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Electronic records Archives

Introduction to Preservation and Access Levels Concepts

(PAL v1.0)

(WBS #1.1.15)

for the

National archives and

Records administration

electronic records archives

program MANAGEMENT office

(NARA ERA PMO)

Final

December 5, 2003

Introduction to Preservation and Access Levels Concepts

[]{#__RefHeading___Toc58299556 .anchor}Signature Page

Program Director,

I recommend approval of the Introduction to Preservation and Access
Levels Concepts (PAL).

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Dyung Le, Date

ERA Program

Approved,

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

Kenneth Thibodeau, Date

ERA Program Director

[]{#__RefHeading___Toc58299557 .anchor}Document Change Control Sheet

**Document Title:** Introduction to Preservation and Access Levels
Concepts White Paper

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  **Date**   Filename/version \#    **Author**      **Revision Description**

  12/05/03   ERA.DC.PAL.1.0.DOC     Jon Valett/Ken  Final
                                    Thibodeau       

                                                    

                                                    

                                                    

                                                    

                                                    

                                                    

                                                    

                                                    

                                                    
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> TABLE OF CONTENTS

Signature Page [i](#__RefHeading___Toc58299556)

Document Change Control Sheet [ii](#__RefHeading___Toc58299557)

1.0 Purpose [1](#purpose)

1.1 Introduction [1](#introduction)

1.2 ERA Program Overview [2](#era-program-overview)

2.0 Document Assumptions [2](#document-assumptions)

3.0 Acronyms and Definitions [2](#acronyms-and-definitions)

4.0 Methods for Preservation [2](#methods-for-preservation)

5.0 Introduction to Persistent Archive Method (PAM)
[3](#introduction-to-persistent-archive-method-pam)

6.0 ERA Preservation Strategies [5](#era-preservation-strategies)

6.1 Preservation Strategies for Aggregates
[5](#preservation-strategies-for-aggregates)

6.2 Record Level Preservation Strategy
[6](#record-level-preservation-strategy)

7.0 Preservation and Access Levels (PAL)
[6](#preservation-and-access-levels-pal)

7.1 Basic Preservation and Access [7](#basic-preservation-and-access)

7.2 Enhanced Preservation and Access
[7](#enhanced-preservation-and-access)

7.3 Optimal Preservation and Access (PAM)
[8](#optimal-preservation-and-access-pam)

8.0 Relating Preservation Strategies to Disposition Agreements
[8](#relating-preservation-strategies-to-disposition-agreements)

9.0 Conclusion [9](#conclusion)

List of Tables

Table 3-1: Acronyms List [2](#__RefHeading___Toc58291282)

Introduction to Preservation and Access Levels Concepts

# Purpose

The purpose of the *Introduction to Preservation and Access Levels
Concepts (PAL)* paper is to clarify what is involved in the preservation
of electronic records as it relates to the Electronic Records Archive
(ERA). The paper does not completely define this concept, nor does it
attempt to fully articulate all its nuances. It provides background
information to the *ERA Concept of Operations (ConOps)* and *ERA*
*Requirements Document (RD)*.

## **Introduction**

Preserving electronic records serves the same fundamental *purpose* as
preserving any other type of record: to enable the records to continue
to provide evidence and information about the decisions, acts, and facts
described in the records with the same degree of reliability as when the
record was created. However, the *process* of preserving electronic
records is substantially different than the preservation of traditional,
non-electronic records. Traditional records are aptly termed "hard copy"
in that the information that the record contains is inscribed in a hard,
indissoluble manner on a physical medium, and the physical inscription
conveys the information the record is intended to provide. Therefore,
preservation traditionally focused on the physical object. However, an
electronic record is inscribed on a physical medium as a sequence of
binary values which must always be translated into a different form --
the form of a record -- in order to communicate the information the
record was meant to convey. Therefore, preserving an electronic record
requires maintaining the ability to reproduce the record from stored
data. While the preservation of paper record can be deemed successful if
the records remain physically intact in storage, the success of a
process of preserving an electronic record can only be verified by
translating the stored bits into the form of the record. It is the
result of this reproduction, not the stored bits, that literally **is**
the electronic record. If the wrong process is applied, or if the
process is not executed correctly, the result will not be an authentic
copy of the record. Over time, reproducing an electronic record is
challenging because the conventions for representing information in
digital form change along with hardware and software. Newer systems may
not be able to process older formats, or may do so incorrectly.

Given that both the purpose and the proof of preservation of electronic
records is access, National Archives and Records Administration's
(NARA's) goal is to preserve electronic records in a way which keeps all
of their essential properties -- as records -- intact, when enabling
users to access the records using state-of-the-art technology at any
time in the future. This means being able to reproduce electronic
records without dependence on specific hardware and software formats.

## ERA Program Overview 

ERA will be a comprehensive, systematic, and dynamic means for
preserving virtually any kind of electronic record, free from dependence
on any specific hardware or software. The ERA, when operational, will
make it easy for NARA customers to find records they want and easy for
NARA to deliver those records in formats suited to customers\' needs.

# Document Assumptions

The following assumptions were made during the development of this
document.

-   The PAL's intended audience is the ERA development contractor and
    the ERA Program Management Office (PMO).

-   The PAL is meant to provide guidance for the proposal phase of the
    ERA program. The concepts embodied in the PAL are expected to be
    further refined and explored during the Analysis and Design Phase of
    the ERA program.

# Acronyms and Definitions

**Table 3-1, Acronyms List**, contains a list of acronyms used herein.

  -----------------------------------------------------------------------
  **ACRONYM**       **DEFINITION**
  ----------------- -----------------------------------------------------
  ConOps            Concept of Operations

  COTS              Commercial Off the Shelf

  ERA               Electronic Records Archives

  GIS               Geographic Information System

  ISO               International Organization Standardization

  IT                Information Technology

  NARA              National Archives and Records Administration

  OAIS              Open Archival Information System

  PAL               Introduction to Preservation and Access Levels
                    Concepts

  PAM               Persistent Archives Method

  PMO               Program Management Office

  POP               Persistent Object Preservation

  RD                Requirements Document
  -----------------------------------------------------------------------

[]{#__RefHeading___Toc58291282 .anchor}Table 3-1: Acronyms List

# Methods for Preservation

There are various strategies for digital preservation, including:

-   Museum or Technology Preservation: maintaining the original hardware
    and software components in order to maintain the ability to
    reproduce the record

-   Format migration: converting all records from older to newer formats
    apace with the evolution of technology,

-   Emulation: providing environments that recreate the environment in
    which the records were created, and

-   Persistent Archives Method (PAM): keeping, and if necessary
    converting, records to a format that respects all its essential
    properties, but reduces or eliminates dependencies on specific
    hardware or software, enabling faithful reproduction over varieties
    and generations of technology.

The PAM technique (sometimes referred to as Persistent Object
Preservation (POP)) has one key difference from the others: it focuses
on preserving the specific properties of records, while the others focus
on solving the problem of technology obsolescence. However, the PAM
technique is aligned with a major direction in the evolution of
information technology: to enable business, government, education,
research, and other activities conducted over the Internet, the
information objects which are communicated in these activities must be
basically independent of the technology infrastructure. Because of this
mainstream direction, more and more products are appearing in the market
that can be used to implement a PAM strategy, whereas the other
techniques listed remain niche technologies. Thus, the PAM strategy
appears the best option for satisfying NARA's mission requirements for
preserving and providing access to electronic records.

# Introduction to Persistent Archive Method (PAM)

PAM rests on two (2) basic assumptions: (1) the essential properties of
a record can be specified, and (2) in many cases, a record may have
several different, but equally valid materializations. The second
assumption is implicit in many current applications. For example, many
organizations create records using computer applications, such as word
processing, but save these records printed on paper, and they may
disseminate them electronically in HTML or '.pdf' formats. Similarly, a
verbatim transcript of a hearing is commonly considered a reliable
record of that hearing, even though it may have been recorded originally
on an audio medium. Such practices presume that different
materializations of the same record are equivalent for the purposes for
which the records are created. PAM extends this presumption over time,
but adds a requirement for the explicit specification of the essential
properties of a record as a control which makes it possible to determine
if a reproduction is authentic. Generically, NARA defines the essential
properties of a record as including its content, structure, context, and
presentation. Identifying essential properties does not necessarily
entail that these properties cannot change, but that the variability of
any property must be specified and not change over time. For example,
one of the advantages of computer assisted design is that 3-dimensional
digital designs can be rotated and viewed from different angles. The
ability of a user to rotate the design defines a variability which must
be preserved. If the design were saved in a format which only supported
a static display, the result would be considered a version or extract of
the original design, not an authentic copy.

PAM has the characteristics of being comprehensive (it should work for a
wide variety of record types and digital formats), scalable to enormous
quantities, infrastructure independent, and flexible. The PAM method is
being developed within the context of an implementation of the
International Organization Standardization (ISO) standard for Open
Archival Information Systems (OAIS).

PAM is based on an object-oriented approach that is familiar to
Information Technology (IT) professionals, but has only recently been
applied to the work of archives and libraries. In the object-oriented
view, all objects are characterized as having specific attributes and
behaviors. Traditionally records have not been conceived as having
behaviors, but in a digital environment, it is necessary to specify what
operations or processes can be appropriately applied to any object, and
what the results of such processing should be. For a textual record, for
example, a required behavior is that its content must be presented in a
page layout. Every record has a behavior of occupying a specific
position in an original order imposed by the records creator, although
in a digital context the order and position are most likely to be
logical rather than physical. In the PAM approach, electronic documents,
which have both content and form or structure, are represented as
complex real-world objects having attributes and behaviors that must be
maintained. More complex cases, such as in a decision support or
Geographic Information System (GIS), the electronic records would be
represented as complex objects that include descriptions of behaviors
that explain how their subcomponents interact with other objects to form
the records. For example, a cartographic record displayed in a GIS may
include elements drawn from dozens of different layers in the system.
The behaviors of such a record include all of the operations needed to
retrieve the required data from the appropriate layers, defined in the
logical data model, and cause them to be displayed correctly in a map or
chart.

The context of a record is determined by its \"provenance,\" an archival
concept that can be defined loosely as the context in which a record was
created, and the "original order," an archival concept designating the
connections among records established by the records creator. An
electronic record\'s provenance and original order are represented by
defining groups of objects as logical collections. For example, in a
contemporary office e-mail system, each message would correspond to an
object with clearly-defined attributes (to, from, and date, among
others), while the group of all messages from an organization could be
represented as a collection, with the original order being the
organization of messages in user accounts. In an object-oriented
approach, a collection of objects can itself be represented as an
object.

Representing and encapsulating complex records from contemporary
information systems as objects and collections requires a flexible,
open, standardized, self-describing and extensible modeling language
that will preserve the content, context, and structure of records.
Persistently preserving records would entail encoding of record
attributes, behaviors, content, and structure into an encapsulated
object. This object would then represent all information required to
re-instantiate the record at a future time. A parallel approach would be
implemented to re-instantiate aggregates of records, such as files and
series. By expressing record properties in such formal models, PAM
reduces hardware and software characteristics. Software mediators will
enable future technologies to interpret the models and the metadata.

As more and more government transactions are conducted via e-Government,
electronic records will increasingly be created in formats that either
are, or can easily be converted to, persistent formats. In the near
future, however, NARA will need to ingest and preserve large quantities
of records in formats subject to rapid obsolescence. In order to
preserve them, eventually NARA will need to transform records to
persistent form using the open and standardized modeling/encoding
language. ERA will need to implement tools that will enable NARA to
transform records received in legacy formats into PAM formats. NARA will
need different transformation tools specifically designed for different
record and data types.

NARA will stipulate the attributes and behaviors of records that need to
be preserved, and define related metadata. This policy will govern the
transformation of records received in legacy formats and will also guide
agencies in creating records in formats that conform to these
specifications.

# ERA Preservation Strategies

The breadth, diversity and complexity of the electronic records
challenge require a comprehensive and coherent approach for preserving
and providing sustained access to authentic electronic records. This
overall approach specifies what will be done to preserve specific
classes of records and types of aggregates of records, as well as types
of digital data and files. The approach must include templates for
modeling the properties of records and aggregates, along with methods
for reproducing the records and arranging them properly relative to
other records in the same aggregate. These methods will vary depending
on the data types in which the records are encoded and the digital files
in which they are stored. A preservation strategy may be defined as a
specification of the methods which will be used to maintain, reproduce,
and/or arrange a class of electronic records or record aggregates. Given
the expectation of continuing change in information technology,
preservation strategies will need to evolve over time. Preservation
methods, then, include not only the methods for maintaining, reproducing
and arranging records, but also methods for migrating or transforming
the digital components of electronic records from one format to another.
Given the magnitude of the challenge NARA faces, there is a premium on
adopting preservation strategies which are consistent among themselves,
minimize the variety of methods NARA needs to employ at any given time,
and reduce the need for changing methods over time. The hierarchical
approach proposed for templates in the paper, "*Introduction to
Policies, Templates, and Requirements Concepts*," outlines a framework
for developing a coherent and manageable set of preservation strategies.

## Preservation Strategies for Aggregates

An archival aggregate of records is an ordered set. Aggregates may have
hierarchical levels. ERA will need to have a way to rebuild the
structure of any aggregate of electronic records, and to place the
records in the arrangement defined for that aggregate. The template for
an aggregate must specify its structure, enable members of the aggregate
to be identified, and determine how members are related to one another
within the arrangement defined for the aggregate. This template would
map to methods ERA would apply to identify an aggregate of records,
build the structure of the aggregate, identify the members of the
aggregate, and retrieve and place each member properly in the structure.
For example, for records organized according to a traditional file
classification plan, ERA should be able to establish a hierarchical
structure corresponding to the file plan, place any retrieved file in
its proper place in that structure, and place all the records that
belong in that file in their proper order.

In addition to the aggregates established by the records creator, NARA
may define sets of records to facilitate execution of its lifecycle
management functions. Such 'Lifecycle Management Sets' are established
by management decisions on how to meet generic, and usually ongoing,
requirements. They are usually independent of provenance. For example, a
policy to retain that all permanent electronic records in the formats in
which they were transferred to ERA, as well as any migrated or
persistent format, defines the Lifecycle Management Set of all files in
native formats. Whether a preservation strategy is needed for a given
Lifecycle Management Set depends on the nature of the set. The set of
all files in native formats is risk mitigation measure to enable
alternative migrations or transformations from the original received
files. To be effective it would require a preservation strategy which
specified a method for reading each of the formats included in the set.

## Record Level Preservation Strategy

An electronic record is encoded in at least one digital object. For
example, a textual document may be recorded in a word processing file,
and a transaction, such as a retail sale, might be recorded in a row or
tuple in a data base. But the word processing file might contain a
digital photograph. The photograph could not be displayed using only
word processing software. Similarly, viewing the sales transaction might
entail putting the data into an online form. The form might be in HTML.
In each of these cases, the electronic record would comprise two (2)
digital objects. A digital object which is needed to reproduce an
electronic record is called a digital component of that record. The
preservation strategy for all electronic records requires that all the
digital components of each record be identified and the format of each
component be specified. The strategy would stipulate the methods to be
used to assemble, organize and present the components in order to
reproduce the record.

# Preservation and Access Levels (PAL)

Preserving electronic records in a way which both satisfies records
management requirements and makes them relatively immune to changes in
information technology infrastructure is an ideal. Achieving this ideal
will be complex and costly. Therefore, NARA is developing a stratified
approach which provides continuing access to the records while providing
flexibility in managing preservation over time. This approach predicates
that there will be a minimal level of preservation and access services
provided for all permanent electronic records brought into the system,
and that this level may be increased over time, moving towards the goal
of persistent preservation described above. This section presents
examples of potential levels of preservation and access within ERA. The
preservation and access level for any record or set of records will be
specified in a Preservation and Access Plan developed at the time the
records are scheduled for transfer to ERA. Three (3) preservation and
access levels have been proposed. Alternative preservation and access
levels may be developed to accommodate changing technology or improved
preservation techniques.

## Basic Preservation and Access

At a basic preservation and access level, ERA will preserve all records
in their original format, encapsulating them with basic archival
information describing the record, including such items as date
received, agency, and series, as well as, the hardware and software
characteristics that will need to be known for later transformation. The
only guaranteed access service for records at this level will be the
delivery of the files in their original format. For some subset of these
records, such as for data types that only require software viewers, NARA
may also have tools that enable retrieval of the record in its native
format. This level will also include the ability to identify and
retrieve all the records in any aggregate of records. For some subset,
such as records arranged only according to a DOS directory path, it may
also be possible to instantiate the arrangement. Electronic records
received in legacy formats may not be converted to an enhanced or PAM
format for some time because of technical difficulties or costs of such
conversion. The basic services will be the only ones available for such
records.

Temporary and non-accessioned records that are only kept within ERA for
a few years may never move from this minimal level of preservation.

If the stored format becomes obsolete and there is (expected) demand for
access to the records, it may be necessary to migrate the records to a
current format, or convert them to a persistent format, to satisfy the
demand. The option between a current format and a persistent format
should be decided on the basis of relative costs and difficulty of the
transformation, and whether archival requirements for a persistent
format have been adequately defined. These options define two (2) other
Preservation and Access Levels.

## Enhanced Preservation and Access

There will undoubtedly be many cases where the file copy or software
viewers available at the basic level are not adequate, but where there
are also barriers preventing conversion to a persistent format. In such
cases, NARA would provide an enhancement over the basic preservation and
access service in order to satisfy requirements for continuing access.

The enhanced preservation and access level might include additional
external metadata indicating attributes defined in NARA standard
template for a given record type or aggregate (e.g., title, date,
issuing office or official for formal reports).

Enhanced service might be achieved by migrating records from obsolete
formats to newer ones for which better access software is available. For
example, a record might be converted from a proprietary format, which
required specific hardware or software, to a standard format which is
both defined in an open standard and has sufficient market penetration
and support to justify an assumption that it will remain possible to
access the record using Commercial Off the Shelf (COTS) products for
many years.

## Optimal Preservation and Access (PAM)

The optimal preservation and access level for archival records would
include retaining the records in the formats in which they were
received, and in a persistent version which satisfies requirements for
the preservation of authentic records and facilitates access using
advanced technologies. The persistent version is expected to be an
implementation of the Persistent Archives Method. The persistent version
would explicitly indicate the elements of content and structure,
presentation and behavior which have to be preserved. That is, it would
apply the NARA standard template for the record or aggregate type to the
stored digital components. The encapsulation or markup of the records
would conform to open, non-proprietary standards to achieve maximum
feasible independence from specific information technology
infrastructure.

Note that persistent versions could take different formats. For example,
for textual records received in a character-based format, where there
was a variety of record types, the content covered a variety of topics,
and NARA anticipated requirements for rich content searching, the
appropriate persistent format would involve semantic and syntactic
markup. But if textual documents were received in digital image format
and the anticipated demand was for copies of specific documents
presented with their original 'look and feel,' the appropriate
persistent version might be an image format encapsulated in metadata
which would support expected search strategies.

Conversion to persistent archival format will be more expensive than
simple encapsulation or migration to enhanced formats; however, neither
of the other approaches provides any assurance of permanent preservation
or accessibility. PAM will ensure that the record will be accessible for
the longest period of time. A PAM strategy, as described above, will
also reduce the technical variety that NARA must support over the long
term. Given the expectation of continuing change in IT, it is likely
that at some future time, NARA may decide to transform preserved records
to newer persistent formats, but such conversions are likely to be much
less frequent than format migrations. Moreover, NARA will probably have
greater flexibility in deciding when to execute the transformations.
While format migrations will be driven by the obsolescence of current
formats, transformations between persistent formats will likely be done
to take advantage of improved technologies. NARA would have the option
of performing such transformations opportunistically, such as when
records are retrieved in response to reference requests or when storage
subsystems are replaced as part of routine technology refreshment. Such
considerations should make the long-term costs of the PAM strategy less
expensive than alternatives.

# Relating Preservation Strategies to Disposition Agreements

A disposition agreement which provides for transfer of electronic
records to NARA entails requirements for preserving and providing access
to these records after transfer. How NARA will meet these requirements
should be set out in a Preservation and Access Plan for the records
covered by the agreement. The Preservation and Access Plan should
identify the types of records, record aggregates, and the data types of
their digital components. It should specify the application of the
current NARA preservation strategies for these types of objects.
However, given the great variation in the way electronic records are
created and retained, there may be no established preservation
strategies which are adequate or appropriate for the records covered by
an agreement. In such cases, the representative of the records creator,
the NARA appraiser and a NARA preservation specialist should work
together to develop a suitable Preservation and Access Plan.

# Conclusion

This paper has presented an introduction to the preservation of
electronic records in the context of ERA. It states the purpose of
preserving records, rather than digital artifacts, and describes how the
preservation process for electronic records extends through the
production of copies of those records. It sketches an idealized vision
of a Persistent Archives Method, but presents a multifaceted and
flexible approach to realizing that vision. It shows how that approach
can be integrated with the lifecycle management of records.