Difficulties in NLU

NL has an extremely rich form and structure.

It is very ambiguous. There can be different levels of ambiguity −

      Lexical ambiguityIt is at very primitive level such as word-level.

      For example, treating the word “board” as noun or verb?

      Syntax Level ambiguityA sentence can be parsed in different ways.

      For example, “He lifted the beetle with red cap.” − Did he use cap to lift the beetle or he lifted a beetle that had red cap?

      Referential ambiguity Referring to something using pronouns. For example, Rima went to Gauri. She said, “I am tired.” − Exactly who is tired?

      One input can mean different meanings.

      Many inputs can mean the same thing.