1. Demand-Driven Acquisition A Data-Driven Perspective

2. What is Demand-Driven Acquisition? Just-In-Case Collecting Just-In-Time Collecting Demand-Driven Acquisition

3. How DDA Works

4. Ten pages read in a single session Reading for ten minutes in a single session Downloading, copying, or printing any part of the title How DDA Works – Trigger Conditions

5. How long on average does it take for titles to trigger? Can we predict how much we’ll spend in the future? Are certain publisher’s titles being used more often than others? Are these triggered titles being used after they’ve been purchased?

6. DDA at the NCSU Libraries

8. Gathering the Data Internal (ILS) Data Sources Provider Data Sources Usable Information Holdings Data Trigger Data Internal Data Usage Statistics

9. Cleaning the Data

10. Joining the Data SELECT [Ebrary and PatronOwn].*, Ebrary.ebrary_DocID, Ebrary.[Purchase Date], Ebrary.Purchase_Total FROM Ebrary RIGHT JOIN [Ebrary and PatronOwn] ON Ebrary.ISBN_Print = [PatronOwn].ISBN OR Ebrary.ISBN_Print = [PatronOwn].ISBN2 OR Ebrary.ISBN_Print = [PatronOwn].ISBN3 OR Ebrary.ISBN_Print = [PatronOwn].ISBN4 OR Ebrary.ISBN_Print = [PatronOwn].ISBN5 OR Ebrary.ISBN_Print = [PatronOwn].ISBN6 OR Ebrary.ISBN_Print = [PatronOwn].ISBN7 OR Ebrary.ISBN_Print = [PatronOwn].ISBN8 OR Ebrary.ISBN_Print = [PatronOwn].ISBN9 OR Ebrary.ISBN_Print = [PatronOwn].ISBN10 OR Ebrary.ISBN_Print = [PatronOwn].ISBN11 OR Ebrary.ISBN_Print = [PatronOwn].ISBN12 OR Ebrary.ISBN_Print = [PatronOwn].ISBN13 OR Ebrary.ISBN_Print = [PatronOwn].ISBN14; Provider ISBN Internal ISBN

11. Gathering, Cleaning, and Joining – End Result Title ISBN(s) Provider Doc ID Creation Date Trigger Date (if applicable) LC Class Usage since trigger Publisher

14. Predicting Future Triggers Using the predictive calculation… (% of the Titles Added in Previous 12 Months Triggered) January 2015-December 2015 avg % triggered: 0.45% Predicted February 2016 triggered: 291 Actual February 2016 triggered: 305

15. Total DDA Pool and Total Triggered by LC Class

16. Percentage of Pool Triggered by LC Class

17. Average Use After Trigger by LC Class Average Use of DDA Titles per year: 89 section requests

18. Usage by LC Class 2010-2015 (section requests)

19. Time to Trigger by LC Class, in Days

20. DDA Pool by Publisher

21. Future Projects Comparison of DDA and ebook packages (Springer, Wiley, etc) Comparison of DDA and print usage Relationship between time to trigger and use after trigger Should items be pulled?

22. Thank you! Contact information: Shaun Bennett NCSU Libraries sbennet@ncsu.edu