由於普通話的語音系統與粤方言的相去甚遠，粤方言人士學習普通話語音時，來自粤方言的語音干擾對學習產生障礙，發音因而有所偏差。本研究應用多元概化理論的統計方法，分析由4位國家級普通話測試員對37名大學本科生朗讀1218個普通話帶調音節的評分數據，從而描繪香港學生朗讀普通話音節的能力面貌。 / 本研究在音節朗讀能力分析上應用概化理論，能同時估計影響分數變異的多個誤差來源，以及估計各側面的變異量及其佔總變異量的比例。通過本研究可以進一步了解來自題目、評分者的測量誤差對分數概化精確性的影響。而且，本研究採用的數據是對聲母、韻母、聲調的分項評分，把音節分解為三個變量來分析，能彌補整體性評分的不足，從而確定朗讀普通話音節時的偏誤所在。本研究對朗讀能力進行分解，首先是在音節的層面，對音節之下的子能力（聲母、韻母、聲調）進行解構分析。然後，則分別在聲母和韻母的層面探究兩者的子能力。研究發現，聲母、韻母、聲調之間的關聯程度很高，但韻母最能區分被試的朗讀能力，聲母卻最弱。各種韻母之間的協方差明顯比各種聲母之間的為大，表明各類韻母背後所隱含的共同能力相對較強。研究結果也顯示，被試能力和題目之間的交互作用是相對主要的誤差來源。 / 除了解構音節朗讀能力外，本研究還針對音節測試的實際情況進行應用研究。通過題目數量、評分者人數以及測量設計的改變，驗證不同測試條件下的概化係數等各種技術指標。結果顯示，各種改變條件的測試方案皆具相當高的測量信度，證明在實際的測試要求下，音節朗讀測試能測出被試的普通話語音能力。 / 本研究基於大量客觀數據而概括出的學習難點和規律，為普通話教與學提供客觀參照，更具針對性地教好、學好音節發音。同時，也有助本地測試機構，制定更符合粤方言者能力特質的音節題目。評分者效應的誤差則為評分者培訓提供訊息，有助提升評分的準確性，建設穩定的評分者團隊。 / As the phonological system of Putonghua is vastly different from that of Cantonese, the phonological interference from Cantonese poses critical learning obstacles to Cantonese speakers in their learning of Putonghua, which leads to various pronunciation errors. In this study, the statistical method Multivariate Generalizability Theory was used to analyze the rating data collected from 4 National Putonghua examiners' rating on the pronunciation of 1218 Putonghua syllables by 37 undergraduates at a university in Hong Kong. The purpose of this study was to examine the ability profiles and psychometric characteristics of Hong Kong students in the pronunciation of Putonghua syllables. / The application of generalizability theory on the study of the pronunciation competency of Putonghua syllables made it possible to analyze and estimate the multiple sources of errors which affected the variation of scores as well as the variance of each facet and its proportion against total variance. Through this study, it was possible to further understand the influence of measurement errors of test items and raters on the generalization of their accuracy. In the study, Putonghua syllables were divided into three variables (components: initials, finals and tones) and analytical scoring was applied in the analyses that could specify the location of errors in pronunciation, thus partly remedying the deficiency of holistic scoring. Deconstruction analysis of pronunciation competence was carried out in a 2-level hierarchy. First, the deconstruction took place at syllables in which initials, finals and tones were the sub-skills. Second, the initials and finals were also deconstructed. Research findings showed that correlations among initials, finals and tones were relatively high and that finals were the strongest in differentiating pronunciation competence while initials were the weakest. The covariances among various finals were apparently higher than those of initials. This implies that the mutual hidden competence linked to various types of finals was relatively strong. Findings also revealed that the interaction between subject’s competence and test items was the main source of errors. / In addition to the deconstruction analysis of pronunciation competence, applied research basing on the authentic situations of Putonghua tests was also conducted. Verification of technical specifications, including generalizability coefficients, was carried out under different testing conditions through changing test design and the number of test items and raters. The results showed that various testing solutions with the change in testing conditions possess high degree of measurement reliability, suggesting that syllable reading test could be used to examine pronunciation competence under authentic testing conditions. / In this study, learning difficulties and their patterns, which are derived from abundant unprejudiced data, provide objective reference to the teaching and learning of Putonghua syllable pronunciation with clear targets. These findings are also useful to local testing institutions in stipulating syllable reading tests which better suit the competence characteristics of Cantonese speakers. Furthermore, data and study results on rater errors offer reference for rater training which helps to promote the accuracy of rating, thus strengthening the quality of the rating team. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / 陳志良. / "2013年7月". / "2013 nian 7 yue". / Thesis (Ed.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 119-127). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in Chinese and English. / Chen Zhiliang. / Chapter 第一章 --- 緒論 --- p.1 / Chapter 1.1 --- 研究背景 --- p.1 / Chapter 1.2 --- 研究的目的、問題、預設與假設、內容、意義 --- p.2 / Chapter 1.2.1 --- 研究目的 --- p.2 / Chapter 1.2.2 --- 研究問題 --- p.3 / Chapter 1.2.2.1 --- 音節的理論探討 --- p.3 / Chapter 1.2.2.2 --- 應用研究探討 --- p.4 / Chapter 1.2.3 --- 研究預設與假設 --- p.5 / Chapter 1.2.4 --- 研究內容 --- p.6 / Chapter 1.2.5 --- 研究意義 --- p.7 / Chapter 第二章 --- 文獻綜述 --- p.9 / Chapter 2.1 --- 普通話在香港的地位 --- p.9 / Chapter 2.2 --- 普通話音節與漢語拼音 --- p.12 / Chapter 2.3 --- 普通話音節分析 --- p.15 / Chapter 2.4 --- 方言地區的普通話音節教學與學習 --- p.17 / Chapter 2.5 --- 普通話音節評分方法 --- p.22 / Chapter 2.6 --- 概化理論在普通話測試上的應用 --- p.27 / Chapter 第三章 --- 研究方法 --- p.33 / Chapter 3.1 --- 數據收集程序 --- p.33 / Chapter 3.1.1 --- 被試 --- p.33 / Chapter 3.1.2 --- 題目 --- p.33 / Chapter 3.1.3 --- 評分者 --- p.35 / Chapter 3.1.4 --- 評分方法 --- p.35 / Chapter 3.2 --- 能力分解研究 --- p.36 / Chapter 3.2.1 --- 子研究一：音節研究 --- p.36 / Chapter 3.2.2 --- 子研究二：聲母研究 --- p.38 / Chapter 3.2.3 --- 子研究三：韻母研究 --- p.39 / Chapter 3.3 --- 應用研究 --- p.39 / Chapter 3.3.1 --- 子研究一：組卷啟示 --- p.40 / Chapter 3.3.2 --- 子研究二：考試設計探索 --- p.40 / Chapter 3.3.2.1 --- G研究 --- p.40 / Chapter 3.3.2.2 --- D₁研究：改變題目數量 --- p.40 / Chapter 3.3.2.3 --- D₂研究：改變評分者人數 --- p.41 / Chapter 3.3.2.4 --- D₃研究：（P：R）× I嵌套設計（不同的評分者評不同的被試） --- p.41 / Chapter 3.3.2.5 --- D₄研究：（I：P）× R嵌套設計（不同的被試朗讀不同的音節） --- p.42 / Chapter 第四章 --- 能力分解研究 --- p.44 / Chapter 4.1 --- 子研究一：音節研究（三個因子模型） --- p.44 / Chapter 4.1.1 --- G研究 --- p.44 / Chapter 4.1.1.1 --- 測量目標p --- p.45 / Chapter 4.1.1.2 --- 測量側面i --- p.45 / Chapter 4.1.1.3 --- 測量側面r --- p.46 / Chapter 4.1.1.4 --- 各效應之間的比較 --- p.46 / Chapter 4.1.1.5 --- 交互效應 --- p.47 / Chapter 4.1.2 --- 默認D研究 --- p.48 / Chapter 4.1.2.1 --- 概化全域 --- p.48 / Chapter 4.1.2.2 --- 默認D研究中的方差與協方差分量的估計 --- p.48 / Chapter 4.1.2.3 --- 默認D研究中各效應在三個變量上的概化係數等指標 --- p.49 / Chapter 4.1.2.4 --- 全域合成分數的研究 --- p.51 / Chapter 4.1.2.5 --- 各變量對整體測試的貢獻比例 --- p.52 / Chapter 4.1.3 --- D₁研究：改變評分者人數 --- p.52 / Chapter 4.1.3.1 --- 模式設計 --- p.52 / Chapter 4.1.3.2 --- 研究發現 --- p.53 / Chapter 4.1.4 --- 小結 --- p.54 / Chapter 4.2 --- 子研究二：聲母研究（七個因子模型） --- p.56 / Chapter 4.2.1 --- G研究 --- p.56 / Chapter 4.2.1.1 --- 測量目標p --- p.56 / Chapter 4.2.1.2 --- 測量側面i --- p.59 / Chapter 4.2.1.3 --- 測量側面r --- p.60 / Chapter 4.2.1.4 --- 各效應之間的比較 --- p.60 / Chapter 4.2.1.5 --- 交互效應 --- p.61 / Chapter 4.2.2 --- 默認D研究 --- p.62 / Chapter 4.2.2.1 --- 概化全域 --- p.62 / Chapter 4.2.2.2 --- 默認D研究中的方差與協方差分量的估計 --- p.62 / Chapter 4.2.2.3 --- 默認D研究中各效應在三個變量上的概化係數等指標 --- p.62 / Chapter 4.2.3 --- D₂研究：改變評分者人數 --- p.65 / Chapter 4.2.3.1 --- 模式設計 --- p.65 / Chapter 4.2.3.2 --- 研究發現 --- p.65 / Chapter 4.2.4 --- 小結 --- p.67 / Chapter 4.3 --- 子研究三：韻母研究（四個因子模型） --- p.69 / Chapter 4.3.1 --- G研究 --- p.69 / Chapter 4.3.1.1 --- 測量目標p --- p.70 / Chapter 4.3.1.2 --- 測量側面i --- p.71 / Chapter 4.3.1.3 --- 測量側面r --- p.71 / Chapter 4.3.1.4 --- 各效應之間的比較 --- p.72 / Chapter 4.3.1.5 --- 交互效應 --- p.72 / Chapter 4.3.2 --- 默認D研究 --- p.73 / Chapter 4.3.2.1 --- 概化全域 --- p.73 / Chapter 4.3.2.2 --- 默認D研究中的方差與協方差分量的估計 --- p.73 / Chapter 4.3.2.3 --- 默認D研究中各效應在三個變量上的概化係數等指標 --- p.74 / Chapter 4.3.3 --- D₃研究：改變評分者人數 --- p.76 / Chapter 4.3.3.1 --- 模式設計 --- p.76 / Chapter 4.3.3.2 --- 研究發現 --- p.76 / Chapter 4.3.4 --- 小結 --- p.78 / Chapter 4.4 --- 綜合討論 --- p.80 / Chapter 第五章 --- 應用研究 --- p.82 / Chapter 5.1 --- 描述統計 --- p.82 / Chapter 5.1.1 --- 平均分和標準差 --- p.82 / Chapter 5.1.2 --- 被試表現分析 --- p.85 / Chapter 5.2 --- 子研究一：組卷啟示 --- p.87 / Chapter 5.2.1 --- 難度控制組卷 --- p.87 / Chapter 5.2.2 --- 組卷策略 --- p.88 / Chapter 5.2.3 --- 借助計算機程序 --- p.90 / Chapter 5.2.4 --- 組卷方式 --- p.90 / Chapter 5.2.4.1 --- 教學導向組卷 --- p.90 / Chapter 5.2.4.2 --- 測試導向組卷 --- p.91 / Chapter 5.2.4.3 --- 教學導向與測試導向結合 --- p.92 / Chapter 5.2.5 --- 小結 --- p.92 / Chapter 5.3 --- 子研究二：考試設計探索 --- p.94 / Chapter 5.3.1 --- G研究 --- p.94 / Chapter 5.3.2 --- 默認D研究 --- p.95 / Chapter 5.3.3 --- D₁研究：改變題目數量 --- p.96 / Chapter 5.3.3.1 --- 取樣模式 --- p.96 / Chapter 5.3.3.2 --- 研究發現 --- p.96 / Chapter 5.3.4 --- D₂研究：改變評分者人數 --- p.97 / Chapter 5.3.4.1 --- 取樣模式 --- p.98 / Chapter 5.3.4.2 --- 研究發現 --- p.98 / Chapter 5.3.5 --- D₃研究：（P：R）× I嵌套設計（不同的評分者評不同的被試） --- p.99 / Chapter 5.3.5.1 --- 研究設計 --- p.99 / Chapter 5.3.5.2 --- 研究發現 --- p.101 / Chapter 5.3.6 --- D₄研究：（I：P）× R嵌套設計（不同的被試朗讀不同的音節） --- p.101 / Chapter 5.3.6.1 --- 研究設計 --- p.101 / Chapter 5.3.6.2 --- 研究發現 --- p.102 / Chapter 5.3.7 --- 其他嵌套設計 --- p.103 / Chapter 5.3.8 --- 小結 --- p.105 / Chapter 第六章 --- 總結及建議 --- p.107 / Chapter 6.1 --- 結語 --- p.107 / Chapter 6.2 --- 主要結論 --- p.108 / Chapter 6.2.1 --- 音節研究 --- p.108 / Chapter 6.2.2 --- 聲母研究 --- p.109 / Chapter 6.2.3 --- 韻母研究 --- p.110 / Chapter 6.2.4 --- 評分者因素 --- p.111 / Chapter 6.2.5 --- 組卷啟示 --- p.111 / Chapter 6.2.6 --- 考試設計探索 --- p.112 / Chapter 6.3 --- 研究的不足 --- p.113 / Chapter 6.3.1 --- 被試的同質性 --- p.113 / Chapter 6.3.2 --- 題目側面的細化 --- p.114 / Chapter 6.3.3 --- 選題拼卷的聲韻覆蓋 --- p.114 / Chapter 6.4 --- 主要建議 --- p.115 / Chapter 6.4.1 --- 分項評分 --- p.115 / Chapter 6.4.2 --- 測試設計 --- p.116 / Chapter 6.4.3 --- 評分者人數與題目數量之間的關係 --- p.116 / Chapter 6.4.4 --- 音節教學和評分者培訓 --- p.117 / Chapter 6.4.5 --- 擴大研究對象 --- p.117 / Chapter 6.4.6 --- 擴大題目側面 --- p.118 / Chapter 6.4.7 --- 借助計算機程序 --- p.118 / 參考文獻 --- p.119 / Chapter 附錄 1 --- 音節與漢字對照表 --- p.128 / Chapter 附錄 2 --- 1218 個音節 --- p.136 / Chapter 附錄 3 --- 按聲母排列的音節難度表 --- p.144 / Chapter 附錄 4 --- 以聲母分類隨機選取的 100 音節試卷 --- p.156 / Chapter 附錄 5 --- 音節研究 mGENOVA程序 --- p.158

Made available in DSpace on 2016-03-15T19:47:27Z (GMT). No. of bitstreams: 1 Rosalina Brites de Assuncao.pdf: 1666468 bytes, checksum: d06f2a575fae1e9205521169ae939a22 (MD5) Previous issue date: 2011-12-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper intends to investigate how an obligatory tone is constructed in the texts that materialize the Landless Workers Movement (MST) and the Ministry of Education and Culture (MEC) discourse about an educational proposal to the rural population. Our corpus is based on five texts that belong to the Dossiê MST School collection and two of the National Council of Education/MEC Resolutions: Resolution CEB/CNE nº 1/2002 and Resolution CEB/CNE nº2/2008. At first, the aim is to analyze the discourse strategies that both enunciators used in their discourses, to produce a demanding tone in the enunciation, permitting to outline the image which they construct of themselves in the discourse. Secondly, it seeks to discover, through the analysis of the heterogeneity enunciative of each discourse, the ideological position of the enunciators and to reveal their intention within their education proposal. The analysis was made according to the theoretical assumptions of the French line of the Discourse Analysis as presented in Maingueneau (2004, 2008), Orlandi (2007), Brandão (2004), Amossy (2005). The issues that focus on enunciation projection in the statements are linked to the ideas of the Enunciation theory, based on the studies of Benveniste (1989), Authier-Revuz (2004), Fiorin (1999). The linguistic modalization analysis is subsidized by the Functionalist theory according to Halliday (1985), Hengeveld (2004), Palmer (1986) and Neves (2007). The results demonstrate that the idea of obligation shown in both discourses is constructed in a different way. The enunciative organization shows that, in the MST discourse, the tone of obligation is more impositive, which at discourse surface, behaves as an emancipation role. In the governments discourse, MEC, the tone is less mandatory and has the paper to include the countrymen in the culture and values of the burgeoise society. However, the hypothesis which is intended to be proved is that the option for the mandatory tone used by both enunciators is a discourse strategy which is constituted as by a power dispute between equality and difference, in which the MEC discourse intends to silence the MST movement and the MST aims to unstable the State s Education proposal. / A presente pesquisa pretende investigar como se constrói o tom de obrigatoriedade em textos que materializam o discurso do MST e o do MEC sobre uma proposta de educação para a população do meio rural. Tomam-se como corpus de pesquisa cinco textos pertencentes à coletânea Dossiê MST Escola e duas Resoluções do Conselho Nacional de Educação/MEC: Resolução CEB/CNE nº 1/2002 e Resolução CEB/CNE nº2/2008. Num primeiro momento, busca-se analisar as estratégias discursivas que os enunciadores de ambos os discursos mobilizam para imprimir no enunciado o tom de obrigatoriedade que permite delinear a imagem que constroem de si no discurso. Num segundo momento, objetiva-se verificar, mediante a análise da heterogeneidade enunciativa de cada discurso, o posicionamento ideológico dos enunciadores e desvelar a intencionalidade de suas propostas de educação. Como fundamentação teórica para as análises adotam-se os pressupostos teóricos da análise do discurso de linha francesa, conforme os estudos de Maingueneau (2004, 2008), Orlandi (2007), Brandão (2004), Amossy (2005). Intervêm noções ligadas à teoria da enunciação, pelas quais se focalizam as questões da projeção da enunciação no enunciado, conforme os estudos de Benveniste (1989), Authier-Revuz (2004), Fiorin (1999). Para a análise da modalização linguística consideram-se os fundamentos da teoria funcionalista da linguagem, segundo Halliday (1985), Hengeveld (2004), Palmer (1986) e Neves (2007). Os resultados da análise apontam que a noção de obrigatoriedade nos dois discursos é construída de maneira diferenciada. No discurso do MST, a forma de organização dos enunciados revela que o tom de obrigatoriedade é mais impositivo, desempenhando, na superfície do discurso, um papel emancipatório. No discurso do MEC, esse tom é menos autoritário e tem o papel de incluir o homem do campo na cultura e nos valores da sociedade burguesa. Entretanto a hipótese que se procura comprovar é a de que a opção pelo tom de obrigatoriedade por ambos os enunciadores é uma estratégia discursiva que se constitui por um jogo de poder entre igualdade e diferença, em que o discurso oficial busca silenciar o discurso do movimento e o discurso do MST visa a desestabilizar a proposta de educação do Estado.

For people without speech, voice output communication aids are an assistive technology––but can also be restrictive: whilst Text-To-Speech synthesis can say anything, it affords little choice of how this is spoken. An absence of nuanced tone of voice can inhibit social interaction. This research explores this profound but relatively overlooked issue in augmentative and alternative communication through the lens––with the sensibilities and skills––of interaction design. Tone of voice is such an elusive and intangible quality: difficult for even phoneticians to define, let alone AAC users and carers to discuss in the context of their everyday lives. Therefore the activities of design exploration and design practice have been employed to visualise tone of voice, in order to catalyse new conversations, through two original research projects: Six Speaking Chairs, curated with Andrew Cook, is a collection of interactive artefacts that illustrate alternative models of tone of voice developed by academics and practitioners as diverse as sociolinguists and playwrights;Speech Hedge, created with the assistance of Ryan McLeod, is a visualisation of how someone might interact with nuanced tone of voice using a conventional communication aid in combination with an interface on a smart phone. Audience responses to each project have illuminated the perspectives from which laypeople conceive of tone of voice, challenging the conventional emotional model that dominates speech technology in favour of something more complex and heterogeneous. In order to reconcile such complexity with simplicity of use, design principles have been distilled that could inspire future user interfaces but also inform further research. This research has been published and presented within different academic fields, including design research, interaction design and augmentative and alternative communication.

Objective The purposes of the study were: (1) To evaluate the intrasession test-retest reliability of pure-tone thresholds measured in the 0.5–16 kHz frequency range for a group of otologically healthy subjects using Sennheiser HDA 200 circumaural and Etymotic Research ER-2 insert earphones and (2) to compare the data with existing criteria of significant threshold shifts related to ototoxicity and noise-induced hearing loss. Design Auditory thresholds in the frequency range from 0.5 to 6 kHz and in the extended high-frequency range from 8 to 16 kHz were measured in one ear of 138 otologically healthy subjects (77 women, 61 men; mean age, 24.4 yr; range, 12–51 yr) using HDA 200 and ER-2 earphones. For each subject, measurements of thresholds were obtained twice for both transducers during the same test session. For analysis, the extended high-frequency range from 8 to 16 kHz was subdivided into 8 to 12.5 and 14 to 16 kHz ranges. Data for each frequency and frequency range were analyzed separately. Results There were no significant differences in repeatability for the two transducer types for all frequency ranges. The intrasession variability increased slightly, but significantly, as frequency increased with the greatest amount of variability in the 14 to 16 kHz range. Analyzing each individual frequency, variability was increased particularly at 16 kHz. At each individual frequency and for both transducer types, intrasession test-retest repeatability from 0.5 to 6 kHz and 8 to 16 kHz was within 10 dB for >99% and >94% of measurements, respectively. The results indicated a false-positive rate of Conclusion Repeatability was similar for both transducer types. Intrasession test-retest repeatability from 0.5 to 12.5 kHz at each individual frequency including the frequency range susceptible to noise-induced hearing loss was excellent for both transducers. Repeatability was slightly, but significantly poorer in the frequency range from 14 to 16 kHz compared with the frequency ranges from 0.5 to 6 or 8 to 12.5 kHz. Measurements in the extended high-frequency range from 8 to 14 kHz, but not up to 16 kHz, may be recommended for monitoring purposes.

No description available.

Otoacoustic emission (OAE) data recorded for tone bursts presented separately and as a two-tone burst complex, that had been reported previously [Yoshikawa, H., Smurzynski, J., Probst R., 2000. Suppression of tone burst evoked otoacoustic emissions in relation to frequency separation. Hear. Res. 148, 95–106], were re-processed using the method of adaptive approximations by matching pursuit (MP). Two types of stimuli were applied to record tone burst OAEs (TBOAEs): (a) cosine-windowed tone bursts of 5-ms duration with center frequencies of 1, 1.5, 2 and 3kHz, (b) complex stimuli consisting of a digital addition of the 1-kHz tone burst together with either the 1.5-, 2- or 3-kHz tone burst. The MP method allowed decomposition of signals into waveforms of defined frequency, latency, time span, and amplitude. This approach provided a high time–frequency (t–f) resolution and identified patterns of resonance modes that were characteristic for TBOAEs recorded in each individual ear. Individual responses to single-tone bursts were processed off-line to form ‘sum of singles’ responses. The results confirmed linear superposition behavior for a frequency separation of two-tone bursts of 2kHz (the 1-kHz and 3-kHz condition). For the 1, 1.5-kHz condition, the MP results revealed the existence of closely positioned resonance modes associated with responses recorded individually with the stimuli differing in frequency by 500Hz. Then, the differences between t–f distributions calculated for dual (two-tone bursts) and sum-of-singles conditions exhibited mutual suppression of resonance modes common to both stimuli. The degree of attenuation depended on the individual pattern of characteristic resonance modes, i.e., suppression occurred when two resonant modes excited by both stimuli overlapped. It was postulated that the suppression observed in case of dual stimuli with closely-spaced components is due to mutual attenuation of the overlapping resonance modes.

No description available.

Abstract not available

<p>Touch-tone interfaces are today widely used in help-centers and support services. Studies have shown that interfaces like these have many limitations and are therefore hard to design. MVAS is a voicemail interface using touch- tone input for navigation. Today, shortcomings in the interface limit the users’ ability to use the functionality in a satisfying way. This thesis describes a mainly qualitative study which evaluates and tests the interface of MVAS to come up with how the interface should be designed to be easier to use. The results show that the usability of MVAS is poor but the functionality of the same is both impressive and appreciated. The suggested redesign of the system, based on the identified usability problems, considers both the interaction model used in the interface as well as the conformity to the set of heuristics used in the evaluation. The proposed redesign keeps all the functionality in the system intact and also makes the functionality more explicit through improving the usability. A more explicit structure will facilitate usage of a larger portion of the functionality. However, the limitation of the key-pad affects the redesign so the most favorable design is unreachable. If the interaction model is changed or furthered developed to allow speech input the limitations experienced with the current redesign will diminish and a higher degree of usability can be reached.</p>

<p>Postoperative nausea and vomiting (PONV) is still a clinical problem and its incidence is unacceptably high. After the introduction of propofol as an agent for induction and maintenance of anesthesia, it was reported that the incidence of PONV was lower. It was also proposed that propofol possesses antiemetic effects. Dopamine, serotonin and opioids may contribute to PONV. Therefore the purpose of these investigations was to evaluate if propofol has dopamine, serotonin or opioid antagonistic effects and if a subhypnotic infusion of propofol decreases the incidence of PONV. </p><p>Nausea and vomiting were induced in volunteers by a dopamine agonist, apomorphine, and by ipecacuanha which releases serotonin from the enterochromaffin cells in the gut. The effects of propofol on gastric emptying and orocecal transit time were evaluated in volunteers with the paracetamol method and by measuring the endtidal hydrogen concentration after ingestion of the trisaccharide raffinose. The effects of morphine on gastric emptying and gastric tone were studied in patients before surgery with the paracetamol method and with an electronic barostat, respectively. The effects of low dose propofol for prophylaxis of PONV were studied in 172 patients undergoing breast and abdominal surgery. Propofol prophylaxis was compared with a multidrug regimen consisting of dexamethasone and three antiemetic drugs, ondansetron, droperidol and metoclopramide. </p><p>Propofol did not abolish apomorphine-induced vomiting but reduced the number of retchings induced by ipecacuanha. Propofol sedation did not influence gastric emptying of liquids but it slightly prolonged orocecal transit time. Gastric relaxation induced by morphine was abolished by propofol but propofol did not abolish morphine-induced delay of gastric emptying. Propofol in a low dose infusion reduced the incidence of PONV but nausea and especially vomiting increased significantly after termination of the infusion. Pro- phylaxis with the multidrug regimen was very effective in preventing PONV. </p><p>These studies have shown that propofol does not have any dopamine antagonistic effect but may have a weak serotonin antagonistic effect. Propofol cannot abolish morphine-induced delay of gastric emptying. Low dose propofol infusion was effective in preventing PONV as long as the infusion was ongoing but after termination of the infusion nausea and especially vomiting substantially increased. The multidrug regimen (dexamethasone, ondansetron, droperidol, metoclopramide) was very effective in preventing PONV and can be recommended as prophylaxis in patient groups with a known high risk for PONV. </p>