First of all you will never see the word message mentioned in those languages you mentioned
Second the word , understood, says nothing about the nature of the problem to a beginner
Is it that the method does not exist ?
Or is it that method exists but message does not ?
Or is it that the method does something it should not ?
Or is the VM that has problem executing the method ?
"Message(method) does not exist" happens in C/Java/etc when we call a method."Message not understood by an object" happens in Smalltalk/Ruby when we send a message.I like this conceptual distinguishment��between calling a method and sending a message.Cheers,Alex