SME's and Instructors: The Good, and the Difference Between Them

I was talking with my friend Joseph about a training that he had in Puppet, and the instructor's assumptions when they started the class.  Now, before I start, let me tell you that Joseph was a trainer and instructor with Guru Labs, a well-respected source for Linux training.  He started relating to me the experience he had with the trainer, and how he reacted to the training process.  I immediately identified the trainer as a SME, or Subject Matter Expert.  This prompted a quick discussion on the differences between the Subject Matter Expert and the Instructor or Trainer. 

If you have been following my posts for a while, you know that I have a different definition of what a Trainer is, or rather what a trainer should be.  Trainers are those who not only know their subjects, but know how to convey the subject to the student without exceeding their cognitive load.  There are a lot of tricks to doing this that anyone can learn, but the real instructor can recognize and adjust to their student's cognitive capabilities. 

At the heart here is the cognitive load.  That is, the level a student can reach before they feel overwhelmed.  Some do so quickly, either because they are new to the subject or they have inhibited their learning somehow (no breakfast, poorly hydrated, medicated, distracted, etc.).  A great instructor can adjust the environment, terminology, and teaching methods to appeal to the student's learning ability. 

So where does the SME fit into this?  A poor SME can be easily identified by how they react to a question to which they do not know the answer:  they lie through their teeth.  They make something up that sounds plausible, and then teach it as though it were fact.

A good SME will do the research, though usually they do it during the training when they should be moving on in the lecture.  This means they keep the students on hold, often bored, while he tries to find the answer.  A bad instructor will do this as well.  Also, it's well worth noting that a good SME can become a good Instructor, with proper experience or training.

A good Instructor will place the question on hold (often after polling the students present to see if anyone has had a similar experience), and then will do the research after the lecture and while students are going through exercises.  He will then immediately come back when he has the answer to let everyone know what the answer was, and as a bonus point, tell them where the answer was found. 

There are a lot of other clues to telling a good instructor from a good SME, but this one is the one that came up in our discussions.  Does anyone else have a similar experience, or one they would like to share?