18-649 Project Participation Grades

Fall 2012

In past years there have been problems with team members slacking and other team members having to do extra work to compensate. Informal solutions have been relatively ineffective, so this year we are trying a more direct, formal incentive approach. This is an experimental policy and may be changed if doing so is in the best interest of accomplishing course objectives.

A fraction of student grades (10% of the course grade for Spring 2011) will be determined by participation in the project. In cases of severe slacking, as described below, students may also lose some or all of their project grade as well. The primary intent is to make sure that all team members contribute a fair share to the project. In particular, this is designed to avoid situations in which one team member gets a free ride from the other members' hard work. Comments and suggestions are welcome, although not all suggestions may be feasible to implement and it may take until next semester to make changes to avoid undue disruption.

Student Procedure:

Information is submitted by 9 PM on every Friday at: https://www.ece.cmu.edu/~ece649/progress/

Weekly student-reported information will remain private, and will only be disclosed beyond course staff as follows: (1) aggregate course hour data across enrolled students (look here for an example), and (2) indirectly in terms of its effect on aggregate scores as described below. In particular, other team members will not be directly informed of the exact contribution grades given and who gave them.

We encourage teams to attempt to set workloads to be evenly divided every week. Consider the data you report to us to be like voting -- you have no obligation to talk about what you submit and it is rude to ask others what they submitted.

Example: You spent 11 hours in the past week on the course including class meetings and so on. You think you contributed 34% of the technical value for the project this past week, and your other team members contributed 22% each (totalling 100%). Your weekly report would be: hours=11, and contribution rate might be {34, 23, 21, 22} (assuming your number is first in the set of numbers reported, and the other three are contribution rates your other team members assigned to you). You would not know the other numbers assigned, but you could reasonably infer they were lower based on the grade you are given for that week.

Grading Procedure:

Contribution Rate will be converted to a Contribution Grade using the following approach:

  1. The median Contribution Rate for each student shall be computed. This is the middle value out of the three rates for three-person teams, and the average of the two middle values for four-person teams. The median will similarly be computed using the typical definition of that function even if fewer values are available.
  2. Median rates will be renormalized so that the total for the group is 100. (For example, if median contribution rates are {20, 20, 21, 25} for four team members they will be rescaled to {23.3, 23.3, 24.4, 29.1} to total 100 across the team.)
  3. If a student does not submit weekly Contribution Rate information for any or all team members, the median computation will be performed using available information from other team members.
  4. The Median Contribution Rate will be converted to a Weekly Contribution Grade on a 100-point scale as follows:
    Four person groups:
    Median Contribution Rate
    (Integer 0..100)
    0 - 10 0%
    21 - 39 100%
    All other values min(110, Rate*4/100)
         Three person groups:
    Median Contribution Rate
    (Integer 0..100)
    0 - 10 0%
    28 - 38 100%
    All other values min(110, Rate*3/100)

    (Please note that these functions are intentionally designed to encourage regular contributions more or less equally spread among all team members. It avoids worrying about small differences on teams that are generally dividing the work equally. The band size for 100% grades may be adjusted depending upon actual experience.)
  5. At the end of the semester, the lowest one Weekly Contribution Grade will be discarded. All other Grades will be averaged to compute the Semester Contribution Grade on a 100-point scale.
  6. Multiple 0% contribution scores may result in escalating penalties as described in the exception handling section below.

Note that a 0% contribution score will be given for any project in which a student fails to fulfill the minimum requirements (e.g., a requirement that each student do some activities on at least one object). The student task list will be used to enforce this policy. Fradulent task lists will be dealt with severely.

Exception Handling:

Example Scenarios:

Example scenario: Students A, B, C, and D all do about the same amount of work every week, ranging from 22.5% to 27.5%. All students will get 10 out of 10 participation points.

Example scenario: Student A gets really sick and contributes nothing to the project for one week. That 0% participation grade is dropped and does not affect the number of participation points awarded.

Example scenario: Student A decides to take a road trip and does nothing on the project for one week. Then Student A gets sick and does nothing for the project on a second week. One of the 0% participation grades is dropped. The second 0% participation grade is retained. Student A disappears for another week, and for that week an additional 0% participation grade is entered and the student receives zero credit for that third week's project hand-in. (Student A could avoid the penalty by presenting Dean of Student or other valid excuses for all all three zero credit weeks.)

Example scenario: Students A, and B work hard on the project, with each contributing 30% of the work every week. Students C and D each contribute 20% every week. Students A and B will get 110% of the participation points (11 out of 10). Students C and D will get 80% of the participation points (8 out of 10). All students will receive the same project grade.

Example scenario: Students A, B, C, and D are on a project team. Students A, B, and C do 95% of the work every week. Student D does 5% of the work. Student D will get 0% for participation and will additionally only get 6.6% of the points for the team's project as well.

Example scenario: Student A thinks he did 90% of the work on the project, but students B, C, and D think he did 20%. Student A is awarded 20% for that week. If this is a recurring pattern, the instructor will likely intervene to improve team dynamics.

Example scenario: Student D hates Student A, and they both give each other 0% every week. Both 0% grades are dropped as part of the median computation. (And, very likely, the instructor will intervene to improve group dynamics.)

Last modified 26 Aug 2011