I am not sure that my report on the inquiry lab conveyed the excitement that students felt in doing the lab. In making them responsible for the procedure, I created an "edginess" to the class that kept most students on their toes, much more than a "normal" lab. This was evident in all three classes (I only wrote about one).

That said, I don't think you will ever get a class where someone doesn't feel excluded for any number of social, emotional, or intellectual reasons. Students walk into class with their own (sometimes enormous) invisible baggage. Not much you can do about that.

One key to preventing student frustration (way more important than I realized at first) is the the understanding by students that they get to revise their procedures and try again. T&S and others knew they had a second chance. That makes a big difference in dealing with their frustration.

Another key (also not recognized by me at first) was the second-day class discussion about factors influencing the experiment. That discussion allowed students to listen to what others had done and adapt their procedure accordingly.