Marcia Bates describes four modes of getting information, ordered by how much effort a person invests. Context awareness is the least effortful, people absorb information just by being present in their environment, without seeking anything at all. Monitoring requires directing some attention to specific sources, a "back-of-the-mind alertness", without actively searching. Seeking known items is a goal-directed activity: the person knows what they want and pursues it deliberately. Exploratory seeking, or browsing, is the most effort-intensive mode, especially when it becomes exhaustive research.
Bates summarized the distinction memorably: monitoring and directed searching are how we find information we know we need, while browsing and awareness are how we find information we didn't know we needed.
Not every information need shows up as a search query. Some of the most valuable IA decisions, what to surface on a homepage, what to put in a newsletter, are designed for context awareness and monitoring, not active search.
1: Context awareness. She absorbed information passively, simply by being present, with no intent to seek anything.
2: Monitoring. A subscribed alert checked periodically is exactly the "back-of-the-mind alertness" Bates describes, without active searching.
3: Seeking known items. She knows precisely what she wants and pursues it directly, the definition of a known-item, goal-directed search.
4: Exploratory seeking. No goal, sustained browsing, following whatever looks interesting: this is browsing at its most effort-intensive end of the spectrum.
A digest email or alert subscription supports monitoring well, situation 2, because it does the work of periodic checking on the user's behalf. But that same feature would do nothing for situation 1: the break room employee isn't subscribed to anything and isn't checking anything on purpose. She's simply present. No opt-in feature can reach someone who never opted in, reaching her requires passive, ambient placement, not a subscription mechanism.The larger point Bates makes explicit: monitoring and known-item search serve information people already know they need, while awareness and browsing surface information people didn't know they needed. A single feature almost never serves both halves of that divide well, which is why real information spaces typically need a search bar for known items and a very different kind of design, enticing links, previews, curated homepages, for exploratory browsing and ambient awareness.