Digital Preservation Metadata The PREMIS Data Dictionary Angela

Digital Preservation Metadata - The PREMIS Data Dictionary Angela Dappert angela@dpconline. org

What is Digital Preservation Metadata? Metadata = data about data Digital Preservation Metadata = metadata that is essential to ensure long-term accessibility of digital resources 11/12/2021 2 timbusproject. net © 2011

Domain 11/12/2021 3 timbusproject. net © 2011

What Digital Preservation Metadata to store? n A best guess on the future n little experience validating the longevity of digital objects n uncertain future technical possibilities n uncertain future legal framework n Digital objects must be self-descriptive n Must be able to exist independently from the systems which were used to create them n XML (machine and human readable) 11/12/2021 4 timbusproject. net © 2011

The PREMIS Data Dictionary Information you need to know for preserving digital documents Preservation Metadata: Implementation Strategies 11/12/2021 5 timbusproject. net © 2011

The PREMIS Data Model includes n Entities: “things” relevant to digital preservation that are described by preservation metadata n n Relationships between Entities n Properties of Entities (semantic units) 11/12/2021 6 The process properties: context Object v Intellectual Entity v Representation v File v Bitstream n Event n Right n Agent Provenance information: logs, business motivations, preservation objectives, design decisions timbusproject. net © 2011

Activities n Data Dictionary (PREMIS 2. 1) n http: //www. loc. gov/standards/premis/v 2/premis-2 -1. pdf n PREMIS Implementors' Group Forum (pig@loc. gov) n email message to listserv@loc. gov subscribe pig your name 11/12/2021 7 timbusproject. net © 2011

Fore Example: Object Entity semantic units 1. 1 object Identifier Name 1. 8 environment 1. 8. 1 environment. Characteristic 1. 7 storage 1. 2 object Category 1. 8. 2 environment. Purpose 1. 8. 3 environment. Note 1. 8. 4 dependency 1. 8. 5 software 1. 3 preservation Level 1. 9 signature Information 1. 4 significant Properties 1. 8. 6 hardware 1. 5 object. Characteristics 1. 5. 1 composition. Level 1. 5. 2 fixity 1. 5. 3 size 1. 5. 4 format 1. 5. 5 creating. Application 1. 5. 6 inhibitors 1. 6 original 1. 10 relationship 1. 11 linking. Event. Identifier 1. 13 linking. Rights. Statement. Identifier 11/12/2021 8 timbusproject. net © 2011

Sample Data Dictionary Entry 9

Scope What PREMIS DD is: n Common data model for organizing/thinking about preservation metadata n Implementable n Standard for exchanging information packages between repositories n Technically neutral n Core metadata 11/12/2021 10 timbusproject. net © 2011

Scope What PREMIS DD is not: n Out-of-the-box solution n All needed metadata n Lifecycle management of objects outside repository n Rights management 11/12/2021 11 timbusproject. net © 2011

Why do we need new forms of preservation metadata? 12

Technology Dependence digital Complex environments … No direct access 13 • Not self-descriptive • Complex formats

Technology Dependence Metadata: n need for detailed rendering information n Software n Hardware n Other dependencies: schemas, style sheets, encodings, etc. n need format information 14

Complex Structures … § Metadata: need for structural descriptions Physical structural relationships • Embedded files • File sequence 11/12/2021 timbusproject. net © 2011 15

Complex Structures • Metadata: need for structural descriptions • Logical structural relationships … 16

Supporting New Features Metadata: Semantic Information for the designated community 17

Obsolescence Action: n Frequent, pre-emptive preservation actions (migration, emulation) Metadata: n Provenance metadata: n history of all actions performed on the resource n history of custodianship n Business rules guiding preservation actions 18 v events v changes and decisions v agents (decision maker + tools used) v dates

Obsolescence Action: n Preservation actions during copyright period Metadata: n Preservation action rights information 19

Obsolescence Action: n Preservation actions resulting in potential loss of object characteristics Metadata: n Significant characteristics = business requirement n Technical and content characteristics of objects before and after preservation actions 20

Mutability Intentional or accidental change Decay: rapid and potentially complete 21

Mutability Viability: the object is readable Action: Metadata: n Sound storage management practices, including climate control n Data carrier metadata n type of medium n Choice of resilient file formats n n Media refreshment (copying data from one storage device to another) its preservation characteristics n age of medium n date of recording n usage patterns 22

Mutability Fixity: the object is unchanged Action: Metadata: n Regularly compute checksums n Checksums, message digests (>=2) n Event creating them n Hash algorithms creating them n Date/Time n Originator 23

Mutability Integrity: the object is whole and unimpaired Action: Metadata: n format identification and validation n event information format identification and validation events (= provenance) n structural information: n all files are there n all files are named correctly n structural metadata 24

Mutability Authenticity: the object is what it purports to be Action: Metadata: n Procedural: n Provenance metadata n virus protection n Digital signatures n firewalls n Access rights n tight authentication n intrusion detection n immediate attention to security alerts n Technical: n Replication n digital signatures 25

Context Descriptions Metadata: need for context descriptions • Original source • Related items (e. g. migration source) • … 26

Preservation Pyramid (from Priscilla Caplan) 27