# To Curve or Not to Curve

A version of this post appeared in the print series of The Innovative Instructor.

Instructors choose grading schemes for a variety of reasons. Some may select a method that reflects the way they were assessed as students; others may follow the lead of a mentor or senior faculty member in their department. To curve or not to curve is a big question. Understanding the motivations behind and reasons for curving or not curving grades can help instructors select the most appropriate grading schemes for their courses.

Curving defines grades according to the distribution of student scores. Grades are determined after all student scores for the assignment or test are assigned. Often called norm-referenced grading, curving assigns grades to students based on their performance relative to the class as a whole. Criterion-referenced grading (i.e., not curving) assigns grades without this reference. The instructor determines the threshold for grades before the assignment is submitted or the test is taken. For example, a 92 could be defined as the base threshold for an A, regardless of how many students score above or below the threshold.

In addition to standardizing grades, norm-referenced grading can enable faculty to design more challenging assignments that differentiate top performers who score significantly above the mean. More challenging assignments can skew the grade distribution; norm-referenced grading can then minimize the impact on the majority of students whose scores will likely be lower.

A critique of curving grades is that some students, no matter how well they perform, will be assigned a lower grade than they feel they deserve. Shouldn’t all students have an equal chance to earn an A? For this reason, some instructors do not pre-determine the distribution of grades. The benefit of using a criterion-referenced grading scheme is that it minimizes the sense of competition among students because they are not competing for a limited number of A’s or B’s. Their absolute score, not relative performance, determines their grade.

There are multiple ways to curve grades.

I. The Bell Curve

Normalizes scores using a statistical technique to reshape the distribution into a bell curve. An instructor then assigns a grade (e.g., C+) to the middle (median) score and determines grade thresholds based on the distance of scores from this reference point. A spreadsheet application like Excel can be used to normalize scores. CER staff can assist instructors in normalizing scores.

II. Clumping

The instructor creates a distribution of the scores and identifies clusters of scores separated by breaks in the distribution, then uses these gaps as a threshold for assigning grades.

III. Quota Systems

Often used in law schools, the instructor pre-determines the number of students who can earn each grade. The instructor applies these quotas after rank ordering student scores.

Using a pre-determined scale, assessments are based on clearly defined learning objectives and grading rubrics so students know the instructor’s expectations for an A, B, C, etc.

During the 2011 Robert Resnick Lecture at Johns Hopkins, Carl Wieman, Nobel Laureate and Associate Director for Science at the President’s Office of Science and Technology, argued that most instructors are not trained to create valid assessments of student learning. Curving can be used as a tool to adjust grades on a poorly designed test, but consistent use of curving should not be a substitute for designing assessments that accurately assess what the instructor wants students to learn by the end of the course. CER staff are happy to talk to faculty about defining learning objectives and/or strategies for designing challenging and accurate student assessment instruments.

• Jacobson, N. (2001). A method for normalizing students’ scores when employing multiple gradersACM SIGCSE Bulletin. 33(4), 35-38.

Joe Champion’s Grading Transformation Spreadsheet. This spreadsheet automatically curves students’ scores after the instructor copies the scores into the spreadsheet and sets a variable defining the amount of curve.

Michael J. Reese, Associate Director
Center for Educational Resources

Image Sources: © Reid Sczerba, 2013.

# Making Group Projects Work

Instructors often find that student engagement increases when active learning strategies are implemented in the classroom. One strategy is to assign problem-based collaborative learning projects. Well-conceived group projects help students develop critical thinking skills, learn how to work in teams, and apply theories learned in the course to real-life situations, producing an appreciation for how the knowledge gained will be useful once the class is over. The end result is a richer learning experience for the students.

Students are more likely to appreciate and retain information when they see a correlation between course work and what they expect to experience as working professionals. Problem-based group projects typically require an array of cognitive skills, induce collaborative learning, and allow students to take ownership of the process. Moreover, students who learn to work in teams are better prepared for their future work environments.

Developing effective problem-based group projects requires assignments that reflect your course learning goals and incorporate course information, permit management of the student groups, and facilitate assessment of student progress. Advance planning and thoughtful strategies will go a long way towards ensuring successful implementation.

## I. Setting Student Expectations

• Weight the project fairly. You want your students to take the project seriously but you don’t want to weight the project so heavily that experimentation or risk-taking is stifled. Consider dividing the project into parts and grading each separately, so the team understands which aspects of the project went well and what needs improvement.
• Discuss student roles and what’s needed. Get the students thinking about what will be required of their team and how they can organize and manage the project.  Emphasize the importance of a team schedule. Discuss the qualities of a good teammate so that students begin the project with mutual respect.
• Start with small exercises as a warm up. Consider starting with a couple of smaller in-class team-based exercises so that students get used to working collaboratively

## II. Group generation methods

• Allowing self-selection of teams can create problems. Students like to choose friends as teammates. Personal issues then carry over into the project, friendships may suffer, or the members may take the project less seriously, resulting in poor group performance.
• Random selection is a reasonable alternative to student choice. This method is the fastest way to generate groups and more reflective of the real world. While random selection is convenient, consider ensuring diversity in each group to the extent possible.
• Skills based alignment is ideal for creating groups. Identifying students’ strengths and weaknesses through in-class exercises can help establish well-rounded teams. As a part of the preparation for the project, generate a list of the skills needed, have the students identify their strong and weak areas, then group the students accordingly.

## III. Getting each student to contribute

• Assign the students to roles. The difference between a dysfunctional group and a successful team lies in assigning roles. If students are assigned tasks with deadlines, they are more likely to take ownership and responsibility for completing their work as part of the team. Establishing roles can be a part of the group creation process. Avoid having students doing the same task for the entire length of the project. Instead, make the skill requirements for the team more conceptual. Use abstract concepts (Researcher or Synthesizer; Gatherer of Data or Analyzer of Data) so that broad expertise is required for each role.
• Require that a different student present the team’s progress for each report. Make sure that each student has an opportunity to participate in an in-class presentation. Presenting their work is a skill that all students will use in the future. As it involves an understanding of all the parts of the project, these presentations by each team member also help to ensure successful group collaboration.

## IV. Assessing the team/individual in and outside of class

• Have the students do evaluations. This can be done both during and after the project. Evaluations serve as reflective exercises for the students, allowing them to comment on how the process could be improved. Evaluations are particularly useful for gauging the team and individuals’ contributions for grading. Questions that require students to evaluate their own performance, the performance of each team member, and the team as a whole can provide insight into how the team functioned.
• Schedule time for team work in class. Scheduling group work outside of class is always a challenge for students. By allowing time during class for team work, you also will have an opportunity to monitor student progress. This is a great way to gauge whether the students are experiencing difficulties and provide an opportunity for questions, clarifications, or assistance with problems. Some of the best learning comes from spontaneous discussion in class, and peer-learning can be extremely effective when students are working together to solve problems.
• Ask for regular status updates. Starting class with a brief progress report from each team will bring up questions and concerns that can be addressed at once, eliminating redundancy and saving time.

## V. Build in time for reflection

• Reflection is key to learning from failure as well as success. Make sure you build in time for students to reflect on their progress. The best time to get the students to reflect on their experience is after the project during a debriefing discussion. Questions such as “What went well or not so well?” and “What would you do differently?” will enhance the opportunity for learning from their failures as well as their successes.

This post was adapted from The Innovative Instructor article series: http://www.cer.jhu.edu/ii/InnovInstruct-BP_MakingGroupProjectsWork.pdf

Pam Sheff,
Senior Lecturer, Center for Leadership Education, Johns Hopkins University
Pam Sheff is an award-winning writer and marketing communications consultant, with experience developing marketing, public relations and communications strategies for clients ranging from start-ups to large corporate, institutional and government organizations. Now a full-time lecturer in CLE, Pam has taught classes on business communications and entrepreneurship.

Leslie Kendrick,
Senior Lecturer, Center for Leadership Education, Johns Hopkins University
Leslie Kendrick has taught in the CLE program since 2002 and developed the five core marketing courses. She has 12 years of experience as a marketing practitioner. She has  worked for Harper & Row Publishers, Londontown Corporation, and Lippincott, Williams & Wilkins.

Image Source: © Reid Sczerba, 2012