Greenhouse Effect Concept Inventory (GECI)

Developed by John Michael Keller

Purpose To assess pre- and post-instruction conceptual understanding of the greenhouse effect focusing on the physics of energy flow through Earth’s atmosphere.
Format Pre/post, Multiple-choice
Duration 15 min
Focus Astronomy Content knowledge (types of greenhouse gases, types of electromagnetic energy, energy equilibrium balance, greenhouse effect mechanisms, global warming vs. greenhouse effect)
Level Intro college
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Silver Validation
This is the second highest level of research validation, corresponding to at least 5 of the validation categories below.

Research Validation Summary

Based on Research Into:

  • Student thinking

Studied Using:

  • Student interviews
  • Expert review
  • Appropriate statistical analysis

Research Conducted:

  • At multiple institutions
  • By multiple research groups
  • Peer-reviewed publication

The multiple-choice questions on the GECI were developed based on student ideas about the greenhouse effect uncovered using open-ended surveys of students in introductory astronomy courses. Survey responses were coded, and several of the students’ central beliefs (models) about the greenhouse effect were identified. Several additional open-ended surveys were given to students to hone in on details of students’ beliefs. An initial multiple-choice version of the GECI was created, where the answer choices were those discussed by students in the open-ended surveys. After administering the multiple-choice assessment and revising several times, student interviews, and expert review, a final version of the GECI was created. This final version was administered to over 500 students at one institution and appropriate statistical analysis of reliability, difficulty and discrimination were conducted and reasonable values found. Overall, the GECI has been given to over 2500 students and results published in one dissertation.


  • Keller, John (2006). Part I. Development of a Concept Inventory Addressing Students’ Beliefs and Reasoning Difficulties Regarding the Greenhouse Effect, Part II. Distribution of Chlorine Measured by the Mars Odyssey Gamma Ray Spectrometer. Ph.D. dissertation, The University of Arizona.
  • Strickland, T. W. (2009). The Greenhouse Effect: Common Misconceptions and Effective Instruction. California Polytechnic State University- San Luis Obispo.

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Language Translator(s)  
Japanese Michi Ishimoto

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The latest version of the GECI, released in 2008, is vC.