Wide and Shallow
Scanning ten options on one screen is far easier than tapping through four levels in a row. The former is one act of recognition; the latter is four decisions.
- 某个功能确实存在，但用户说从来没发现过
- 三级以下的页面几乎没有访问量
- 为了让导航看起来清爽，把东西一层层往里塞
The range of five to nine top-level items comes from the amount of information human short-term memory can handle effectively at once. Fewer than five usually means this level doesn't need to exist; more than nine and you should group them.
But the real point is depth. Every extra level loses a batch of people. Not because the click is effort, but because each level demands the user guess "which category does this belong to"—guess wrong once and they have to back out and start over.
What to do when you exceed nine
| 做法 | 什么时候用 |
|---|---|
| 分组但不加层 | 在同一屏内用分隔线或小标题把十几项分成三组。用户还是一眼扫完，没有多点一次 |
| 砍掉低频的 | 先看数据。一个月没人点的项，收进设置页比留在导航里好 |
| 加搜索 | 项数确实多且都需要（比如设置项），做一个能搜的入口比精心分类有效 |
| 改用矩阵 | 如果内容有多个属性、用户从不同角度找，用筛选代替分类 |
| 再加一层 | 最后才考虑。它看起来最整齐，代价也最大 |
How to fix it when it's already too deep
- Pull the high-frequency ones up. Find the third-level pages with the most traffic from the data, and give them a direct entry at the first or second level.
- Use search to flatten depth. Good search makes hierarchy irrelevant — the user jumps straight to the target. It's also the fallback when depth really can't be compressed any further.
- Build "Recent." Put where the user last was on the first screen, bypassing the hierarchy altogether.
- Merge levels that have only one child. A category with a single item under it is pure waste — just collapse the level.
Breadcrumbs don't solve the depth problem—they only solve "where am I." The user not getting lost on level four doesn't mean they're willing to tap four times every single time.