# 易用度

(由易用跳轉過嚟)

## 定義

 「 原版英文："... the extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use." 粵文翻譯：（易用度係）一件產品有幾能夠俾特定嘅用家用嚟達到特定（件產品設計嚟達到嘅）目的，而且喺特定嘅情境下達到目的上嚟有效果、有效率同埋能夠令用家滿意。 」

${\displaystyle y=C_{1}x^{b}}$

## 評估

• 易用度測試（usability testing）：指真係搵用家（受試者）返嚟試吓用個系統；喺呢個測試過程當中，設計者會要求啲受試者自由噉用吓，跟住又會叫佢哋試吓用某啲特定嘅功能嚟達到某啲里程碑；喺呢個測試過程當中，設計者會用觀察受試者嘅行為，又會某啲方法量度一啲反映易用度嘅指標，「指標」包括「受試者用咗幾多時間嚟達到里程碑」以及「有幾多百分比嘅受試者成功達到里程碑」呀噉－如果個系統易用，應該會出現「多數受試者都能夠喺短時間之內搞掂」嘅情況；而且設計者喺觀察受試者嘅行為嘅過程裏面，仲能夠得到「用家犯錯嗰陣傾向犯乜嘢錯」嘅資訊，而呢樣資訊都幫到設計者度吓個系統嘅設計要點樣執[9]。可以睇埋心理實驗
• 易用度檢測（usability inspection）：指靠易用度專家用客觀方法親自做評估；例如認知走查法（cognitive walkthrough）係一種成日用嘅易用度檢測做法，當一個設計者用認知走查法嗰陣，佢首先要列出嗮「如果用家想要用隻軟件達到某樣效果，需要經過邊啲步驟？」，例如評估緊隻繪圖軟件，列出如果用家想要增加幅圖嘅光度需要先後撳邊個掣；然後 foreach 步驟，設計者都會問幾條問題：
1. 用家能唔能夠輕易睇得出要撳邊個掣？
2. 用家能唔能夠理解隻軟件對嗰個功能嘅描述？
• ... 等等。個設計者會一路做以上嘅嘢，做到評估嗮隻軟件嘅各種功能為止[10][11]

## 攷

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6. Liu, Yili; Feyen, Robert; and Tsimhoni, Omer. Queueing Network-Model Human Processor(QN-MHP): A Computational Architecture for Multitask Performance in Human-Machine Systems. ACM Transactions on Computer-Human Interaction. Volume 13, Number 1, March 2006, pages 37-70.
7. Lewis, J. R. (2006). Usability testing. Handbook of human factors and ergonomics, 12, e30.
8. Bastien, J. C. (2010). Usability testing: a review of some methodological and technical aspects of the method (PDF). International journal of medical informatics, 79(4), e18-e23.
9. Dumas, J. S., Dumas, J. S., & Redish, J. (1999). A practical guide to usability testing. Intellect books.
10. Blackmon, M. H., Polson, P. G., Kitajima, M., & Lewis, C. (2002, April). Cognitive walkthrough for the web (PDF). In Proceedings of the SIGCHI conference on human factors in computing systems (pp. 463-470).
11. Spencer, R. (2000, April). The streamlined cognitive walkthrough method, working around social constraints encountered in a software development company (PDF). In Proceedings of the SIGCHI conference on Human Factors in Computing Systems (pp. 353-359).