Seeing the Duck...Or the Rabbit

Imagine meeting someone who could only see this picture as a duck.  They cannot see the rabbit.  Your job is to get them to see the rabbit.  
That is what teaching really comes down to.  Getting someone to see something new or something old in a new way.
How do you do it?  I don't know.  
As an educator what I feel like I do know is this:
This task cannot be quantified.
This task cannot be achieved using the same method for everyone.
This task is not measurable as a learning outcome.
But, this task is the central function of good teaching.  
Measure what you want.  Create tests and teach to them.  Assess and assess and assess.
But, don't think what you're measuring is getting you any closer to seeing the rabbit if you can only see the duck yourself.

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