Refocus from 'who says' to 'what they have said' --- What if I rephrased the sentencer to read 'I believe that this improvement will be seen favourably', what is the presupposition? The negative should give you a hint: "I don't believe that this improvement ..." I don't know whether this improvement ..." You are absolutely justified in questioning somebody's certainty, but however assertive or toned down the speaker's opinion is, the presupposition remains that 'this improvement' exists. Focussing on the presupposition makes us question whether there is an improvement at all, not just whether the speaker is right in their evaluation.

Source author: Biljana Scott biscott@diplomacy.edu