Methodological Preliminaries Supervised versus Unsupervised Learning: In supervised learning(classification), the sense label of each word occurrence is provided in the training set; whereas, in unsupervised learning (clustering), it is not provided Pseudowords: used to generate artificial evaluation data for comparison and improvements of text-processing algorithms e.g, replace each of two words(e.g,, bell and book) with a psuedoword(e.g, bell-book a Upper and Lower Bounds on Performance: used to find out how well an algorithm performs relative to the difficulty of the task Upper: human performance Lower: baseline using highest frequency alternative(best of 2 versus 10) 20212/5 Natural Language Processing--Word Sense Disambiguation2021/2/5 Natural Language Processing -- Word Sense Disambiguation 5 Methodological Preliminaries ◼ Supervised versus Unsupervised Learning: In supervised learning (classification), the sense label of each word occurrence is provided in the training set; whereas, in unsupervised learning (clustering), it is not provided. ◼ Pseudowords: used to generate artificial evaluation data for comparison and improvements of text-processing algorithms, e.g., replace each of two words (e.g., bell and book) with a psuedoword (e.g., bell-book). ◼ Upper and Lower Bounds on Performance: used to find out how well an algorithm performs relative to the difficulty of the task. ◼ – Upper: human performance ◼ – Lower: baseline using highest frequency alternative (best of 2 versus 10)