The idea of the Information Gap (or Collaborative crossword) is to have two copies of a puzzle, each partially answered. The goal is for students to pair up, and to come up with their own definitions for a word, and help each other finish the unfinished half.
Examples of different teachers and materials using this technique:
Because the clues are not presented in this style of puzzle, there is no need to fill at the clue section for each word.
There is no way to solve this puzzle type online.