Showing posts with label SBG. Show all posts
Showing posts with label SBG. Show all posts

Sorting Out the Summative: When Standards-Based Grading Meets the End of the Semester

Source: Wikipedia

Many teachers who choose to use standards-based grading eventually find themselves facing the reality of their school's grading policies and tradition: the expectation of final, summative grades that are reported as percentages and letters. So regardless how hard you try to focus on quality feedback instead of grades all semester long (for good reason), there comes a time when, for reasons probably beyond your control, you have to turn levels and descriptions of student understanding into numbers. This is SBG's "Monday Morning Problem" that doesn't always get addressed in theory. But this week is finals week for my basic statistics students, so for me the time has come to convert standards-based formative grades into a summative grade, including calculating final exam grades. Here I'll try to describe the two steps I'll take to calculate my students' grades: (a) conversion of their formative scores into a summative score and (b) scoring and inclusion of the final exam into their semester grades.

Formative to Summative
Besides giving students a lot of written and verbal feedback about where they should try to improve, I've been using the simplest of measures to record their performance on class objectives: either students (a) "get it," (b) "sort of get it," or (c) "dont' get it/haven't demonstrated it." You could think of these as "green light," "yellow light," and "red light," respectively. I've tried discerning more levels of understanding in a gradebook and it only seems to lead to confusion and indecision (both for me and students), so I'm sticking to three levels, as suggested in Her & Webb (2004). If I need more detail, I can always go back to the copies of the work students have submitted and the comments I've made.

The gradebook we have for class is pretty primitive and as far as I can tell it only accepts numbers, so I mark my three levels as either a 2, a 1, or a 0. It doesn't take much explaining to students that a 1 shouldn't be viewed as "out of two" and therefore worth 50%. I do tell them, though, that in order to receive credit for the course they should average a 1 across all objectives. In other words, you can't pass the class without an average of at least some understanding of every objective.

Around here and in many other places, 70% seems to be the low end of passing grades. (We're not messing with Ds.) So if a student with all 1s should get at least a 70%, and a student with all 2s maxes out at 100, and we choose a linear function between the two, the "conversion formula" to percentages is simply:

percentage = 30 * objective score average + 40

If you feel a little dirty at this point because you know you just reduced all the various skills, knowledge, and abilities of your students into a single number, I say join the club. If you didn't feel that way I wouldn't have expected you to be using standards-based grading to begin with.

A "No Surprises" Approach to Final Exam Grades
Designing a final exam is often tricky business. It can't possibly assess everything in the course, but we generally want it to include the major topics and themes for the class and be possible to complete in the time allowed. We also have to think about difficulty. Trust me, your students are!

Teachers want their finals to be challenging, but they don't want to have that sinking feeling as they grade the exams that maybe the test was too hard. For whatever reason, sometimes students perform poorly and averaging the final exam grade into their other grades will look like a disaster. But ask yourself: What am I more confident in, my careful judgments of students' ability as demonstrated over an entire semester, or a fleeting, one-time judgement of students' ability on a single assessment during the most stressful time of the year? If you're using standards-based grading, I already know how you'll answer that question. If not, consider this example: I have a student who I know can do stats. She's turned in good work. She's asked quality questions. We've had good discussions. But I also know she has seven final exams this week. I still think she'll do fine, but I'll understand if she's not at her best. And I need a grading system that reflects that understanding.

In order to free myself to still give challenging, yet reasonable, assessments, without risking any huge surprises when grades are calculated, I perform a little statistical magic that ensures that the distribution of final grades has the same center and spread of class grades before the final. I'm sure many of you try "curving" your exam scores some other way, such as letting the top score count as the total possible, or even having a pre-set distribution in mind of how many As, Bs, Cs, etc. you'll allow (which is not a good idea, generally, for reasons described by Krumboltz & Yeh, 1996). I prefer my method because it accounts for the distribution of grades, not just the top score, and the distribution is determined by the students, not arbitrarily by me. Allow me to demonstrate with a couple examples.

Suppose before the final the average percentage grade is 85 and the standard deviation of those grades is 10. Then I grade my final exams and find that the average final exam grade is 60 with a standard deviation of 18. Ouch. But don't worry -- statistics will come to our rescue.

Provided you know a little basic descriptive statistics, the conversion is simple. For each student's final exam score, find out how many standard deviations above or below the mean they scored on the final (their final exam z-score), and match that with the same number of standard deviations above or below the mean they'd fall on the pre-final grade distribution (their pre-final z-score). Consider the following students and the class and exam statistics above:

  • Suppose Student A scores a 51 on the final exam. That's 0.5 standard deviations below the mean. (51 - 60 = -9, and -9/18 = -0.5.) So where is 0.5 standard deviations below the mean on the pre-final distribution? If that mean is 85 and the SD is 10, then 0.5 standard deviations below the mean is 80. So I record an 80 for that student instead of a 51.
  • Suppose Student B scores a 75 on the final exam. That's about 0.83 standard deviations above the mean. (75 - 60 = 15, and 15/18 = 0.83.) So where is 0.83 standard deviations above the mean on the pre-final distribution? About 8.3% above an 85, so I record their exam grade as a 93.3.
  • Suppose Student C scores a 60 on the final exam. That's the same as the mean, so zero standard deviations above or below. That conversion is super-easy: their final exam grade is the mean of the pre-final mean, an 85.
For an example of how to set up a spreadsheet to do this, see https://docs.google.com/spreadsheet/ccc?key=0Anne5Z-jCkqhdDVtemkyaGhnRWFfclJoa0dIUVQ5RVE. I recommend making a copy of it for yourself and seeing what happens as you change values.

This is not a perfect system (and comments about its imperfections are welcome in the comments), but it does take away the element of surprise if the final exam happens to be way too easy or too difficult, or if other circumstances prevent grades from working out the way you'd expect. Yes, this is a norm-referenced system instead of a criterion-referenced system, meaning that the grades students earn on the final is measured largely as how they compare to their classmates and the class average. The good news is this: both the teacher and the students have an incentive before the final to master as many objectives as possible, and that is criterion-referenced. A high pre-final average helps everyone get a high final exam average, and a small pre-final standard deviation minimizes variability in final exam scores.

References

Her, T., & Webb, D. C. (2004). Retracing a path to assessing for understanding. In T. A. Romberg (Ed.), Standards-based mathematics assessment in middle school: Rethinking classroom practice (pp. 200-220). New York, NY: Teachers College Press.

Krumboltz, J. D., & Yeh, C. J. (1996). Competitive grading sabotages good teaching. Phi Delta Kappan, 78(4), 324-326. Retrieved from http://www.jstor.org/stable/20405782

2004-2006: My Adventures in Standards-Based Grading (And Why I Stopped)

(cc): NASA
Strap yourself into the wayback machine, boys and girls, because we're going back in time five whole years. Life was different then: the U.S. was engaged in wars overseas, unprecedented disaster had struck our Gulf Coast, and teachers struggled to adapt to an assessment-centric school culture. It was, like, totally different than things are now.

In 2003 I began my teaching career at a medium-sized high school in Southern Colorado. My first year, as it is for many teachers, wasn't much more than a fight for survival. I spent much of my second year learning how to become something other than the teachers who taught me, and part of that meant tinkering with my assessments. By my third year, I was ready to collaborate with the school's other four math teachers in a concerted effort to improve our assessment and grading practices. I'm not sure I knew what an ideal assessment and grading system should look like, but I knew I wanted something other than the traditional quiz/test, either-you-got-it-or-you-don't system.

I think there's a reason math teachers in particular get so heavily invested in assessment and grading. Numbers are our friends. We trust them. We can sort them, scale them, manipulate them, and summarize them in ways that reveal certain truths. I was determined - perhaps obsessed - with finding a grading system that was accurate and fair. To me "accurate" meant "students earn the grade they deserve" and "fair" meant "objective and unbiased." I think I really believed that if I could just find the right scales and weights, the math would solve my assessment problems. 

While I might have been facetious in my opening paragraph, things really were different five years ago. Not many teachers were bloggers, Twitter hadn't been invented, and you couldn't search for #sbg or #sbar hashtags. Sure, standards-based grading existed, but Guskey, Marzano, Wiggins, et. al. sure weren't knocking on my door to tell me about it. I didn't know about SBG and I don't think any of my colleagues or administrators knew about it, either. It's sad that so many good ideas in education struggle to find their way from theory to practice, but that's another story for another day. This story is about my attempts at standards-based grading, my successes, failures, and frustrations I had along the way, and why I reverted back to a traditional grading system.

2004-2005: SBG(ish)
During my first semester of teaching I spent many hours after school designing quizzes and tests, thinking, "This is part of being a first-year teacher. Once I write these tests I'll never have to do this again." HA! Not only did I not reuse any of those assessments, in six years of teaching I hardly reused any of my assessments. Every semester I had new problems, assessment designs, and grading systems that made my old ones look horribly obsolete. As I went into my second year of teaching, I already knew that I wasn't going to be satisfied with a traditional system.

Before I go any further, I want to make this clear: I'm not claiming that I somehow independently invented or discovered standards-based grading. I was making this up as I went along and, as you'll soon read, it didn't necessarily work all that well. I did manage to reorganize my gradebook around concepts and skills instead of dates or arbitrarily-titled ("Chapter 8 Test") assessments. But while that part looked like SBG, sometimes very little else did. In fact, I wouldn't be surprised if you read this and decide I wasn't doing SBG at all.

As I said, I started making SBG-like changes to start my second year, as you can see in this passage from my fall 2004 Algebra 1 syllabus:
Each unit in the text will have several key objectives that should be your focus during that unit. Your score for an objective will usually be established by your performance on a quiz or test and is based on my perception of your understanding. Objectives are graded on a scale of 5 to 10. Think of 10/10 as an A+, 9/10 an A-, 8/10 a B-, and so forth. Objectives not genuinely attempted will be given a zero. If you are dissatisfied with one or more of your objective scores, it is highly recommended that you see me for 1-on-1 help, preferably before or after school. Because the CPM philosophy is mastery over time, you can expect to be quizzed or tested over each objective multiple times, with each time representing an opportunity to raise your objective score.

I got off to a good start by focusing on objectives, but then quickly got bogged down by the point system. SBG isn't about accumulating points. Sure, you'll need a way to record student performance, but a well-implemented SBG system will be formative and focused on feedback, not a point system. By the way, if you ever want to drive yourself into an insane asylum, try a 5-to-10 point grading scale based on perceptions of student understanding. I nearly drove myself crazy, scoring, re-scoring, and re-re-scoring every bit of work out of fear that somebody's 7/10 actually showed the same understanding as a classmate's 8/10. I was far more concerned with ranking and sorting than feedback. Even worse, I would have students who scored 7/10 or 8/10 over and over, earning passing scores for objectives even though I'd never actually seen them get any right answers.

By the following spring (with a new set of classes, like a college schedule) I decided that it would be far better for students to get most problems all right instead of all problems mostly right, so my syllabus now said this:
IT'S ALL ABOUT THE ROADMAP. The objective roadmap is a detailed list of objectives that together make up everything you should learn in the course. The objectives are organized by unit, but each objective will be assessed separately. To pass an objective you need to get 80% or better on the objective test. If you fail an objective, you will have to retake and pass that objective test before moving on to any objectives in the next unit.

(Here are my roadmaps for Algebra 1, Algebra 2, and Business Math.)

Almost every objective test consisted of five problems, and if it wasn't right, it was wrong. I was so sick of agonizing over partial credit I got rid of it entirely. Objectives were added to students' grades on a schedule, and students who fell behind schedule got zeros on objectives they hadn't yet attempted. Zeros have rarely been known to play nice with the statistical mean, so a student who averages 80% on 80% of the objectives (with 0% on the others) is only going to get a 64%. It was setting a high standard, sure, but somehow I convinced myself that I was a one-man-army who could rid the world of grade inflation. Anyhow, I asked students to focus less on the gradebook and more on objective progress charts like this one:
(Those are student numbers on the left. Yes, this class only had 11 students.)
Still, if this was SBG, it was really, really bad SBG. Three major problems stand out. First, I was telling students that there were a bunch of objectives and any one of them could stop them dead in their tracks. (I think I relented on that one not far into the semester.) Second, I was still way too focused on points and percentages, not formative assessment. Third, a student who was "mostly right" on all five test problems got a zero in the gradebook, even if the cause was a small procedural mistake that he/she happened to repeat on all five problems. How's that for demotivation?

Amidst all the problems of this system, there emerged a brilliant, shining light, and her name was Tara. She gave me hope. She was part of a pretty special Algebra 2 class, and I think previous struggles in math had left her without much confidence. She barely spoke, and when she did it was very quiet, and quite often it was apologetic, like "I'm sorry to make you stay after school so I can retake a test." Tara understood the grading system and used it to her advantage, retaking test after test with study sessions in between. I remember a marathon session in the days before the final exam, when Tara was within sight of her goal of passing every objective. I think she stayed after school for five hours until her goal was finally met. Tara, if somehow you happen to read this, I hope you realize you weren't a burden, you were an inspiration. You did and still make me want to be a better teacher.

2005-2006: Professional Learning Communities (PLCs) and Common Assessments
I think every teacher knows that feeling when an administrator latches on to an idea from a conference or meeting they attended and then bring it home for their staff to use. Unfortunately, in a rural district like ours with scant resources, the promotion usually went like this:
This year we're going to implement [insert acronym or edujargon here]. I've talked to a lot of other principals who are doing it and think it's very effective. ["Effective" usually means "Since we didn't make AYP, again, I need to tell the state that we're trying something new. Again."] The principals I talked to sent their teachers to summer workshops and hired a coordinator to guide the implementation of [edujargon], but since we can't afford so much as a box a tissues for this school, I'll just tell you what I remember and we'll make the rest up as we go along.

For 2005-2006, administration was pushing Professional Learning Communities (PLCs) and common assessments. The math department PLC opted to tackle Algebra 1 in the first year, and we began by brainstorming a list of concepts we thought all Algebra 1 students should know. We shuffled our list into eight groups that aligned with our textbook and other materials, and finally scheduled eight test dates spaced evenly throughout the year.

Because of some of the success I experienced the previous year, we opted to grade each concept separately instead of amassing a single score for the whole test. Students who did poorly on a concept would be remediated and given an opportunity to retest until they showed proficiency with each concept. Perhaps more importantly, since all the Algebra 1 teachers were assessing the same objectives, using the same tests, all scored the same way, we now had a basis for comparing our students' performance, and that led to a sharing of tips and techniques for teaching particular skills. Unfortunately our time was limited so I never learned as much from my colleagues as I hoped, but there is certainly an advantage in using the same SGB system across teachers in a department, or even now across schools in our ever-connected world.

We had a schedule change that allowed freshmen to take Algebra 1 all year long. With about a month left in the school year, the progress chart for one of my classes looked like this:
You can detect a problem here: too many students started slacking at the end of the year!
Even though the system was working, it was showing new cracks. Students knew I had a finite (usually just 2 or 3) set of tests for each objective, and if they failed form A, they would carefully memorize their mistakes and the right answers, then pretty much fail form B on purpose so they could then take form A again. (Ugh!) Also, after two years of using this kind of system, I was growing tired of explaining and defending it to students, parents, and administrators. I enjoyed the extra time spent with students who came in after school, but it became increasingly hard to make up for the lost time. Lastly, the paperwork was a challenge - I had to have every form of every test ready at a moment's notice for students who needed to take or retake tests. Because I didn't have my own classroom, this meant hauling around a file box to three or more rooms each day in two different buildings.

One of my biggest dissatisfactions with SBG was the quality of the assessments I was using. During instruction my students worked in groups, delving into big problems in context, problems that required a combination of reasoning and the integration of multiple skills. Because I wanted to assess every skill in isolation, the tests I wrote were nothing like that. Too often they looked like this:
(What, I couldn't think of contexts for these?)

Goodbye, SBG
I was having another major problem at the end of the 2005-2006 school year: because of budget cuts, declining enrollment, and a shuffle of veteran teachers, I found myself out of a job. Even though I knew these to be the reasons, I was pretty hard on myself and thought if I had been a better teacher, then the district would have somehow found a way to keep me.

In the interview for my new job I talked about my assessment practices and quickly got the feeling that they wouldn't work in my new school. The school day was two hours longer and few students would be able to spend time after school. I still hadn't figured out how to measure skills in isolation while wanting students to tackle larger, more comprehensive tasks. I was now the only teacher in the district teaching any of my subjects, so I had no colleagues to work with on common assessments. Frustrated and not wanting to rock the boat, I figured a simple, traditional assessment and grading system would be the easiest and best way forward. I now know that I couldn't have been more wrong! In my bitterness and self-doubt I gave up the progress I had gained over two years of hard work.

If you take anything away from this post, I hope it's this: it's not 2005 anymore. You don't have to stumble around and make the mistakes I did. You don't have to work in isolation like I did. There's a great community of bloggers discussing standards-based and other grading practices, and I haven't met one yet that doesn't want to help their fellow teachers. You might not have access to the research, but some of us do and we enjoy sharing what we think about it. So please, whether you're new to SBG or have been doing it for years, share your experiences and don't hesitate to ask questions!