Thanks for posting this question, Evan! This is a great opportunity to clarify the purpose of including "weighted campus users" (which includes the number of on-campus residents and full-time & part-time students) in the OP-17 and OP-22.

OP-17 and OP-22 are focused on the reduction of waste and water use on campus, respectively. It would be unfair to compare the raw reduction between institutions of different sizes. For example, reducing annual waste generation by two tons would be a very different accomplishment for a small college, compared to a large research university. To make the point allocation more equitable for different types of institutions, these credits consider the number of “weighted campus users.” Effectively, the waste generated and the water used is normalized based on the number of people on campus. That is why these credits are asking for information about on-campus residents and full-time & part-time students.

Getting back to your question, the most important thing is that you use the same type of campus population figure (i.e. annual average for each population group or the fall figures reported to IPEDS) for the 2005 baseline year and the performance year. That said, if you choose to use the annual average, please use the average over the entire year. Remember that you can provide details, including specifics on your data, in the public notes section of each credit.

I hope this response is helpful. Please feel free to contact me directly or respond to this post if you have additional questions or comments.

Margot

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Margot Hutchins
STARS Reporting Coordinator
Association for the Advancement of Sustainability in Higher Education
margot.hutchins@aashe.org | 859-258-2551 ext. 122 | www.aashe.org

Hi Evan,

Great question. I would echo many of Margot's comments (especially as it specifically relates to STARS). As someone that has been doing intercampus and intra-campus data comparisons since the late 1980s, I would also suggest that it depends on the nature of your school. Most Common Data Set and IPEDS data was developed for traditional 2-semester residential schools. In many of those cases there is only a marginal difference between fall semester enrollment and spring semester enrollment.

However, schools that do not fit that model, either because they have trimesters, or a more active specialty summer program often have numbers that can be misleading in IPEDS or Common Data Set. As Margot mentioned, when comparing to your own baseline, I think consistency is important. When comparing between campuses, the footnotes of any comparison metric (whether recycling rate or per capita recycling) is often far more important than the metric itself.

Hope this helps.

-Roger