Hello, I'm just getting into Pharo, and am trying to do the example 'tutorial' UI programs in chapter 2 of The Spec UI Framework book. I have a special interest in end user GUI interfaces for programs. I enter the first example code as written and the methods are all accepted without errors. And yes, I did generate the accessors. However , on attempting to execute the code at the bottom of page 6 from the latest Spec UI Framework book, | ui | ui := CustomerSatisfaction newopenWithSpec. ui close. this error message appears, no UI image appears of course. "SubclassResponsibility:CustomerSatisfaction class had the subclass responsibility to implement #defaultSpec" ====== Not only don't I understand the message, but it implies I have to write something called #defaultSpec !, which is not mentioned in the tutorial. Any help appreciated, Yours, -- Cheers, Brett