Changing the degree of comparison without changing the meaning refers to the translation of expressions or sentences from one form to other. For example, changing a sentence from Positive form of comparison to superlative form or Comparative form of comparison and vice versa. Superlative form is the highest of all. As example, Rohan is as strong as his brother. This sentence is in positive form. In Comparative it would be - Rohan is not stronger than his brother. Mumbai is bigger than most other cities in India- Comparative form. Mumbai is one of the biggest cities in India- Superlative Form. If you go through the examples, you'll see only the structure has changed, not the meaning. The meaning of the sentence is as same as the original sentence.