Task: Question Answering
Input (English): We decided to explore the remaining space for improvement on the CBT by testing humans on a random subset of 50 named entity and 50 common noun validation questions that the psr ensemble could not answer correctly. 
 Question: How do they show there is space for further improvement?
Output (English):  by testing humans on a random subset of 50 named entity and 50 common noun validation questions that the psr ensemble could not answer correctly