There has been limited research done to determine the impact of the use of colour on communication displays in the facilitation of graphic symbol location within an overlay. As many Augmentative and Alternative Communication systems are pictorial in nature, it is of importance that interventionists are aware of the potential impact that colour can have on the accuracy and rate of symbol location. The present study is based on a study by Wilkinson, Carlin and Jagaroo (2006) and used the same testing material (colour conditions) whilst modifying the type of exposure to these colour conditions. This study investigated the effect of sequential exposure of colour conditions on the rate and accuracy of graphic symbol location. The study used a comparative, non-experimental group design using sixty participants who conformed to specific selection criteria. Each participant was exposed to three colour conditions that were placed in a specific sequential order. The participants were required to match a target, graphic symbol within an array of symbols in the differing colour conditions. Two different types of graphic symbols were used meaningful (Type A) and arbitrary (Type B). Two different colour sets were also used with the colour conditions varying in each set. Set 1 were the sequentially ordered colour conditions of same colour, mixed colour and unique colour symbols (difficult to easy) while Set 2 were the sequentially ordered colour conditions of unique colour, mixed colour and same colour symbols (easy to difficult). The major findings of the study were as follows. In terms of rate, there was a significant interaction noted between the two symbol types and their sequential ordering. The time taken (rate) for the location of the nonreferential forms was slower than that taken for the meaningful symbols. The reasoning behind this result could be that the non-referential forms were not as familiar to the participants as the meaningful symbols were. Thus, the rate recording of the meaningful symbols and the non-referential forms described in the three colour conditions was different and could be noted in the results. In terms of accuracy, a significant impact was noted between the two symbol types when the first manner of sequential ordering was used, however, there were no significant differences noted when the second manner of sequential ordering was used. This implies greater accuracy was recorded when the second manner of sequential ordering was used as this ordering appeared to be “visually easier” for the location of symbols. / Dissertation (MA)--University of Pretoria, 2009. / Centre for Augmentative and Alternative Communication / unrestricted

本文主要探討台灣電視新聞的言談結構(discourse structure)，以及標示各單位的言談標記(discourse marker)。本研究分析25則電視新聞，文類限定於社會新聞。首先，在結構上，每一則新聞包含兩大結構︰導語(news kernel)以及旁白與影片(news body)。兩大結構又可細分為七個較小的單位，分別為︰開場白 (opening)、摘要 (abstract of the news)、事件現場畫面 (event scene presentation)、主要新聞事件 (main news events)、後續發展 (follow-up)、評語 (evaluation)、結尾 (routine ending)。而這七個單位還可再細分為更小的單位。此外，本文所探討的言談標記可分為五類︰1. 指涉詞 (referential forms) 2. 連詞 (connectives) 3. 地方副詞 (locative phrase) 4. 話題轉換填充詞 (topic shift fillers) 5. 畫面轉換 (shot shift)。是故，本文研究重點有二︰1.將新聞結構分為三個階層—Level 1、Level 2、Level 3，並探討出現於不同階層的言談標記在類型與數量上是否反映出階層 (hierarchy)？ 2. 標示各個結構的言談標記為何？ 研究結果指出︰1. 三個階層的言談標記在類型上除了Level 1固定有畫面轉換之外，其餘兩個階層皆無固定的言談標記。另外，在數量上僅Level 1可同時出現多個言談標記，Level 2與Level 3在數量上並無差異，顯示出電視新聞為口說語(spoken language)的一種，訊息與訊息之間的連結性比表現出文體結構階層性更為重要 2. 標示各單位的言談標記並無一致性。受到各單位特性影響，言談標記呈現不同的分佈。 / The present study examines twenty five pieces of broadcast news about crimes and damages in Taiwan. The purpose is to examine the relationship between the discourse structures and their corresponding markers. The discourse structure of a piece of broadcast news is divided into seven components and they are categorized into three levels. Level 1 includes news kernel and news body. Level 2 includes abstract in news kernel, main news events, follow-ups, evaluation, and routine ending in news body. Level 3 contains the smaller units in the Level 2 units. The boundary markers to be examined are divided into four categories: topic shift filler, referential forms, connectives, and shot shift. The present study has two major findings. First, the amounts of markers only show significant difference in Level 1. Down to Level 2 and Level 3, linearity overrides hierarchy. Second, the types of markers are decided by the nature of each unit. The opening is always marked by shot shift and speaker shift plus topic shift fillers/temporals/additives. The abstract section is marked by locative phrase plus referential forms. The event scene presentation section is marked by shot shift and speaker shift plus referential forms. The main news events section is marked by shot shift plus temporals which signal the exact time. Then, the follow-up section is marked by shot shift plus referential forms/connectives. The evaluation section is marked by shot shift plus referential forms. The routine ending section is marked by a relatively longer pause.