In this task, you will be presented with a context from an academic paper and a question based on the context. You have to classify the questions into "Extractive", "Abstractive", or "Yes-no" questions. Extractive questions can be answered by concatenating extracts taken from a context into a summary while answering abstractive questions involves paraphrasing the context using novel sentences. Yes-no question is a question whose expected answer is one of two choices, one that affirms the question and one that denies the question. Typically, the choices are either yes or no.

Input: Consider Input: Recommendation diversity. As defined in BIBREF18 , we calculate recommendation diversity as the average dissimilarity of all pairs of tags in the list of recommended tags. 
 Question: how is diversity measured?

Output: Extractive


Input: Consider Input: The resulting dataset consists of 22,880 users, 41,094 blogs, and 561,003 posts. Table TABREF2 presents additional statistics of our dataset. 
 Question: How many users do they look at?

Output: Extractive


Input: Consider Input: We address the robustness problem on top of GE-FL BIBREF0 , a GE method which leverages labeled features as prior knowledge. 
 Question: What background knowledge do they leverage?


Output: Extractive