The first few days of the DF course you are taught to talk with your hands on your ribs. When you inhale, you should expand your ribs/lungs as far as possible, to make sure your diaphragm has enough room to straighten out in a fluent motion. Then when you exhale and talk, you should use your hands to push your ribs inwards. This will cause your diaphragm to fold and go up in a fluent motion. You are taught to picture the movements of your diaphragm, first with two hands on your ribs without speaking and one hand on your ribs whenever you are speaking to help with the visualisation. And then a few days after that you can take your hand on your ribs away, while still focusing on what you have to do, speak and behave a little more natural and freely. It's very different from the MCguire, where DF is about visualizing the breathing movement of the diaphragm, it's not about the 'breathing' itself. In the DF method PWS speak fluently because of the picture in their mind, not because of the breathing, in my opinion. Then there are breathing excersises, 30 minutes each, which you have to do right after you wake up and right before you go to sleep. The purpose of those excersises is to train everything I have tried to explain above. Another purpose is, that when you wake up and do the breathing exercise, then it's a reminder to speak like this for the whole day (instead of returning back to the old habit). Also, there are 3 steps: 1. speaking while eyes closed while visualizing diaphragm movement. Always plan ahead a sentence, never speak slowly or mechanically, always speak at a normal pace and naturally. Always breathe in and breathe out before you speak where you stop the stutter thoughts (in my opinion, this is the only aspect in the technique that makes one speak fluently, this 'visualizing as distraction to stop focusing on stutter thoughts') 2. speaking while eyes open while visualizing diaphragm movement 3. speaking without visualizing, basically speak like a non-stutterer To conclude this, I have seen 60+ people use this DF technique and in my experience I've never seen anyone stutter with this technique. Only the big downside is that 'visualizing' takes 30 seconds sometimes, to say one sentence, which is not practical in a reallife situation in my opinion. The therapy is focused only on visualizing and 0% on the learning progress. Future studies could improve the learning progress such as learning from the (relationship of the) perception of the stutter thoughts and feelings