Although metaphors are common in computing, particularly in human-computer interfaces, opinion is divided on their usefulness to users and little evidence is available to help the designer in choosing or implementing them. Effective use of metaphors depends on understanding their role in the computer interface, which in tum means building a model of the metaphor process. This thesis examines some of the approaches which might be taken in constructing such a model before choosing one and testing its applicability to interface design. Earlier research into interface metaphors used experimental psychology techniques which proved useful in showing the benefits or drawbacks of specific metaphors, but did not give a general model of the metaphor process. A cognitive approach based on mental models has proved more successful in offering an overall model of the process, although this thesis questions whether the researchers tested it adequately. Other approaches which have examined the metaphor process (though not in the context of human-computer interaction) have come from linguistic fields, most notably semiotics, which extends linguistics to non-verbal communication and thus could cover graphical user interfaces (GUls). The main work described in this thesis was the construction of a semiotic model of human-computer interaction. The basic principle of this is that even the simplest element of the user interface will signify many simultaneous meanings to the user. Before building the model, a set of assertions and questions was developed to check the validity of the principles on which the model was based. Each of these was then tested by a technique appropriate to the type of issue raised. Rhetorical analysis was used to establish that metaphor is commonplace in command-line languages, in addition to its more obvious use in GUIs. A simple semiotic analysis, or deconstruction, of the Macintosh user interface was then used to establish the validity of viewing user interfaces as semiotic systems. Finally, an experiment was carried out to test a mental model approach proposed by previous researchers. By extending their original experiment to more realistically complex interfaces and tasks and using a more typical user population, it was shown that users do not always develop mental models of the type proposed in the original research. The experiment also provided evidence to support the existence of multiple layers of signification. Based on the results of the preliminary studies, a simple means of testing the semiotic model's relevance to interface design was developed, using an interview technique. The proposed interview technique was then used to question two groups of users about a simple interface element. Two independent researchers then carried out a content analysis of the responses. The mean number of significations in each interview, as categorised by the researchers, was 15. The levels of signification were rapidly revealed, with the mean time for each interview being under two minutes, providing effective evidence that interfaces signify many meanings to users, a substantial number of which are easily retrievable. It is proposed that the interview technique could provide a practical and valuable tool for systems analysis and interface designers. Finally, areas for further research are proposed, in particular to ascertain how the model and the interview technique could be integrated with other design methods.

Submitted by Filipe dos Santos (fsantos@pucsp.br) on 2018-04-09T13:03:35Z No. of bitstreams: 1 João de Lira Cavalcante Neto.pdf: 48293206 bytes, checksum: 776e4367e7bf723f4083d0763dbac42b (MD5) / Made available in DSpace on 2018-04-09T13:03:35Z (GMT). No. of bitstreams: 1 João de Lira Cavalcante Neto.pdf: 48293206 bytes, checksum: 776e4367e7bf723f4083d0763dbac42b (MD5) Previous issue date: 2018-03-09 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The urban samba, which is a collective creation born in the midst spaces of black sociability into the communities of Rio de Janeiro at the turn of the 19th century to the 20th century, practiced in the poor backyards and obliviously apart from the modern concepts of originality and authorship, became suitable for the then-rising entertainment industry (characterized by the heyday of the Revue, the consolidation of the music industry, the emergence of radio and the advent of cinema). In this process of continuous traffic, samba and its rhythmic pulse — heirs of large African diaspora cultural ancestries, transmitted by oral tradition — were the object of successive incorporations and elaborations. Sanitized and metamorphosed into an object of the media consumption, elevated to the status of musical symbol by the nationalist project of the “Estado Novo”, samba answered this double, and harassment, developing strategies of a symbolic negotiation, absorbing new thematic of models of expression and textual and sonic possibilities. Backed up in the concept of circularity of Mikhail Bakhtin and, particularly, in Paul Zumthor's reflections on the effects of media coverage of oral culture, this research seeks to investigate, based on the collection of the “Radio Nacional”, today in the custody of the “Museu da Imagem e do Som do Rio de Janeiro” (MIS-RJ), the historical role that the programming of the station played in the phenomenon samba’s resignification, once cursed and peripheral musical gender turned into national hegemonic rhythm / O samba urbano, criação coletiva nascida em meio aos espaços de sociabilidade das comunidades negras cariocas na virada do século XIX para o século XX, praticado nos fundos dos quintais pobres e alheio aos modernos conceitos de originalidade e autoria, passou a ser apropriado pela então nascente indústria do entretenimento (caracterizada pelo auge do teatro de revista, a consolidação do mercado fonográfico, o surgimento do rádio e o advento do cinema). Nesse processo de trânsito contínuo, o samba e sua pulsação rítmica — herdeiros das ancestralidades culturais da grande diáspora africana, transmitida pela tradição oral —, foram alvo de incorporações e reelaborações sucessivas. Higienizado e metamorfoseado em objeto de consumo midiático, alçado à condição de símbolo musical pelo projeto nacionalista do Estado Novo, o samba respondeu a esse duplo assédio desenvolvendo estratégias de negociação simbólica, absorvendo novas temáticas, modos de expressão e possibilidades textuais e sonoras. Lastreada no conceito de circularidade cultural de Mikhail Bakhtin e, particularmente, nas reflexões de Paul Zumthor a respeito dos efeitos da mediatização da cultura oral, esta pesquisa busca investigar, com base no acervo da Rádio Nacional, hoje sob custódia do Museu da Imagem e do Som do Rio de Janeiro (MIS-RJ), o papel histórico que a programação da emissora desempenhou no fenômeno de ressignificação do samba, antes gênero musical maldito e periférico, convertido em ritmo nacional hegemônico