問32
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次の記述 a～d のうち, システム利用者にとって使いやすい画面を設計するために考慮するものだけを全て挙げたものはどれか。 a 障害が発生したときの修復時間 b 操作方法の覚えやすさ c プッシュボタンの配置 d 文字のサイズや色
平成26年度 春期 ITパスポート試験 問32
テクノロジ系情報デザイン › インタフェース設計
This question's explanation and your answers so far.
解説
問 32
Incorrectア
The combination a, b, c. Items b and c really are considerations for screen design, but item a, “The repair time when a failure occurs”, is an indicator of reliability and maintainability concerning MTTR (Mean Time To Repair), which is a different viewpoint from designing an easy-to-use screen. This option is also inappropriate because it leaves out item d, “The size and color of characters”, an important element of screen design.
Incorrectイ
The combination a, b, d. Including item a already makes it wrong (a is an availability indicator for operation and maintenance, not an item of screen design). In addition, this option excludes item c, “The layout of push buttons”, which is directly tied to operability, so it is incomplete as a list of screen-design considerations.
Incorrectウ
The combination a, c, d. Items c and d are correct as screen-design considerations, but this option is still wrong because it includes item a. Moreover, it leaves out item b, “How easy the operation method is to remember”, a representative aspect of usability, so it does not satisfy the question’s condition of listing only all of the items that should be considered.
- エ
正解 The correct answer is エ (b, c, d). The question asks which items should be considered when designing a screen that is easy for system users to use — in other words, pick only the items related to usability (ease of use). Item b, “How easy the operation method is to remember”, is about whether an operation you have learned once is easy to recall (memorability), a central element of usability. Item c, “The layout of push buttons”, is a screen-layout matter of arranging buttons along the flow of operation so that users do not press the wrong one; it directly affects operating efficiency and how few mistakes are made. Item d, “The size and color of characters”, relates to readability and visibility, and also to consideration for color vision characteristics and elderly users (accessibility); it is a basic item of screen design. In contrast, item a, “The repair time when a failure occurs”, is an indicator of reliability and maintainability — how quickly the system can be restored after it breaks (Mean Time To Repair, MTTR) — and has nothing to do with how the screen looks or how it is operated. Therefore the three items to consider in screen design are b, c and d, and エ, which lists only these, is correct.
ここがポイント
- The usability (ease of use) viewpoint: memorability, the layout of operating parts, visibility determined by character size and color — how easy the screen is to understand and how unlikely it is to cause operating errors when users work through it — these are the considerations for screen design. This is based on the idea of human-centered design.
- Repair time (MTTR) is an indicator of reliability and maintainability (availability), and it is measured on a different axis from usability. The key to this question is the ability to separate them: when the question is about ease of use, exclude any choice into which indicators of reliability, performance, or cost have slipped.
用語