Task: Question Answering
Input (English): We first measure the utility of various components in Logician to select the optimal model, and then compare this model to the state-of-the-art methods in four types of information extraction tasks: verb/preposition-based relation, nominal attribute, descriptive phrase and hyponymy relation. 
 Question: What open relation extraction tasks did they experiment on?
Output (English): verb/preposition-based relation, nominal attribute, descriptive phrase and hyponymy relation.