Mindstorm House 

This is a little example of why linear curricula and discover-based learning do not work well together.  


This is Papert's classic house problem. Getting the roof on the house properly requires turning the proper angle between the square and the triangle.  Mindstorms gave this as an example of debugging, but in the 1980s it migrated into assignments in math textbooks that included Logo as a means to teach students about angles and in some cases later in the curriculum about writing procedures (Blocks.)  Some books drag students through it, others ask the student to solve it.  When solving it with a polygon block, the curriculum assumes a right turning polygon.  This is a cultural bias!


But consider a student who for whatever reason stumbles on a left and right polygon, or has a smart friend, sibling or engineering parent, or invents it themselves.  Suddenly there is no need to calculate the angle.  



Does the student get an 'A'?  Is the student's solution 'correct' if the objective was to teach angles, and the assessment was to calculate the turn?  Is it an 'A' if they invented it, or an 'F' if they found it on the Internet? Is it a remix or plagiarism? Hard enough for a skilled human to evaluate, do you really want an autograder judging it.


So which of the two solutions in this project is 'correct' in turtlestitch.  I would say neither because that line between the house and the roof is traversed twice. Optimizing the two polygons results in six moves.  Knowing how to optimize code is a HUGE idea in CS.  Try it.  Insert you solutions in the comments.



Have Fun!