The premise is that traditional web search, based on linking authority, is valuable - but some searches benefit greatly from displaying additional results prioritized by recency or social proxemity.
受限于链接权限的传统网络搜索同样是很有价值的，而一些搜索引擎却是从其它更新的结果中获利。
2
Its characteristics are subsystem can generate its own information and additional information given in the overall premise, specific "action" can be changed.