Foreword

A curator's primary duty is to account for the collections in his or her care. Accounting for collections is essential not only for their care and preservation but also their safety, security and accessibility. There is little point in collecting if the collection that results is inaccessible. Thus collections are "catalogued" to varying degrees of detail in order to ensure both a simple inventory is held and, hopefully, that use can be made of the knowledge the individual object brings to the collection as a whole. The Royal Air Force Museum has rich and diverse collections. Most obviously, perhaps, we have the largest collection of aircraft in any single museum in the UK. However, our art, archive, photographic and other collections are also extensive. We are also a 'young' museum and we have suffered the same 'growing pains' as others in the past. These have been many and varied but an enthusiasm for collecting without the resources to properly document those collections is a common error of immature museums. Thus as we moved towards our silver jubilee in the mid-1990's it was clear that a special effort was needed to address the deficiencies inherited from our hard-pressed predecessors.

Our first task was to bring in relevant expertise to steer us through the minefield of modern data management. We decided, at the outset, that we wished to take a pragmatic and business-like approach to what we initially dubbed the "Documentation & Data Management Project" so we found an expert from the private sector. Our expert consultant, Tim Thorne was joined by one of our curators on secondment, Gordon Leith. These two set about the task of scoping our project and travelled extensively at home and abroad to discover best practice, problems and pitfalls of the task we had set ourselves. The help and co-operation received from the museum community was a key to the successful implementation of our subsequent Collections Management System. However, a considerable amount of work, over a three year period, was carried out before a software solution was chosen or any data entry could start. This work involved all members of the Museum's curatorial team and quite a number of other young people recruited specially to take on the task of ensuring the basic building blocks of controlled terminology were in place from the outset. The whole project was, and continues to be, overseen by a Project Board which I have been privileged to chair. We are indebted to those staff, past and present, whose critical involvement in the project made them members of the Board. We are also grateful for the participation of non-executive members from the IT Departments of Royal Insurance plc and BAe Systems plc who gave us invaluable help and support both through their respective organisations and their personal experience.

We now have a fully functional Collections Management System which is available via our Wide Area Network to staff at our three remote sites. The system is open architecture and multi-functional which will allow us to open access to it generally in due course whilst at the same time remain at the leading edge of technology.

The success of our system could not have been possible had we not made the critical decision to defer software selection and procurement until we had developed a comprehensive thesaurus. The original brief to our expert consultant was that we did not want to invent or prototype anything. We felt that, as a young museum, others must have trodden a well-worn path before us. We were wrong in the critical area of controlling terminology. No other museum in the World had developed terminology control to the level we required to properly complete a Collections Management System for aircraft and related collections. Thus we faced the task of compiling this extensive work which is of course an evolving and ever-growing entity. I am immensely proud of the work carried out by all those involved in this ground-breaking contribution to knowledge in our particular area of the museum sector. This Volume is but a part of that work, but it illustrates the dedication and skill employed by the key curators of the Royal Air Force Museum. They have been led, from the start, by the Museum's Senior Keeper Richard Simpson who with our Keeper of Visual Arts, Andrew Cormack still keep an ever watchful eye on the overall terminology control employed by us. This is the result of our labours in describing only aircraft and, in due course, it is our intention to publish the other strands of the complete suite of thesauri which made up our total terminology control package. Only pressure of work on other developments in the RAF Museum causes us to publish our work in phases but we are committed to sharing this resource we have created with the wider museum community.

I commend this work to you in the hope that, as it is implemented in other institutions, you will understand the great care, skill and effort which has been employed in its creation. It is in itself, and when combined with its yet to be published sisters, a great contribution to knowledge which I am sure will be appreciated by present as well as future generations.

Dr Michael A Fopp
Director General

Introduction

What is a thesaurus?

A thesaurus is a list of terms that describe objects or concepts that are sorted into a hierarchical order establishing relationships between the terms. They are in a sense a catalogue of information and are similar in structure to a family tree.

To ensure consistency when terms are added they are constructed according to defined rules/guidelines. The terms within the thesaurus are grouped together into meaningful relationships. The relationship of a term is illustrated through its position in the vertical arrangement of the hierarchy.

Why use a thesaurus?

A thesaurus permits data to be entered using standardised terminology and information to be retrieved efficiently. A thesaurus is dynamic and can be constantly developed through the addition or amendment of terms and the re-structuring of the hierarchies and relationships. Some of these terms can have explanatory notes, referred to as Scope Notes.

Thesaurus Development

The Royal Air Force (RAF) Museum was formed in 1965 and opened to the public on the site of the old Hendon aerodrome in 1972. The collections of the RAF Museum have over time been organised in different ways but currently consist of six major collections located at three separate sites (Royal Air Force Museum, Hendon; Royal Air Force Museum, Cosford and the Royal Air Force Museum Reserve Collection, Stafford):

• Aircraft & Exhibits
• Library
• Archive
• Fine Art
• Photograph
• Film, Video & Audio

Documentation & Data Management

All records, throughout the various collections, were held on manual systems for the first 25 years. Each department operated in isolation and undertook its own documentation and record keeping. The systems in place provided a permanent record of the material held by the Museum and varying degrees of access to the information about items within each collection but were not consistent. Only the Library had any subject indexing. During the period 1970 to 1993 a Library card index had evolved that was the first Museum system to make use of a thesaurus.

By 1993 it was clear that the advances in technology provided a major opportunity to replace the time consuming and cumbersome manual records with a central electronic documentation and information management system. The use of a museum wide system spanning all collections was considered vital to provide the most comprehensive access to the institution's holdings and reduce the dependence on specialist curatorial knowledge of the collection which would inevitably diminish with time.

The Museum decided to establish the Documentation and Data Management (DDM) Project. The first task undertaken by the new project team was to conduct a survey of existing departmental collections and record systems. This survey in 1993 established that only 27% of the Museum's holdings had been accessioned and could be accounted for through the various paper records. The primary goals of the new DDM Project were therefore to improve accountability, access and accuracy in respect of that 27% and establish a system which would ensure all future material brought on charge would have detailed and accurate documentation in a consistent form.

The survey also confirmed that there was no complete uniformity in terminology used to define or describe objects within the various collections. This had to change. Consistency would be vital if the electronic database was to be effective.

Development of the Thesaurus

The procurement of an electronic collections management system provided the opportunity to address consistency in the indexing and retrieval of information about objects within the Museum. The dangers and limitations of uncontrolled terminology were highlighted from visits to other institutions. If indexers do not exercise control with their use of terms it will ultimately be difficult for those trying to retrieve objects to use the index. The database would not be fully exploited and the Museum would see a low rate of return for its investment. The decision was taken to develop Terminology Control Instruments (TCIs) before procuring an electronic collections management system. This would aid those required to develop the structure of the index of objects. A Terminology Working Group (TWG) was established to enable discussion, policy decisions and development to be controlled jointly by senior curators and data management professionals. Large amounts of time and intellectual resources were put into developing these TCIs.

Research by the team found that no thesaurus existed that covered all areas of relevance to the Museum's collection. To begin from scratch would have been an immense task and was ill-advised, considering the Museum's finite resources. A decision was made to base the thesaurus upon the Library's subject headings list of approximately 40,000 terms. This list would also be used to index objects from other departments.

The capture of this data was carried out using Optical Character Recognition (OCR) tools and word processors. The subject headings list was initially divided up into sections to help users decide what section a subject term should come from. It soon became apparent that a more hierarchical structure to this list would be required and as a result it was divided into subject areas.

Although developed in some depth in the Library Subject Heading List, the area of Object Naming clearly needed a significant amount of time and effort to expand and develop it to meet the needs of the DDM. Members of staff seconded to the project team created a much larger and more comprehensive Object-Naming Thesaurus (ONT) guided by the TCIs.

For all thesauri co-ordinated terms such as those using Subject & Object Naming were divided up. Indexing and retrieval would be done using a combination of the different authorities. For example, Wreck of Hawker Hurricane Mk. I would be divided into the Concept of Aircraft Wrecks and the Object Name of Hawker Hurricane Mk. I.

The result of this work was the development of a number of TCIs or thesauri for differing areas rather than one thesaurus divided into segments, these are:

• Person/Organisation
• OCTARA (Object, Classification, Titling and Referencing Authority)
• Place
• Event
• Built Environment
• Concept
• Operational Area
• Material

OCTARA (Object, Classification, Titling and Referencing Authority)

The OCTARA arose from the merger of two existing authorities: the Object Names Thesaurus (ONT) and the Object Titling and Referencing Authority (OTARA) which had been created at an earlier stage in the development of terminology control.

Three sections have been constructed within the OCTARA:

Classification
The OCTARA provides a Classification for each and every object in the Museum's six Collections. This provides a broad class group for each object. It allows all artefacts of a like nature to be classified and for all relevant information to be retrieved in any system search. For example, Avro Lancaster Mk. I R5868 from the Aircraft and Exhibits Collection is classified as an Aircraft; a search using this term Aircraft would retrieve information about all aircraft in the collection.

General Subject Referencing (GSR)
This Section evolved to provide a subject reference tool which could be used for OCTARA work where the reference was of a non-specific nature or general in form. The structure mirrors that of the Specific Names and References Authority which it compliments.

For example, "Spitfires over the Arakan" by Norman Franks has a GSR reference to Supermarine Spitfire as the book does not deal with the individual marks of Spitfire but rather the operation of all versions of the aircraft in the Far East during the Arakan operations.

Specific Names and References (SNR)
This Authority provides names for all those objects which require subject referencing and naming and also where particular references are required for items from other collections, e.g. paintings depicting aircraft, books about radio sets and films of vehicles.

Thesaurus construction software was used in its construction. The Library Subject Headings Thesaurus did provide some references to object names but in some cases this was insufficient. For instance, all references to all the marks of a Supermarine Spitfire were listed as just Spitfire requiring the user to consult numerous sources to locate material on a specific mark. It was concluded that this type of index must be broken down to be an effective indexing and retrieval tool. For example,

Supermarine Spitfire

• Supermarine Spitfire Mk. I
• Supermarine Spitfire Mk. II
• Supermarine Spitfire Mk. III etc

The OCTARA forms a source of subject headings in addition to being the source for object naming. It is the aircraft Specific Names and References part of this thesaurus that is the subject of this publication.

The indexing and retrieval processes are applied to all collections in the Museum, with Aircraft & Exhibits making additional use of the OCTARA for object naming in addition to subject entries.

Since 1994 the TWG, chaired by the Keeper of Aircraft & Exhibits, has set out to achieve consistency in terminology across the Museum. The Group has met regularly to steer the overall terminology programme and, in particular, to develop and refine the terminology strategy. It still continues this work to this day although with a wider remit beyond just terminology control.

The summary above probably does not do justice to the many years of enthusiastic work by dedicated staff of the Museum to developing a flexible, practicable and comprehensive index of terms relating to the Museum's collections. The advantage with doing so much groundwork is that it is has saved time during the capture of object data and undoubtedly increased accuracy and retrieval.

Thesaurus Overview

Scope

The aircraft section of the OCTARA presented in this document contains all the aircraft that the Museum has references to within its collection. It is therefore not an exhaustive list of all aircraft that have ever existed.

For this thesaurus the definition of aircraft relates to heavier-than-air flying machines, with the exclusion of balloons, airships, kites, UAVs (Unmanned Aerial Vehicles), and various types of projectiles, such as missiles and rockets.

Structure and Organisation

The aircraft thesaurus is sorted alphabetically in order of manufacturer. Each narrower term under a broader term is prefixed with the manufacturer's name followed by the name and mark of the aircraft.

Terminology

The following is mostly extracted from the RAF Museum's Database Creation Strategy which defines the policies and strategy in current use.

With the exception of foreign proper names, the preferred form of a term is an English word. Whichever form is used for the main term the opposite form is presented as a non-preferred term.

Terms selected for authorities reflect traditional RAF Museum usage and RAF Museum expert opinion and terminology has been preferred before all other sources. Terms will be nouns or noun phrases. Adjectives and adverbs are not allowed in isolation as indexing terms. Terms will not contain initial articles (e.g. 'the' or 'a') unless they are part of a proper name, and therefore likely to be included in searches (e.g. The Aviation Corporation).

Term spelling is in natural language form. Each word of a term will have an upper case for the first letter followed by lower case letters. American spelling is only used where the term is strictly American and has no British literary warrant.

Trade marks are not acknowledged by any symbol or other addition to a name. Trade names have been permitted for indexing where they are the most likely term to be sought. Where equivalent common names are more widely used than the trade name the common name is preferred. Trade names are preferred before technically correct but infrequently used technical names.

Terminology Control

All terms added to the hierarchy are flagged as Candidate Terms, indicated by system generated <C> before the term name. Whilst terms have this status they will appear in the correct position in the hierarchy and are available for indexing and retrieval. The terminology analysts of the Museum will make a decision as to whether to accept or reject the term. If accepted the flag is changed to Approved. If rejected the term is removed from the object records it has been used in and an alternative is put in its place.

Terminology Definitions

Hierarchy
In essence, hierarchies are lists of terms that relate the terms above and below each other and in which this relationship can be shown by the vertical position of the term in the structure and the degree to which it is indented. Hierarchies have a top term, often known as a 'parent' term, from which a number of 'child' terms descend. These 'child' terms may in turn have 'children' of their own and the sequence can continue through as many 'generations' as are appropriate. The top term of a hierarchy is quite general and the further down the hierarchy one progresses the more specific are the terms that appear.

Broader Term - a term that encompasses the meaning of all terms underneath it.

Narrower Term - a term that sits under a broader term, only the lowest narrower terms are used for indexing.

Related Term - a term that is an alternative to another term and may be more relevant to either indexing or retrieval.

Use Instead - points a user from the current term (the non-preferred term) to another term (the preferred term). Only preferred terms are used for indexing.

Used For - points a user from the current term (the preferred term) to another term (the non-preferred term). Only preferred terms are used for indexing.

Retrieve but do not Use flag - this flag means the term is retrievable within the hierarchy but cannot be used for indexing, this flag usually applies to all terms except the narrowest of terms used for indexing. Flagged terms are used in retrieval when searching for objects as, when selected, all usable terms that are related to it in the hierarchy can be used.

Other

Facet Indicators
These are terms found in brackets and where used express the nature of a sub-division of a broader term i.e. Aircraft

• (By Manufacturer A-D)

This indicates that this section of the aircraft authority only contains aircraft terms for manufacturers whose name begins with the letter A, B, C or D.

{See Scope Note}
A scope note is used to clarify the specialist meaning of certain terms, whether it be an indexing term, a facet indicator or a Hierarchy title that may not be immediately apparent to the general user.

A scope note defines the precise meaning of the term in the context in which it is used in an Authority, i.e. to restrict or expand the application of a term if our usage of it differs from normal usage in natural language; to distinguish between terms that have overlapping meanings in natural language; or to provide other advice on term usage. It also refers the indexer/searcher to terms covering similar concepts, permitted in the Authority, but which have been restricted or expanded in their meaning and which may be more appropriate for the usage the indexer has in mind.

Mark Unknown
Mark unknown is used to index objects such as photographs where we cannot be certain as to the mark of aircraft due to its defining features being obscured.

Kevin Ward
Head of Collections Management
Royal Air Force Museum