高齡者對電話語音階層數與目標語音出現順序之使用性研究

Usability of Hierarchical Telephone Voice Interfaces and Sequences of Targeted Voice Responses for the Elderly

探討高齡使用者對電話語音階層數與目標語音出現順序的使用性為本研究的目的。研究分兩個實驗進行，實驗一以電腦模擬不同電話語音的介面架構與目標語音出現的順序，探討電話語音介面之使用性。電話語音設有四種不同的階層數，三種不同的目標語音的出現順序。受測者有高齡者與年輕對照組各30名。實驗時，記錄操作時間、操作錯誤次數與主觀滿意度等三項。實驗二為探討電話語音介面的使用性與受測者工作記憶容量之間的關係。受測族群有高齡者與年輕族群各15名。實驗二的語音階層數設定有三種階層數；實驗二的執行步驟與實驗一相同。在實驗二執行之前，先評量受測者工作記憶的容量。從本研究的結果得知，影響電話語音介面的使用性主要有語音的階層數與目標語音出現的順序。當語音介面為四階層時，會增加對高齡者的工作記憶的要求，造成操作時間延長，與操作錯誤次數增加。整體而言，本研究的二階層、三階層的操作時間比四階層的操作時間較短，操作錯誤也較少。所以，電話語音介面建議採用二、三階層，可以降低操作過程所需的工作記憶，尤其對高齡者特別有益。

This study investigated the usability of hierarchical telephone voice interfaces and sequences of the targeted voice responses for the elderly using two experiments. Simulated with a notebook computer, the first experiment explored the usability of telephone voice interface for elderly people using four kinds of hierarchical telephone voice interfaces, and three sequences of the targeted voice responses in the targeted hierarchy. Thirty elderly people and thirty young people participated in the study. Each participant listened to the voice message on the telephone voice and inputted the number with the keypad depending on the experimental task. The operation time, accuracy and subjective evaluation of each task were recorded. The second experiment probed into the relationship between usability of telephone voice interface and working memory using two-, three- and four-step of hierarchical telephone voice interfaces. Working memory of fifteen elderly people and fifteen young people were measured. The experimental setup of the two experiments are the same. The results reveal that the hierarchical voice interfaces and the sequence of the targeted voice responses had significant effects on operation time, error rate and subjective evaluation. Elderly people took longer operation time and had higher error rates on the four-step hierarchical telephone voice interfaces that required more working memory. Two- and three-step hierarchical telephone voice interfaces took less operation time and had lower error rate than the four-step hierarchical telephone voice interfaces. Therefore, it is suggested that a two-step or three-step hierarchy with less working memory should be used for telephone voice interface, especially for the elderly.