Interpretive journeys and METS: Determining requirements for the effective management of complex digital objects in a National Park

The Metadata Options Appraisal

This paper deals with a Metadata Options Appraisal commissioned by the Loch Lomond and Trossachs National Park in Scotland in the context of a Europe‐wide project called MoPark Project (2004). Its remit is to look at three levels of the Park's metadata requirements: those specific to MoPark (level 1), those likely to arise if the scope of the MoPark work were extended (level 2, and those associated with the management of Park materials generally (level 3). However, since the MoPark requirements are the most complex, these have been the major focus of the work to date. The Appraisal was originally planned as a single initiative to be conducted in a number of steps (see Methodology), but a decision was taken on the basis of early findings to adopt a phased approach. This paper covers the work leading up to that decision – that is, it covers what is now Phase I of two‐phase appraisal, Phase I outcomes, and the reasons for the adoption of a phased approach.

MoPark and interpretive journeys

The aim of the MoPark project is to encourage green tourism in the Park by providing opportunities for sustainable travel and innovative interpretation. The interpretive facet is intended to help visitors understand and enjoy the Park's special qualities and will be delivered electronically via a variety of output devices, including personal digital assistants (PDAs), mobile phones, audio tours, and talking posts. In the case of PDAs, in particular, but perhaps also mobile phones, this will entail the creation of complex digital objects called Interpretive Journeys. These are multimedia‐based Park tours following marked out paths with a number of stops. Each stop is enhanced and interpreted for the visitor through an interactive programme consisting of still images, video and audio clips, animations, games, and text relevant to the flora, fauna, landscape formations and features, history, and culture represented at that point in the tour.

Interpretive journeys in other environments

In the context of the MoPark Project, an Interpretive Journey is typically a hand‐held electronic guide to a Park trail – whether it is a walk in the woods or a trip on a solar boat. However, the potential of this kind of digital multimedia presentation as a means of enhancing an individual's experience and understanding of a range of environments is clearly significant. Leisure and recreation environments – parks, museums, tourist‐trails, and similar – are probably the most likely areas of application. Education and other forms of training are another. This being so, the use of such packages seems likely to grow, which means that there is likely to be a increasing demand from a range of organisation‐types for information scientists who can advise on the issues covered in this paper – that is, on the problems raised by Interpretive Journeys and similar multimedia programmes, on the metadata required to adequately describe them, and on the design and operation of digital repository software to house and manage both.

Interpretive journeys as highly structured digital content

Interpretive Journeys (and other similar packages) are not simply collections of component digital objects with a common theme or a related set of such themes. They are pieces of highly structured digital content whose function, value, and meaning would be largely lost if their structure was lost – just as the function, value, and meaning of a book would be lost if it were cut up into paragraphs or sentences presented in randomised order. This means that the metadata required to manage them must, amongst other things, be able to capture and describe that structure, particularly if, as is envisaged in MoPark, there is (or may be) a requirement to disseminate these complex digital objects to other repositories, or to ensure their long‐term digital preservation. In the case of MoPark, for example, the metadata must be able to capture and describe structural elements such as the sequential and hierarchical nature of the journey, and the inter‐relationships between component digital objects at different sequential or hierarchical levels (for example, a map that can be called up at any journey stop and which itself has hierarchical levels in the shape of a ‘zoom in’ to a more detailed map, a key to the map, and so on).

Objectives of the Metadata Options Appraisal

The Appraisal has two objectives. The first is to determine the metadata requirements for the Park's proposed digital repository in the context of the ongoing use and long‐term management of these and other digital objects, looking at:

1. 1.

   MoPark project requirements (Level 1).

2. 2.

   Requirements if MoPark is extended to other topics and Park areas (Level 2).

3. 3.

   General requirements of the National Park beyond MoPark (Level 3).

This, of course, was a less than ideal circumstance in which to conduct the Appraisal. Following discussion, however, it became clear that it was unavoidable. Park staff required some guidance on metadata requirements if they were to specify their requirements for the Digital Asset Management System to the software designers and programmers, and the project schedule did not permit the long delay involved in waiting for the creation of the actual Interpretive Journeys. The appraiser was therefore faced with a requirement to deal with the situation, ideal or not – a real world circumstance which led to the proposal for the phased approach described below, and one which may well be encountered in other organisations as the digital revolution gathers pace.

METS

The Metadata Encoding and Transmission Standard (METS) is a schema developed following ground breaking work at the University of California Digital Library in the context of the Making of America II project (Cundiff, 2004; National Information Standards Organization, 2004; Coalition for Networked Information, 2003). Maintained by the Library of Congress (Library of Congress, 2004a), it has the support of the influential Digital Library Federation, and is designed to be used with a range of “extension schemas” such as MODS, MIX, MARCXML and TextMD (Cundiff, 2004; Library of Congress (2004b, c); Ockerbloom et al., 2004; Tennant, 2003a). In use in, or recommended by, a growing range of initiatives (Cundiff, 2004; Chandler, 2002; Guenther and McCallum, 2003; Institute of Museum and Library Services, 2001; Niu, 2002; Proffitt, 2004; Semple, 2004; Staples et al., 2003; Stehno, 2003; Tennant, 2003a), METS is also an integral part of at least one digital library management package (Staples et al., 2003) and was at the time of the work reportedly being considered for future use in MIT's widely‐implemented DSpace software (Smith et al., 2003).

MPEG‐21

MPEG‐21 is a Moving Picture Expert Group standard (International Organisation for Standardisation, 2002), expected to be a preferred approach in the commercial sector (Coalition for Networked Information, 2003). It was found to be less developed than METS (Coalition for Networked Information, 2003; Ockerbloom et al., 2004) and to be in use in one repository (Bekaert (2003, 2004)).

IMS‐CP

IMS‐CP, the IMS content packaging standard (IMS Global Learning Consortium Inc., 2004), is designed for use in the learning community, a community that MoPark will at least look to interoperate with. IMS‐CP is in use in various projects (Australian Flexible Learning Framework, 2004a, b, c; Coalition for Networked Information, 2003, p19), and is recognised as the learning community's alternative to METS and MPEG‐21 (Coalition for Networked Information, 2003; Ockerbloom et al., 2004). SCORM (Advanced Distributed Learning, 2004), another learning community solution also based on IMS specifications (Coalition for Networked Information, 2003) is also in use (Lubas, 2004). However, by the time it was identified as a possible candidate, it had already been agreed that the proposed future MoPark connection with the learning community was a relatively weak one and that there was no need to assess SCORM as one of the options.

Metadata and effective management of the digital repository

From the start, it was recognised that the underlying aim in conducting the Appraisal was to determine the requirement for the effective management of the proposed digital repository and the digital materials it would contain. The metadata requirements of any system are primarily related to function. In order to determine the metadata requirements for MoPark and for the National Park, therefore, it was first necessary to determine the needs in respect of handling or managing digital information and information products; that is, to determine which things needed to be done to, or, with what information and information products, by or for whom, in what circumstances (when, how, where), and for what purpose (why) in order to meet the management and service requirements of the system (National Information Standards Organization, 2004; Haynes, 2004; Farb and Riggio, 2004). It was also necessary to consider other issues affecting decisions on approaches to metadata: resources available for implementation and ongoing management, existing constraints in terms of the existence of legacy metadata repositories and legacy systems used by organisational partners, the need to interoperate with services outwith the group of organisational partners, and so on (Coalition for Networked Information, 2003, p. 23). Key requirements of a successful study were therefore an examination of representative examples of the various kinds of digital objects that would have to be managed and in‐depth discussions with Park staff on the management issues the various types of object would entail.

Initial methodology

A methodology for conducting the Appraisal was agreed in the early stages of discussions on project requirements. This consisted of the following steps:

1. 1.

   Participation in an initial briefing session with the client group and suppliers.

2. 2.

   An initial analysis of the outcomes, followed by an in‐depth consultation with project leaders on information needs, the amount and level of cataloguing required, the types of digital object likely to be stored and presented, the likely modes of presentation of these within interpretative journeys, and any requirements to access distributed information sources and integrate with other repositories, either now or in future.

3. 3.

   An in‐depth examination – via the literature and online examinations of sites – of a range of internal project and Park documents on issues relating to, or having an impact on, metadata needs.

4. 4.

   The creation of an outline, but detailed, sketch of the scope and complexity of the likely general needs of the project and the National Park in respect of metadata for digital objects.

5. 5.

   An examination of prominent global digital library initiatives and the metadata issues and solutions adopted by them.

6. 6.

   The identification of a digital object metadata framework sufficiently complex and flexible to meet the needs of the MoPark project and the National Park.

7. 7.

   The identification of a range of areas and issues requiring further investigation before the detailed metadata requirements of the project and the Park could be specified.

8. 8.

   The creation of a set of detailed questions that had to be answered – primarily by Park staff in discussion with the appraiser – in order to draw out and agree the detailed requirement.

9. 9.

   A specification of the detailed requirement

10. 10.

    The drawing up of recommendations on associated issues such as staffing and training requirements, costs, and the metadata management facilities required in the DAMS.

The need for a phased approach

In the event, the methodology had to be adjusted to take account of the information that emerged from the early part of the study. By the completion of step 4 of the process described above, two things were clear. First, that there was sufficient detail available from initial discussions with key MoPark and Park personnel (step 1), from follow‐up discussions with project leaders (step 2), and from project and Park documentation (step 3), to enable, both the general needs of the project and Park in respect of digital object metadata (steps 4‐6), and the further work needed to draw out the full requirement (steps 6‐8), to be specified in the timescale originally envisaged for this work. Second, that specifying the need in detail (step 9), together with associated staffing and training needs and detailed DAMS requirements (step 10), would be more difficult. It would require, at minimum, further work with actual examples of the complex digital objects (Interpretive Journeys) likely to form the primary elements of the Level 1 and 2 requirements, more experience amongst project and Park personnel of the issues and problems associated with managing complex digital objects, and an in‐depth survey of the likely range of other digital objects, their usage, and their life‐cycles.

Since the original assumption made by MoPark had been that the metadata requirement might be specified prior to the creation of the initial Interpretive Journeys and their use in the field, it was necessary to agree an adjusted methodology with project staff. This entailed adopting a phased approach to the completion of the Appraisal, with Phase I setting out, both a general framework within which the full requirement could be met, and the elements of the follow‐up phase, and Phase II stretching out over the full lifetime of the project (three years) and gradually specifying the detailed requirement as actual Interpretive Journeys emerged and were field‐tested, and as staff familiarity with these objects and understanding of the management issues they entailed, grew. This paper, of necessity, reports only on the outcomes of Phase I of this process. The outcomes of Phase II will be reported at a later date.

Interpretive journeys

The primary need is to deal with Interpretive Journeys. These are complex digital objects comprising coherent aggregates of a range of simpler constituent digital objects in a variety of formats. They will require a metadata framework that encompasses:

1. 1.

   Descriptive metadata (e.g. a MARC record) for both the aggregate object and the constituent objects.

2. 2.

   Administrative metadata for both – including technical detail on format and use characteristics, intellectual property rights information, descriptive and administrative metadata on the analogue source of the digital object, digital provenance metadata.

3. 3.

   Metadata on the files encompassed by the aggregate object.

4. 4.

   Metadata on the hierarchical structure of the digital object and on hyperlinks between levels (structural metadata).

5. 5.

   Metadata on executable programs required to run some of the constituent digital objects.

User‐type specific variations

User‐type specific variations are an issue. It is envisaged that different types of Park visitor will be presented with different versions of each Interpretive Journey and that these versions will themselves vary according to visitor choice of, for example, preferred terrain, and mode of transport. It is not clear at this stage whether each journey will be one single aggregate object or many similar, but different, aggregates. Either way, the metadata framework will have to be sufficiently flexible to cope with the inter‐relationships involved and the complex management issues entailed.

Output‐device‐specific variations

The issues described in the two points above are further complicated by the fact that different presentations of the various Interpretive Journeys are likely to be required for a range of different output modes (PDAs, web‐sites, mobile phones, and others).

Workflow control

Workflow control during the digital object management process is needed to ensure that accuracy, legal, metadata quality, and other requirements are met. The creation and management of Interpretive Journeys is likely to involve a range of Park personnel with different skills and expertise and this will have implications in respect of the need for a range of record statuses and the ability to monitor staff involvement in upkeep and creation in the metadata. Issues like information currency, accuracy, authority, access rights, metadata quality, and so on will make such involvement necessary and make workflow control and associated metadata needs essential elements of a working system

Format variations

Initial discussions suggest that the constituent digital objects that will make up the detail of the Interpretive Journeys are likely to be in a wide range of formats, including (but not necessarily limited to), textual materials, audio material, video materials, still images, animated sequences, 3D animations, 3D and 2D maps, interactive packages of various kinds. Any framework will have to be able to deal with the metadata requirements associated with each.

GPS issues

Special software will be needed to handle some of the constituent digital objects involved in an Interpretive Journey and it will have to be possible to specify this in the metadata framework. Included in this requirement is the need to obtain and respond to GPS data and to interact with an external GIS database system and repository.

Referencing descriptive metadata

It is likely that the descriptive metadata required for the aggregates and the constituent objects will in some cases be held on external systems (e.g. maps metadata and, possibly, MARC or Dublin Core metadata). In other cases, it may need to be embedded in the record for the object itself. The metadata framework will have to be able to handle either or both situations

Flexibility

The range and nature of digital objects likely to be managed when the needs of the Park as a whole are taken into account is at present unknown in detail. The framework adopted must therefore be flexible and wide‐ranging to enable it to cope with future requirements

Digital preservation

There will, in time, be a need to preserve some or all of the digital objects in the repository, so the metadata framework adopted must be able to deal with this likelihood.

Mapping to different metadata standards; XML output

A need to present or otherwise disseminate the metadata in various forms and various formats for different purposes in different situations is envisaged. Possible requirements in this respect include the need to interoperate with Library, Museum and (possibly) Archive community systems in Scotland1, to exchange data with other Parks or project partners in other countries, to meet the requirements of e‐GIF, the e‐Government Interoperability Framework (Broadley, 2004; Cabinet Office, Office of the e‐Envoy, 2004a) and, in particular, e‐GMS the e‐Government Metadata Schema (Cabinet Office, Office of the e‐Envoy, 2004b). It would be wise to allow for the use of a variety of standards, of mapping to different standards, and output in various formats. Either storing the metadata in XML (W3C, 2004) format or permitting its export and import in XML is advisable. Adopting national and international standards where possible is also advisable.

Other elements of the framework

In addition to the proposal to adopt METS as the basis for the framework for Phase II, two further recommendations were made on the basis of the analysis of general requirements itemised above.

1. 1.

   That the framework should assume the adoption, where possible and appropriate, of national and international standards relevant to the field. For example, in respect of descriptive metadata, it is sensible to investigate whether the use of Library of Congress Subject Headings (LCSH) on the one hand, and of the Dewey Decimal Classification (DDC) system on the other, provide the best basis for subject description and classification of MoPark and Park digital materials. A good deal of work is going on as regards interoperability in Scotland (Dunsire and Macgregor, 2003; Law et al., 2002; Nicholson and Macgregor, 2003) and this has recognised the significance of the HILT project, which has DDC and LCSH as key schemes (Nicholson, 2003; Shiri et al., 2004).

2. 2.

   The framework should allow for and facilitate cooperation with other key players with similar needs and interests to harmonise approaches and ensure interoperability beyond Park systems. An obvious partner in this area is the Scottish Cultural Portal Project (Winch, 2003), which has similar aims in a number of areas and an overlap in terms of client groups served. An example of possible cooperation here would be in the area of subject terminology. Even if LCSH were used as the basis of MoPark subject description, it is likely that it would have to be adapted and important that adaptations be harmonised with those made by other Scottish players. This and other related matters should be explored during Phase II, at which time other possible partners may also be identified. For example, it would be sensible to determine whether there is a need to work with other bodies engaged in providing digital learning materials to schools.

Phase II

As will be evident, the METS‐based framework proposed above provides a suitable framework within which to meet the metadata requirements of MoPark and the Park. As indicated earlier, however, there are problems in identifying the detailed requirement at this point in project development – problems that cannot be readily resolved through discussion and analysis as yet. Moving forward will require – at minimum – further work with actual examples of the complex digital objects (Interpretive Journeys) likely to form the primary elements of the Level 1 and 2 requirements, more experience amongst project and Park personnel of the issues and problems associated with managing complex digital objects, and an in‐depth survey of the likely range of other digital objects, their usage, and their life‐cycles.

A phased approach to determining the detailed requirements as regards metadata, metadata standards, and metadata management is therefore both necessary and sensible. This approach has been discussed and agreed with the project leaders and will be reported in a later paper.