Problems with NL Interfaces

• Slow Typing: A formal query language might be faster for experienced users.

• Typing Errors: Most people are poor typists. A spelling corrector and line editor are essential.

• Complex Queries: Users may not be able to correctly state a query in English. ``All that glitters is not gold.''

• Responsive Answers:

  
  Q: How many students failed CS 381K
       in Summer 2018?
  A: 0
  

  Does this mean:
  1. Nobody failed.

  2. CS 381K was not offered in Summer 2018.

  3. There is no such course as CS 381K.

• Gaps: Is it possible to state the desired question?