We are revising the way we calculate student savings for the project to better reflect what we know about student textbook buying habits. Instead of reporting a single value for student savings, we are instead providing a range of student savings for British Columbia students as a result of a faculty adoption of an open textbook.

## How we used to calculate students savings

We have 2 categories of adoptions. A **Displacing Adoption** is an adoption of an open textbook that replaces a resource that students used to pay for. A **Supplementary Adoption** is an adoption where the open textbook is being used in the course, but is not replacing a commercial textbook (ie students are still paying for a textbook or course pack). To calculate student savings, we only use data from displacing adoptions at British Columbia post-secondary institutions as these are the adoptions that directly result in student savings.

When an instructor contacts us to tell us they are using an open textbook, we ask for the following information:

- Institution
- Number of students
- Number of sections the book is used in
- Course name
- Cost of textbook the open textbook is replacing

From this information, we multiply the cost of the textbook being replaced by the number of students using the open textbook to come up with total student savings for that particular adoption. We then add up all the self-reported displacing adoptions from all BC institutions and came up with the total student savings number.

## The problem

The problem with this method is twofold.

First, tracking adoptions of open textbooks is notoriously difficult. We try to remove as many potential barriers to adoption as possible and make the open textbooks in our collection truly open resources for anyone to adopt and use. To do this, we do not require or ask for any information from faculty who want to use our textbooks. Everyone is free to download and use them without informing us they are doing so. Because of this, all textbook adoption information we get is self reported by faculty who have chosen to share that information with us (and if you are using one of our textbooks, please let us know) and because adoption reporting is voluntary, we suspect we are missing adoptions happening at BC institutions by faculty who have not reported their adoption to us.

The second problem is that our original calculation assumes that every student purchased a new textbook, and we know this is not the case. Some are using lower cost options, like renting and purchasing their books used, and our original calculations did not take this into account.

## The change

Which is why we have decided to change our reporting to use a range of savings instead of a single value.

Our high end of the range will still be based on the total cost savings based on new textbook purchases. But the new low value is to better reflect the alternative buying options available for students. This low end value will be calculated based on an average cost of $100 per student per textbook. This $100 value is becoming more widely used in the open textbook community to represent students savings, and was derived by OpenStax College based on a formula that takes into account used textbook purchases and rental costs as well as new textbook costs. This number is also being used by the Tidewater Community College in their Textbook Zero program.

You can see the change in how we report student savings reflected on the home page of this site where (as of this posting date Feb. 18, 2015) the amount of money students in British Columbia have saved as a result of open textbook adoptions is between $470,400 and $706,221.

*Photo credit: Savings on Blackboard by Images Money used under CC-BY-SA 2.0 license. The image has been modified (cropped) and the cropped version on this page is released under a CC-BY-SA 2.0 license*