Tesis doctoral. Resumen en inglés
Title: Evaluating controlled vocabularies in indexing of documents by means of consistency indexes among indexers.
Director: Dr. Isidoro Gil Leiva
Department: Comunicación audiovisual, Documentación e Historia del Arte
PhD student: María Concepción Soler Monreal
Abstract:	
	
 	A study of interindexers consistency is carried out to evaluate the properties of a controlled language, a thesaurus, in comparison with the same thesaurus with scope notes in every term and with a list of free descriptors. The indexers selected had different levels of experience: on the one hand, students of Library and information science , and, on the other hand, professionals working at different documentation centres.
Chapter 1 justifies the choice of the topic, explains the purpose of the research and outlines the structure of the thesis. Chapter 2 is devoted to background information and the state-of-the-art. The concept of thesaurus, its evolution and the guidelines and norms for its elaboration are described. The different methods proposed to achieve interoperability among controlled vocabularies are also reviewed. In this chapter, thesauri are compared with other knowledge representation languages: ontologies, folksonomies and taxonomies. In the last part of chapter 2, the different methods of evaluation of thesauri are dealt with, both from an intrinsic perspective, either qualitative and quantitative, and from an extrinsic point of view.
Chapter 3, Material and Method, presents the three tools used in the research: a list of descriptors, a thesaurus and a thesaurus with scope notes in every term. They all belong to the library and information science domain. The characteristics of these three indexing language are described and the abbreviations and symbols used together with the semantic relations they contain are explained. The thesaurus is first analysed from a qualitative intrinsic point of view. Secondly, it is evaluated from a quantitative or statistic intrinsic point of view. The procedure to evaluate the tools is explained, the concept of consistency in indexing is summarised and its validity as a method for evaluating controlled vocabularies is accounted for.
Chapter 4 states and comments on the results of evaluating the three indexing languages used after applying the methodology presented in the previous chapter. Extrinsic evaluation is carried out by comparing the consistency indexes of the three tools (list of descriptors, thesaurus, increased thesaurus) in four groups of indexers: three groups of novel indexers and one group of expert indexers. Conclusions are drawn from the tables and data obtained and are presented in Chapter 5.
References are ordered alphabetically and appear in an independent section. 
Appendices comprise the indexed items (three summaries selected at random from Revista Española de Documentación Científica), and all the tests of indexing collected for the computation of the consistency indexes.
A CD-ROM is enclosed that includes the three indexing languages used in the tests: a list of descriptors of Library and information science, a thesaurus of library and information science, and the same thesaurus with scope notes in every term. Both thesauri consist of three presentations: systematic, alphabetical and permuted.