Search (16 results, page 1 of 1)

  • × author_ss:"Tudhope, D."
  1. Tudhope, D.; Taylor, C.; Beynon-Davies, P.: Classification and hypermedia (1995) 0.03
    0.028916951 = product of:
      0.057833903 = sum of:
        0.057833903 = product of:
          0.115667805 = sum of:
            0.115667805 = weight(_text_:classification in 4575) [ClassicSimilarity], result of:
              0.115667805 = score(doc=4575,freq=4.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.69665456 = fieldWeight in 4575, product of:
                  2.0 = tf(freq=4.0), with freq of:
                    4.0 = termFreq=4.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.109375 = fieldNorm(doc=4575)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Source
    Proceedings of the 6th ASIS SIG/CR Classification Research Workshop, Oct. 8, 1995, Chicago, IL. Ed.: R.P. Schwartz et al
  2. Tudhope, D.: Knowledge Organization System Services : brief review of NKOS activities and possibility of KOS registries (2007) 0.02
    0.02119053 = product of:
      0.04238106 = sum of:
        0.04238106 = product of:
          0.08476212 = sum of:
            0.08476212 = weight(_text_:22 in 100) [ClassicSimilarity], result of:
              0.08476212 = score(doc=100,freq=2.0), product of:
                0.18256627 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.05213454 = queryNorm
                0.46428138 = fieldWeight in 100, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.09375 = fieldNorm(doc=100)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Date
    22. 9.2007 15:41:14
  3. Golub, K.; Hansson, J.; Soergel, D.; Tudhope, D.: Managing classification in libraries : a methodological outline for evaluating automatic subject indexing and classification in Swedish library catalogues (2015) 0.02
    0.017887725 = product of:
      0.03577545 = sum of:
        0.03577545 = product of:
          0.0715509 = sum of:
            0.0715509 = weight(_text_:classification in 2300) [ClassicSimilarity], result of:
              0.0715509 = score(doc=2300,freq=12.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.43094325 = fieldWeight in 2300, product of:
                  3.4641016 = tf(freq=12.0), with freq of:
                    12.0 = termFreq=12.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=2300)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Subject terms play a crucial role in resource discovery but require substantial effort to produce. Automatic subject classification and indexing address problems of scale and sustainability and can be used to enrich existing bibliographic records, establish more connections across and between resources and enhance consistency of bibliographic data. The paper aims to put forward a complex methodological framework to evaluate automatic classification tools of Swedish textual documents based on the Dewey Decimal Classification (DDC) recently introduced to Swedish libraries. Three major complementary approaches are suggested: a quality-built gold standard, retrieval effects, domain analysis. The gold standard is built based on input from at least two catalogue librarians, end-users expert in the subject, end users inexperienced in the subject and automated tools. Retrieval effects are studied through a combination of assigned and free tasks, including factual and comprehensive types. The study also takes into consideration the different role and character of subject terms in various knowledge domains, such as scientific disciplines. As a theoretical framework, domain analysis is used and applied in relation to the implementation of DDC in Swedish libraries and chosen domains of knowledge within the DDC itself.
    Source
    Classification and authority control: expanding resource discovery: proceedings of the International UDC Seminar 2015, 29-30 October 2015, Lisbon, Portugal. Eds.: Slavic, A. u. M.I. Cordeiro
  4. Binding, C.; Gnoli, C.; Tudhope, D.: Migrating a complex classification scheme to the semantic web : expressing the Integrative Levels Classification using SKOS RDF (2021) 0.02
    0.017887725 = product of:
      0.03577545 = sum of:
        0.03577545 = product of:
          0.0715509 = sum of:
            0.0715509 = weight(_text_:classification in 600) [ClassicSimilarity], result of:
              0.0715509 = score(doc=600,freq=12.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.43094325 = fieldWeight in 600, product of:
                  3.4641016 = tf(freq=12.0), with freq of:
                    12.0 = termFreq=12.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=600)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose The Integrative Levels Classification (ILC) is a comprehensive "freely faceted" knowledge organization system not previously expressed as SKOS (Simple Knowledge Organization System). This paper reports and reflects on work converting the ILC to SKOS representation. Design/methodology/approach The design of the ILC representation and the various steps in the conversion to SKOS are described and located within the context of previous work considering the representation of complex classification schemes in SKOS. Various issues and trade-offs emerging from the conversion are discussed. The conversion implementation employed the STELETO transformation tool. Findings The ILC conversion captures some of the ILC facet structure by a limited extension beyond the SKOS standard. SPARQL examples illustrate how this extension could be used to create faceted, compound descriptors when indexing or cataloguing. Basic query patterns are provided that might underpin search systems. Possible routes for reducing complexity are discussed. Originality/value Complex classification schemes, such as the ILC, have features which are not straight forward to represent in SKOS and which extend beyond the functionality of the SKOS standard. The ILC's facet indicators are modelled as rdf:Property sub-hierarchies that accompany the SKOS RDF statements. The ILC's top-level fundamental facet relationships are modelled by extensions of the associative relationship - specialised sub-properties of skos:related. An approach for representing faceted compound descriptions in ILC and other faceted classification schemes is proposed.
  5. Tudhope, D.; Hodge, G.: Terminology registries (2007) 0.02
    0.017658776 = product of:
      0.03531755 = sum of:
        0.03531755 = product of:
          0.0706351 = sum of:
            0.0706351 = weight(_text_:22 in 539) [ClassicSimilarity], result of:
              0.0706351 = score(doc=539,freq=2.0), product of:
                0.18256627 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.05213454 = queryNorm
                0.38690117 = fieldWeight in 539, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.078125 = fieldNorm(doc=539)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Date
    26.12.2011 13:22:07
  6. Binding, C.; Tudhope, D.: Terminology Web services (2010) 0.02
    0.015178238 = product of:
      0.030356476 = sum of:
        0.030356476 = product of:
          0.060712952 = sum of:
            0.060712952 = weight(_text_:classification in 4067) [ClassicSimilarity], result of:
              0.060712952 = score(doc=4067,freq=6.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.3656675 = fieldWeight in 4067, product of:
                  2.4494898 = tf(freq=6.0), with freq of:
                    6.0 = termFreq=6.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.046875 = fieldNorm(doc=4067)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Controlled terminologies such as classification schemes, name authorities, and thesauri have long been the domain of the library and information science community. Although historically there have been initiatives towards library style classification of web resources, there remain significant problems with searching and quality judgement of online content. Terminology services can play a key role in opening up access to these valuable resources. By exposing controlled terminologies via a web service, organisations maintain data integrity and version control, whilst motivating external users to design innovative ways to present and utilise their data. We introduce terminology web services and review work in the area. We describe the approaches taken in establishing application programming interfaces (API) and discuss the comparative benefits of a dedicated terminology web service versus general purpose programming languages. We discuss experiences at Glamorgan in creating terminology web services and associated client interface components, in particular for the archaeology domain in the STAR (Semantic Technologies for Archaeological Resources) Project.
    Content
    Teil von: Papers from Classification at a Crossroads: Multiple Directions to Usability: International UDC Seminar 2009-Part 2
  7. Tudhope, D.: Virtual architecture based on a binary relational model : a museum hypermedia application (1994) 0.01
    0.014458476 = product of:
      0.028916951 = sum of:
        0.028916951 = product of:
          0.057833903 = sum of:
            0.057833903 = weight(_text_:classification in 2801) [ClassicSimilarity], result of:
              0.057833903 = score(doc=2801,freq=4.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.34832728 = fieldWeight in 2801, product of:
                  2.0 = tf(freq=4.0), with freq of:
                    4.0 = termFreq=4.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=2801)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Reviews claims made for virtual architectures and proposes a semantic data model for hypermedia architecture. Semantic modelling and an extended binary relational model in particular, are outlined in the context of hypermedia. The binary relational store is a simple, uniform data structure, capable of representing abstraction in the application model. Pilot implementations of museum hypermedia systems demonstrate that the architecture is capable of supporting a variety of navigation techniques and authoring tools. Outlines the SHIC (Social History and Industrial Classification) museum classification schema, and discusses its implementation in a hypermedia system based on a binary relational store. Considers experiences with the prototypes and discusses feedback from the museum profession and general public. An extended binary relational model is particularly suited to certain forms of reasoning based on generalization
  8. Tudhope, D.; Binding, C.: Faceted thesauri (2008) 0.01
    0.011684213 = product of:
      0.023368426 = sum of:
        0.023368426 = product of:
          0.04673685 = sum of:
            0.04673685 = weight(_text_:classification in 1855) [ClassicSimilarity], result of:
              0.04673685 = score(doc=1855,freq=2.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.28149095 = fieldWeight in 1855, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0625 = fieldNorm(doc=1855)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    The basic elements of faceted thesauri are described, together with a review of their origins and some prominent examples. Their use in browsing and searching applications is discussed. Faceted thesauri are distinguished from faceted classification schemes, while acknowledging the close similarities. The paper concludes by comparing faceted thesauri and related knowledge organization systems to ontologies and discussing appropriate areas of use.
  9. Golub, K.; Tudhope, D.; Zeng, M.L.; Zumer, M.: Terminology registries for knowledge organization systems : functionality, use, and attributes (2014) 0.01
    0.010595265 = product of:
      0.02119053 = sum of:
        0.02119053 = product of:
          0.04238106 = sum of:
            0.04238106 = weight(_text_:22 in 1347) [ClassicSimilarity], result of:
              0.04238106 = score(doc=1347,freq=2.0), product of:
                0.18256627 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.05213454 = queryNorm
                0.23214069 = fieldWeight in 1347, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.046875 = fieldNorm(doc=1347)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Date
    22. 8.2014 17:12:54
  10. Golub, K.; Lykke, M.; Tudhope, D.: Enhancing social tagging with automated keywords from the Dewey Decimal Classification (2014) 0.01
    0.010327483 = product of:
      0.020654965 = sum of:
        0.020654965 = product of:
          0.04130993 = sum of:
            0.04130993 = weight(_text_:classification in 2918) [ClassicSimilarity], result of:
              0.04130993 = score(doc=2918,freq=4.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.24880521 = fieldWeight in 2918, product of:
                  2.0 = tf(freq=4.0), with freq of:
                    4.0 = termFreq=4.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=2918)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose - The purpose of this paper is to explore the potential of applying the Dewey Decimal Classification (DDC) as an established knowledge organization system (KOS) for enhancing social tagging, with the ultimate purpose of improving subject indexing and information retrieval. Design/methodology/approach - Over 11.000 Intute metadata records in politics were used. Totally, 28 politics students were each given four tasks, in which a total of 60 resources were tagged in two different configurations, one with uncontrolled social tags only and another with uncontrolled social tags as well as suggestions from a controlled vocabulary. The controlled vocabulary was DDC comprising also mappings from the Library of Congress Subject Headings. Findings - The results demonstrate the importance of controlled vocabulary suggestions for indexing and retrieval: to help produce ideas of which tags to use, to make it easier to find focus for the tagging, to ensure consistency and to increase the number of access points in retrieval. The value and usefulness of the suggestions proved to be dependent on the quality of the suggestions, both as to conceptual relevance to the user and as to appropriateness of the terminology. Originality/value - No research has investigated the enhancement of social tagging with suggestions from the DDC, an established KOS, in a user trial, comparing social tagging only and social tagging enhanced with the suggestions. This paper is a final reflection on all aspects of the study.
  11. Souza, R.R.; Tudhope, D.; Almeida, M.B.: Towards a taxonomy of KOS (2012) 0.01
    0.010223686 = product of:
      0.020447372 = sum of:
        0.020447372 = product of:
          0.040894743 = sum of:
            0.040894743 = weight(_text_:classification in 139) [ClassicSimilarity], result of:
              0.040894743 = score(doc=139,freq=2.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.24630459 = fieldWeight in 139, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=139)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    This paper analyzes previous work on the classification of Knowledge Organization Systems (KOS), discusses strengths and weaknesses, and proposes a new and integrative framework. It argues that current analyses of the KOS tend to be idiosyncratic and incomplete, relying on a limited number of dimensions of analysis. The paper discusses why and how KOS should be classified on a new basis. Based on the available literature and previous work, the authors propose a wider set of dimensions for the analysis of KOS. These are represented in a taxonomy of KOS. Issues arising are discussed.
  12. Khoo, M.J.; Ahn, J.-w.; Binding, C.; Jones, H.J.; Lin, X.; Massam, D.; Tudhope, D.: Augmenting Dublin Core digital library metadata with Dewey Decimal Classification (2015) 0.01
    0.010118825 = product of:
      0.02023765 = sum of:
        0.02023765 = product of:
          0.0404753 = sum of:
            0.0404753 = weight(_text_:classification in 2320) [ClassicSimilarity], result of:
              0.0404753 = score(doc=2320,freq=6.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.24377833 = fieldWeight in 2320, product of:
                  2.4494898 = tf(freq=6.0), with freq of:
                    6.0 = termFreq=6.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.03125 = fieldNorm(doc=2320)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose - The purpose of this paper is to describe a new approach to a well-known problem for digital libraries, how to search across multiple unrelated libraries with a single query. Design/methodology/approach - The approach involves creating new Dewey Decimal Classification terms and numbers from existing Dublin Core records. In total, 263,550 records were harvested from three digital libraries. Weighted key terms were extracted from the title, description and subject fields of each record. Ranked DDC classes were automatically generated from these key terms by considering DDC hierarchies via a series of filtering and aggregation stages. A mean reciprocal ranking evaluation compared a sample of 49 generated classes against DDC classes created by a trained librarian for the same records. Findings - The best results combined weighted key terms from the title, description and subject fields. Performance declines with increased specificity of DDC level. The results compare favorably with similar studies. Research limitations/implications - The metadata harvest required manual intervention and the evaluation was resource intensive. Future research will look at evaluation methodologies that take account of issues of consistency and ecological validity. Practical implications - The method does not require training data and is easily scalable. The pipeline can be customized for individual use cases, for example, recall or precision enhancing. Social implications - The approach can provide centralized access to information from multiple domains currently provided by individual digital libraries. Originality/value - The approach addresses metadata normalization in the context of web resources. The automatic classification approach accounts for matches within hierarchies, aggregating lower level matches to broader parents and thus approximates the practices of a human cataloger.
  13. Tudhope, D.; Taylor, C.: Navigation via similarity (1997) 0.01
    0.00876316 = product of:
      0.01752632 = sum of:
        0.01752632 = product of:
          0.03505264 = sum of:
            0.03505264 = weight(_text_:classification in 155) [ClassicSimilarity], result of:
              0.03505264 = score(doc=155,freq=2.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.21111822 = fieldWeight in 155, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.046875 = fieldNorm(doc=155)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Describes a research project, in which similarity measures have been extended to include imprecise matching over different dimensions of structured classification schemes (subject, soace, time). The semantic similarity of information units forms the basis for the automatic construction of links and is integrated into hypermedia navigation. Outlines a semantic hypermedia architecture, and a prototype museum social history application. Presents illustrative navigation scenarios which make use of a navigation via similarity tool. The temporal mesaures of semantic closeness underpin the similarity tool. The temporal measures takes account of periods as well as time points. The most general measure is based on a traversal of a semantic net, taking into account relationship type and level of specialisation. It is based on a notion of closeness rather than absolute distance, and returns a seit of semantically close terms. Discusses a methods of calculating semantic similarity between sets of index terms, based on the maximal closeness values achieved by each term
  14. Tudhope, D.; Binding, C.; Blocks, D.; Cuncliffe, D.: Representation and retrieval in faceted systems (2003) 0.01
    0.0073026326 = product of:
      0.014605265 = sum of:
        0.014605265 = product of:
          0.02921053 = sum of:
            0.02921053 = weight(_text_:classification in 2703) [ClassicSimilarity], result of:
              0.02921053 = score(doc=2703,freq=2.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.17593184 = fieldWeight in 2703, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=2703)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    This paper discusses two inter-related themes: the retrieval potential of faceted thesauri and XML representations of fundamental facets. Initial findings are discussed from the ongoing 'FACET' project, in collaboration with the National Museum of Science and Industry. The work discussed seeks to take advantage of the structure afforded by faceted systems for multi-term queries and flexible matching, focusing in this paper an the Art and Architecture Thesaurus. A multi-term matching function yields ranked results with partial matches via semantic term expansion, based an a measure of distance over the semantic index space formed by thesaurus relationships. Our intention is to drive the system from general representations and a common query structure and interface. To this end, we are developing an XML representation based an work by the Classification Research Group an fundamental facets or categories. The XML representation maps categories to particular thesauri and hierarchies. The system interface, which is configured by the mapping, incorporates a thesaurus browser with navigation history together with a term search facility and drag and drop query builder.
  15. Matthews, B.; Jones, C.; Puzon, B.; Moon, J.; Tudhope, D.; Golub, K.; Nielsen, M.L.: ¬An evaluation of enhancing social tagging with a knowledge organization system (2010) 0.01
    0.0073026326 = product of:
      0.014605265 = sum of:
        0.014605265 = product of:
          0.02921053 = sum of:
            0.02921053 = weight(_text_:classification in 4171) [ClassicSimilarity], result of:
              0.02921053 = score(doc=4171,freq=2.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.17593184 = fieldWeight in 4171, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=4171)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose - Traditional subject indexing and classification are considered infeasible in many digital collections. This paper seeks to investigate ways of enhancing social tagging via knowledge organization systems, with a view to improving the quality of tags for increased information discovery and retrieval performance. Design/methodology/approach - Enhanced tagging interfaces were developed for exemplar online repositories, and trials were undertaken with author and reader groups to evaluate the effectiveness of tagging augmented with control vocabulary for subject indexing of papers in online repositories. Findings - The results showed that using a knowledge organisation system to augment tagging does appear to increase the effectiveness of non-specialist users (that is, without information science training) in subject indexing. Research limitations/implications - While limited by the size and scope of the trials undertaken, these results do point to the usefulness of a mixed approach in supporting the subject indexing of online resources. Originality/value - The value of this work is as a guide to future developments in the practical support for resource indexing in online repositories.
  16. Golub, K.; Soergel, D.; Buchanan, G.; Tudhope, D.; Lykke, M.; Hiom, D.: ¬A framework for evaluating automatic indexing or classification in the context of retrieval (2016) 0.01
    0.0073026326 = product of:
      0.014605265 = sum of:
        0.014605265 = product of:
          0.02921053 = sum of:
            0.02921053 = weight(_text_:classification in 3311) [ClassicSimilarity], result of:
              0.02921053 = score(doc=3311,freq=2.0), product of:
                0.16603322 = queryWeight, product of:
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.05213454 = queryNorm
                0.17593184 = fieldWeight in 3311, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.1847067 = idf(docFreq=4974, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=3311)
          0.5 = coord(1/2)
      0.5 = coord(1/2)