I was hired by Professor Douglas Heckathorn of the Cornell University Sociology Department to create a cross platform, multilingual implementation of his novel approach to studying "hidden populations," known as Respondent Driven Sampling (RDS). This project is funded by a grant from the Bill and Melinda Gates Foundation, and the National AIDS Foundation.

      Hidden populations are those where members are reluctant to reveal their identity, due to participation in illegal or otherwise reproachable activities. For this reason, getting reliable sampling data to assist in research is a non-trivial task. A collection of "loose" metrics, including discerning physical traits, biometric measurements, and profiling data can be used in conjunction to provide a very reliable verification sytem. This is what the RDS Coupon Manager does.

      The software acts as an information collection, verification, and retrieval tool. Using JDBC, volunteer data is recorded and prepared for analysis using RDSAT, another program in Professor Heckathorn's suite. Respondents often arrive or call in to be paid for their referrals. In this case, the RDS Coupon Manager will retrieve the respondent's record, performing a biometric index calculation and using an average of z-scores to verify the respondents identity. Information such as who the respondent referred, and complete information about the respondent is also readily available to provide the highest level of data integrity.

      The RDS Coupon Manager is ready for production use, and is currently being translated into several languages for use in AIDS research facilites around the globe. For information concerning RDS, visit: