Poor, poor Sad Sack

Sometimes, there’s nothing like using a good story to teach a difficult to understand concept. In “The Story of Sad Sack, the Type II Error” NCSSM Instructor Floyd Bullard used an iPhone, an app called Stop Motion Studio Pro, and the power of creative storytelling to explain one of the more confusing topics covered in his AP Statistics class: differentiating the types of errors when testing a hypothesis. According to Bullard, “it’s no wonder students sometimes forget the difference between a Type I Error and a Type II Error in statistics. The terms are utterly non-descriptive.”

“The Story of Sad Sack, the Type II Error” is a short, stop-motion, animation meant to help students associate the four possible outcomes of hypothesis testing with memorable characters that have distinct “personalities”.

According to Bullard, “despite good contextual examples in textbooks, students will still incorrectly believe that Type I and Type II errors are sort of ‘mirror images’ of one another.” Several years ago Bullard suggested to his students that the four possible outcomes of a hypothesis test were more like completely different “personalities,” and that’s how the character of Sad Sack, the Type II Error was born.

Bullard hopes that students who watch “The Story of Sad Sack” will not only easily remember what the different terminologies mean, but will also have a richer understanding of what these errors “feel like”–the Type I Error is a “false alarm, or excitement over nothing, and the Type II Error is a pitiful, sad, failure to discover something real.”

The Story of Sad Sack, the Type II Error The Story of Sad Sack, the Type II Error: An Explanation View Additional Materials

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• August 02, 2016
• by Floyd Bullard ’87
• statistics ap statistics