1. Digital Preservation Policies: Technical Considerations SAA Boston: 08-06-2004 Andrea Goethals, FCLA

2. 3 Suggestions  Consider your preservation policy a work in progress. Version and date your preservation policy.  Separate the more volatile components of your preservation policy from the more stable components.  Keep in mind the fact that computers can be time- savers. Automate, Automate, Automate.

3. SOME of the technical considerations  See your handout for the list…  Focus for today: file format decisions

4. File Format =  A usually-documented way a single file structures digital content and possibly metadata about that content.  File content := (internal metadata) * (content)+

5. 3 File Format Examples TIFF 6.0XML 1.0PLAIN TEXT

6. File Format Decisions in Policy  Which file formats to use for 'preservation copies’ (not access copies)  might digitize material to this format  might convert other digital formats to this format  might create a copy of other digital formats in this format  Requires value judgments on which formats make good preservation formats

7. You know a file format is a good preservation format when …  It accurately represents the real-world representation  Passes the Fidelity Test  It should be easy to interpret/copy/present/distribute in the future  Passes the Future Test

8. The Fidelity Test  Depends on the original ‘input’  Requirements of oral history vs. a symphony performance

9. The Future Test  Single (free?) publicly-avail. spec. from a reliable source  Short clear specification  Simple format  Includes technical metadata needed to interpret the content  Avoids codecs, etc. that require license fees, etc.  Relatively long history of use, well-supported  Completely self-sufficient, no external file dependencies  Doesn’t lose info during a copy-to this format  Not dependent on the original ‘input’

10. Fidelity Test != Future Test  A format that fails the “Fidelity Test” can ace the “Future Test”.  In the future you can perfectly support a poor representation of the input. (Bad)  A format that aces the “Fidelity Test” can fail the “Future Test”.  In the future you can't support a faithful representation of the input. (Bad)  A format that aces the “Fidelity Test” can ace the “Future Test”.  In the future you can perfectly support a faithful representation of the input. (Good)

11. Tiff 6.0 takes the Future Test  Single (free?) publicly-avail. spec. from a reliable source: Yes, freely available from Adobe's website  Short clear specification: Yes: 121 well-written pages  Simple format: Yes  Includes technical metadata needed to interpret the content: Yes, Image File Header and one or more Image File Directories  Avoids codecs, etc. that require license fees, etc. : Maybe, if you avoid certain codecs (ex: LZW in TIFF)

12. Tiff 6.0 takes the Future Test  Relatively long history of use, well-supported: Yes, since Summer 1992, good support  Completely self-sufficient, no external file dependencies: Yes  Doesn’t lose info during a copy-to this format: Yes if you avoid lossy compression (ex: JPEG in TIFF)  RESULT: Tiff 6.0 aces the Future Test as long as the codecs used in the Tiffs are restricted.

13. FCLA Action Plans