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The key research tools in PEN research are the PEN prototype questionnaires (available in multiple languages here) , the PEN Technical Guidelines, the list of codes, the PEN database for data entry, and various notes on data analysis and research methods to be developed as the project progresses.

Students and researchers not directly linked to PEN are welcome to use the questionnaire and guidelines in their own work and for non-commercial purposes. Due reference and acknowledgement should be made, using the following citations:

  • Center for International Forestry Research (CIFOR). 2007. PEN Prototype Questionnaire, version 4. Available at: Prototype

  • Center for International Forestry Research (CIFOR). 2007. PEN Technical Guidelines, version 4. Available at: Guidelines 

Comments to and suggestions for changes in the databases or manual can be sent to: