common mistake was to switch cluster #1 and cluster #2. Another common mistake was not to understand k-means clustering at all, leading to lost points. Perfect: ~34% (~67 students), partial: ~58% (~114 students), zero: ~8% (~15 students) A common mistake was not to understand what the cluster dendogram (= tree) was supposed to be. Perfect: ~20% (~40 students), partial: ~80% (~156 students), zero: ~0% (~0 students) A common mistake on 4. d. 1 was to mention only t1 instead of t1, t3, and t4.
