Abstract: A computer-implemented method can include receiving a speech input representing a question, converting the speech input to a string of characters, and obtaining tokens each representing a potential word. The method can include determining one or more part-of-speech (POS) tags for each token and determining sequences of the POS tags for the tokens, each sequence of the POS tags including one POS tag per token. The method can include determining one or more parses for each sequence of the POS tags for the tokens and determining a most-likely parse and its corresponding sequence of the POS tags for the tokens to obtain a selected parse and a selected sequence of the POS tags for the tokens. The method can also include determining a most-likely answer to the question using the selected parse and the selected sequence of the POS tags for the tokens and outputting the most-likely answer.

Abstract: A computer-implemented method can include receiving a speech input representing a question, converting the speech input to a string of characters, and obtaining tokens each representing a potential word. The method can include determining one or more part-of-speech (POS) tags for each token and determining sequences of the POS tags for the tokens, each sequence of the POS tags including one POS tag per token. The method can include determining one or more parses for each sequence of the POS tags for the tokens and determining a most-likely parse and its corresponding sequence of the POS tags for the tokens to obtain a selected parse and a selected sequence of the POS tags for the tokens. The method can also include determining a most-likely answer to the question using the selected parse and the selected sequence of the POS tags for the tokens and outputting the most-likely answer.

Abstract: A dependency parsing method can include determining an index set of possible head-modifier dependencies for a sentence. The index set can include inner arcs and outer arcs, inners arcs representing possible dependency between words in the sentence separated by a distance less than or equal to a threshold and outer arcs representing possible dependency between words in the sentence separated by a distance greater than the threshold. The index set can be pruned to include: (i) each specific inner arc when a likelihood that the specific inner arc is appropriate is greater than a first threshold, and (ii) the outer arcs when a likelihood that there exists any possible outer arc that is appropriate is greater than the first threshold. The method can include further pruning the pruned index set based on a second parsing algorithm, and determining a most-likely parse for the sentence from the pruned index set.