So…I am on the phone with my son’s Assistant Principal for Curriculum and Instruction discussing getting him transferred to a different science teacher.
The Assistant Principal asked me why I wanted my son transferred. I mentioned that I thought that roughly 75 to 80% of the teacher’s grades were C, D, and Fs and that the teacher did not provide supports for all students. I continued, saying that his grading reflected his inability to get students to master the skills and content of the class.
The Assistant Principal’s response was this…
“The teacher’s grades are distributed normally. They don’t skew to the right or left.”
Which means a “C” is the most frequent grade. All things being equal, if grades are normally distributed, about 2% of the students will receive an A, 14% will get a B, 68% get Cs, 14% get Ds, and 2% of the class get an F. Essentially, 84% of the grades would be Cs, Ds, and Fs.
But that isn’t the interesting part…
…this is the interesting part.
Benjamin Bloom said many years ago,
“The normal curve is a distribution most appropriate to chance and random activity. Education is a purposeful activity and we seek to have students learn what we would teach. Therefore, if we are effective, the distribution of grades will be anything but a normal curve. In fact, a normal curve is evidence of our failure to teach” (Bloom, 1968, p. 2).
Think about that for a moment…
“…the normal curve is a distribution most appropriate to chance and random activity.” But, teaching is a purposeful activity. Therefore, the distribution of grades should NOT be normal. “In fact, a normal curve is evidence of our failure to teach.”
Which class would you want to be in? The blue class or red class?
More specifically, here is the distribution of biology grades for my son’s school.
Here is the normal distribution of grades for his teacher.
The school’s grades are not a normal curve which means, in general, the school is successful in teaching biology…except my son’s teacher has a normal distribution, which is evidence of his “failure to teach.”
“If we are effective in our instruction, the distribution of achievement should be very different from the normal curve. In fact, we may even insist that our educational efforts have been unsuccessful to the extent that the distribution of achievement approximates the normal distribution” (Bloom, 1968, p. 2).
We need to move to mastery learning where time is the variable and learning is constant and skew the curve to As and Bs.
Oh yeah…I was not allowed to move my son out of the biology teacher’s class. But thankfully his grades follow a normal distribution…sarcasm intended.
References:
Bloom, B. S. (1968). Learning for mastery. Evaluation Comment (UCLA-CSIEP), 1(2), 1-12.
Categories: Grades