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NLP Assignments for Undergraduates (2) Zhao Hai [email protected] Language Model 1. Show that Good-Turing Estimation is well-founded. i.e., you should prove the sum of all probabilities from it is exactly 1. 2 Syntactic Processing 1. Wh-questions are questions that use a class of words that includes what, where, who, when, whose, which, and how. 1. For each of these words, give the syntactic categories (for example, verb, noun, noun group, adjective, quantifier, prepositional phrase, and so on) in which the words can be used. 2. Justify each classification with some examples that demonstrate it. 3. Use both positive and negative arguments as necessary (such as ”it is one of these because ...,” or ”it can’t be one of these even though it looks like it might, because ...”). Syntactic Processing 2. Given the CFG grammar and a lexicon in the following, please show a trace in the format of the figure mentioned previously adopting a topdown CFG parser for the sentence The man walked the old dog. Grammar: 1. S → NP VP 2. NP → ART N 3. NP → ART ADJ N 4. VP → V 5. VP → V NP Lexicon: the: ART man: N, V walked: V old: ADJ dog: N, V Syntactic Processing 3. Consider the following CFG: S → NP V S → NP AUX V NP → ART N Trace one of the chart parsers in processing the sentence 1 The 2 man 3 is 4 laughing 5 with the lexicon entries: the: ART man: N is: AUX laughing: V Show every step of the parse, giving the parse stack, and drawing the chart each time a non-terminal constituent is added to the chart.