Monday, January 30, 2012

Grading Papers

Without exception, retired teachers I have spoken to agree that the best part of retirement is not having to grade papers, especially on Sunday night. And yet there was something very satisfying and rewarding about looking at student work in detail. Grading a student's paper was like spending a few minutes inside of that student's mind. It took a lot of time and it was hard, but carefully grading papers was an important part of the teaching and learning experience.

My last blog was about how grades influence the learning experience. This one is about how the details of arriving at one of those grades are equally important. Papers must be graded fairly. A graded paper should contribute to a child's education in a meaningful way, regardless of the grade attached to it. I would like to share some of my thoughts about the process of grading student work.

At the top of every paper I intend to grade is the sentence :

"You must show enough work so that I can reproduce your results."

I have found that this phrase solves a lot of practical problems about how much work a student needs to show. It also helps when the students solves a problem in an unexpected way. It allows a student to use technology intelligently as long as I am given enough information so that I can get the same result using the same technology. It enables me to effectivly evaluate the error a student has made and give the appropriate amount of credit for the work.

This leads to another aspect of grading a student's work that developed carefully over the thousands of problems I graded. I give points for correct mathematics. I do not take off points. When a student looks at the number of points earned for a particular problem, the student will see a +10, not a -2. The students got the 10 for doing several things correctly that would have lead to the correct answer. Unfortunately, the student made an arithmetic error when computing part of the answer and so did not earn the 2 points allotted for determining the correct answer. It should be noted that one consequence of this grading policy is that a bald answer without supporting work will get 2 of 12 possible points.

We are teaching mathematics. We are assessing the quality of mathematical reasoning a students is capable of. That means we need to see the process used to arrive at the solution, and it is the process we are evaluating. It is inappropriate and short-sighted to require the students to use the process we expect, but we cannot evaluate what we can't see. So, if a student uses a guess-and-check method, I need to see the guesses and the checks. If the student uses intuition and evaluation, I need to have the intuition explained, and I need to see the evaluation.

Consequently, it takes a long time to grade a set of tests. The effects, however, make it worth the effort. I have learned a lot of mathematics by following the work of a student who took an unexpected path. But more importantly, grading lots of papers teaches the grader what sort of misunderstandings students have, and that in turn enables the grader to try to find ways to eliminate thsoe errors next time around. At the very least, one learns to warn students about a mistake students often make on a particular kind of problem. At the most, the teacher can modify the problems used to teach the concept so the class will make the mistakes early on, exposing and hopefully eliminating the potential for those mistakes to occur.

Another consequence of grading this way is that the grader learns a lot about the particular habits of mind of the student. This information in turn is very helpful when the student or the parent wishes to know what can be done to improve. The teacher is aware of a lack of organization, or not checking work,or poor computation skills, or careless marking of a diagram or any of the other habits that interfere with success and can communicate those habits to the students and parent.

Comments to the student congratulating a clever move will have more impact than criticism about a bad move. A teacher can take the opportunity to point out specifically to a student what might have resolved the error. The feedback is up-close and personal and has impact.

But perhaps the most important aspect of grading papers this way is that it conveys a sense of value to students. It implicitly tells them that the important part of mathematical work is the process. They will get points for failed attempts if those attempts are appropriate and reasonable. They will get more points for a clever observation than for remembering a few steps from a previous problem. The students will learn that mathematics is about logical reasoning and making connections more than mathematics is about remembering rules and following them carefully. And that is a big deal.

Wednesday, January 11, 2012


Grades are the elephant in the room when it comes to learning and teaching. They are an ever-present part of the relationship between teacher and student in most educational situations. Grades can interfere with learning if students believe that no matter how hard they work, their grade will not improve, or if students believe that they can get an A without doing much work. Grades can destroy that partnership if students think the teacher is unfair. Grades consume a large percentage of a teachers time.

Perhaps the worst part is that frequently grades become the goal and overshadow learning. Teachers sometimes use grades to coerce students to comply. Teachers do things like not giving credit for math work done in pen, even if the work is exemplary. Students use grades as an excuse for not doing work. Students will not investigate a problem further bacause they know it will not be tested.

And yet, grades persist. I think they can play an important role in education. Students and parents need feedback about their accomplishments, they need advice about how to improve, and they benefit from legitimate praise and criticism.

Allow me to share two very personal experiences that are vivid memories of my grade school days. For two years in a row, I was told by the music teacher that I could not sing. (She was right.) I was then instructed to mouth the words as the other children sang. As I grew up, I realized that I love music, but I can't sing, so I don't try. I have been told by several people that anyone can learn to sing. I don't believe them, because I was told at a very young age that if I sang, it would interfere with the singing process in class. I can't do singing. The second experience happened in eighth grade when my social studies teacher was trying to explain inflation. I rasied my hand and asked a question about the consequences of inflation. He looked at me and said, "You must be really good at math." Fifty years later, I remember that moment in class; I have devoted my life's work to mathematics.

Both teachers were assessing my work. Neither assessment had anything to do with grades. My grades in school were never very good because I frequently didn't comply with the teacher's wishes about how to do the work (I really liked doing math with a pen, for example). But I did learn and so consider myself to have had a good education in spite of all those C grades.

When I started teaching, I had the good fortune to be in situations where I had the freedom to decide how grades were going to be given. I spent a lot of time thinking about it, tried many plans, and eventually hit on one or two that worked. I think my grading schemes helped me become a better teacher. I would like to share some of my thoughts about grades in the next few blogs.

I have always thought that in order to earn a good grade, a student should demonstrate knowledge of the subject and the ability to apply that knowledge in a variety of situations. That means that each assessment should include some routine exercises to see if the student has learned the basic material, problems right out of the book with different numbers. The students should also be expected to do problems similar to some of the really hard problems that we did in class. And the student who wishes to earn an A ought to demonstrate the ability to apply the information from the unit, as well as from the entire course studied so far, to a new situation. So, my tests are usually about 50% routine problems, 25% difficult problems that are similar to problems they have worked on , and 25% original problems. I give them one period to work on the problems unless they are legally entitled to more time. I carefully look at their work and give credit for correct mathematics relevent to the problem.

Solving a difficult problem takes time, and there is often a certain amount of luck involved. A promising approach may lead to a dead end through no fault of the problem solver, while an equally promising approach may work just right. If we intend to assess out students' success as problem-solvers, we must ask them to solve problems on tests, not just do exercises. That in turn influences how we associate a grade with work done.

I would like to know who decided that 95% was the benchmark for excellent work and what sort of work were they thinking of. Nothing I can think of that is reasonably difficult can be done correctly 95% of the time. The best baseball players that ever lived were successful at getting on base if they could get on base 40% of the time. Most players don't even come close, because hitting a baseball is very hard to do. A 30% success-rate is outstanding.

One of the national standards of excellence in the U.S., the Advanced Placement test, gives only five grades: 5,4,3,2, or 1. In order to get a 5, a student needs to get approximately 72% of the test correct. That level of excellence will often earn college credit for the course in question.

A score of 100 or more out of 150 is considered outstanding on the National Mathematics Exam offered by the Mathematical Association of America every year. That score qualifies a student to move to the next level of competition and often means that the student was in the top 1% of students taking the exam.

P.J reminded me about Dr. Paul Sally's rubric: "If you're getting 50%, you're doing well." Dr. Sally taught Honors Analysis at the University of Chicago. No one ever accused Dr. Sally of having low standards.

That brings me to another thought about grades. My first two years I computed grades two ways. I kept track of total points earned by students, and I also assigned a letter grade to each assessment and then used the letter grades to determine a final grade. It became apparent theat the letter grade method was far superior in two respects. First, students always seemed to have a feeling for where they were. Second and more important, the letter system was fairer, the letter system meant the grade was less influenced by a really bad test, and the letter system allowed me to assign points to problems without regard to making the total come out to a pre-specified number.

Another principle I followed without exception: Every problem was worth the same number of points. I didn't want students to have to worry about how much time to spend on this one or that one bacause one problem was worth more points than another. I did want my students to look the problems over and work the ones they were most confident about first. Since I established the cutoff points, this was a very good and fair policy.

The point is that the elephant is there, and it matters. Grades influence our effectiveness as teachers, and we must spend considerable time and effort working out systems that enhance our teaching, emphasize the things we think are important, inform parents and students about the quality of their work, and are even-handed and fair.

Next time I will share with you some specific things that worked for me. Until then, please reflect on the grading policy that you are using and how it alters your ability to teach mathematics. No matter what you think, it does make a difference.

More later.