I saw your question and thought I would share the following, in case it is helpful to you.....
Here at NHS Elect, we currently use the following simple questions, which we pose to coaching clients at the end of their coaching with us. We provide a QR code which takes them to the questions:
What did you gain from the coaching experience?:
How are you using these gains in your everyday work life?:
What would you say are your coach's strengths?:
No coach is perfect, so what would you say your coach does less well?
Rating: (scaling question 1 - 5)
No client is obligated to complete this, it is their choice. The feedback goes directly to the coach and is primarily used to provide them with potentially useful things to work on, in terms of their ongoing professional development (as a coach). We encourage them to reflect and discuss this feedback in supervision, which all of our coaches can access. Of course, a lot of the feedback is very positive, so that can be affirming and confidence inducing for the coach too.
These questions were developed by our faculty team, inspired by their own experiences working with coaches, the ILM Level 7 qualification they all undertake and no doubt some reading around the topic.
Hope this is helpful - good luck with your project.
We are confident that we have a very significant impact on the lives our clients, because people provide answers to the questions we pose to them (already shared). Our objective, as mentioned, is to provide feedback to our coaching team and in doing so, our clients are often very explicit about the value they derive from the coaching experience too. We don't have a requirement to statistically prove this and our interest is more in the value and impact created on a client-by-client basis. Our coaching practice has grown hugely through word of mouth and reputation, which is more important to us than any statistical analysis. I hope this makes sense?