本文是 iOS Human Interface Guidelines 中 Design Principles 的中文譯文。純手工翻譯，加深自己理解。
Aesthetic Integrity
Aesthetic integrity represents how well an app’s appearance and behavior integrate with its function. For example, an app that helps people perform a serious task can keep them focused by using subtle, unobtrusive graphics, standard controls, and predictable behaviors. On the other hand, an immersive app, such as a game, can deliver a captivating appearance that promises fun and excitement, while encouraging discovery.
整體美學
整體美學表示了一個應用的呈現和功能需要融為一體。例如，用于完成正式工作的應用，可以通過低調精妙的圖片、標準化的控件、可預測的交互行為，幫助人們聚焦在工作本身。另一方面，提供沉浸式體驗的應用，例如游戲，在鼓勵用戶探索的同時，會提供有吸引力的外觀，從而帶來快樂和刺激。
Consistency
A consistent app implements familiar standards and paradigms by using system-provided interface elements, well-known icons, standard text styles, and uniform terminology. The app incorporates features and behaviors in ways people expect.
一致性
風格一致性是指，通過使用系統提供的接口、熟悉的圖標、標準的文本樣式、統一的用辭，來實現熟悉的標準和樣式。應用中包含符合用戶期望的功能和行為。
Direct Manipulation
The direct manipulation of onscreen content engages people and facilitates understanding. Users experience direct manipulation when they rotate the device or use gestures to affect onscreen content. Through direct manipulation, they can see the immediate, visible results of their actions.
直接操控
直接操控屏幕上的內容，可以幫助人們進行理解。當用戶旋轉設備或者使用手勢來影響屏幕內容時，用戶可以體驗到直接操控的感覺，他們可以立即看到自己動作所帶來的可視化結果。
Feedback
Feedback acknowledges actions and shows results to keep people informed. The built-in iOS apps provide perceptible feedback in response to every user action. Interactive elements are highlighted briefly when tapped, progress indicators communicate the status of long-running operations, and animation and sound help clarify the results of actions.
反饋
反饋可以確認操作，使人們感知到結果。iOS自帶應用提供可以感知的反饋，來響應每個用戶的行動。這些有助于說明用戶行動的結果：交互元素點擊瞬間高亮顯示、進度指示來顯示耗時操作的狀態、動畫和音效。
Metaphors
People learn more quickly when an app’s virtual objects and actions are metaphors for familiar experiences—whether rooted in the real or digital world. Metaphors work well in iOS because people physically interact with the screen. They move views out of the way to expose content beneath. They drag and swipe content. They toggle switches, move sliders, and scroll through picker values. They even flick through pages of books and magazines.
隱喻
當應用中的虛擬對象和操作，能用熟悉的體驗來形象比喻時，無論這些體驗是基于現實世界或者數字世界，用戶會很快理解如何使用。隱喻在iOS上非常有效，因為用戶通過屏幕來進行互動。用戶移動視圖來查看更多內容、拖曳和滑動內容、點擊開關、移動滑條、滾動滾盤、快速翻頁。
User Control
Throughout iOS, people—not apps—are in control. An app can suggest a course of action or warn about dangerous consequences, but it’s usually a mistake for the app to take over the decision-making. The best apps find the correct balance between enabling users and avoiding unwanted outcomes. An app can make people feel like they’re in control by keeping interactive elements familiar and predictable, confirming destructive actions, and making it easy to cancel operations, even when they’re already underway.
用戶控制
在iOS中，是人來進行控制，而不是應用。應用可以建議一系列的操作，或者對危險的后果進行警告，但是讓應用來做決定通常都是錯誤的。最好的應用在用戶操作和避免錯誤結果之間進行平衡。通過使用熟悉和行為可預測的交互元素、對重要操作進行確認、更容易取消操作即便已在執行中，應用就可以讓人感覺到他們在進行控制。
參考：
[1] iOS Design Principles
