This exercise is a fun way to help clients understand acceptance.
1st part: The clinician gives a sheet of paper and a pen to the client and says "I'm going to ask you to write a sentence if you're okay". Then the clinician puts an obstacle (a piece of carton board, for ex) in front of client's eyes and says "Wait a minute, is this annoying you if I put this in front of your eyes? Would you prefer if I'd take it off? Well I'm sorry but I'm going to let it there though. However, as you said you prefer to see while you're writing, I allow you to do everything you want to try to see what you're writing. You can move your head, you can get up... Just do everything you can to see what you're writing. Is that okay? So let's go!"
Usually, after 20 to 30 seconds the client has still not written anything readable because s/he has been too occupied with trying to avoid the obstacle so we stop the first part of the exercise. The clinician then says "How was it? Was it difficult? Have you been able to write the sentence? Can we read it?" Obviously not.
2nd part: The clinician says "Well, I'm going to propose you another approach to help you write this sentence finally. I'm sorry but I'm going to let the carton in front of your eyes again. But this time, I propose you not to try to bypass the obstacle but to concentrate your efforts on writing. Maybe it won't be easy but just do your best to write the best you can so as we will be able to read the sentence."
Generally, the client very quickly writes a sentence that we are able to read and we can debrief then. A possibility is to ask the client to write some action linked to his/her value and to write on the carton the thing s/he tries to avoid (a painful thought for ex). Also: sometimes clients or participants in workshops get the thing during the first part of the exercise (i.e. s/he stops trying to avoid the obstacle and starts writing the sentence).
This is good too because it means they understand the approach by themselves. But it can be also interesting to encourage them to do as much as possible to see while writing so as to make them observe the difference between the two approaches.