Tragedy of the Commons

Length: 3-5 Weeks
Grade Level: High School
Subject Areas: Math, Science


Key Concepts & Knowledge



How does a freely-used public resource degrade over time, with increased use, possible abuse and its eventual inability to keep up with demand? How can we improve things?

Students learn how to structure a multi-week interdisciplinary study, working collaboratively in small teams, structuring and maintaining their work schedule, collecting data, interviewing stakeholders, evaluating math models, and presenting results – written and oral.

Sequence of Project Activities

  • Prior to class, teacher reviews Video Teacher Guide and related background information.
  • In class, students experience the full BLOSSOMS video lesson Tragedy of the Commons.
  • Student teams are created (3 or 4 per team)
  • Problem identification and scoping
  • System observation and possible data collection
  • Examination of the 4 different BLOSSOMS math models for this problem, and discussion of an appropriate one for the team’s problem. Decision.
  • Interview stakeholders.
  • Collect results, summary and conclusions
  • Final oral presentation with submitted written report.

A Conversational Guide for the PBL Teacher

Read the guide here

Questions and Answers

Read them here