Shared blackboard
Several agents read and write one shared state instead of messaging each other.
Shape：Shared store plus several independent readers and writers
When to use it
When intermediate results must be shared and agents progress out of step. Task boards, shared memory and state machines all fall here.
When not to
Frequent writes needing strict ordering. A blackboard offers no transactional semantics; you must build them.
How it fails
- Concurrent write conflicts: two agents edit the same entry, the later write wins, and neither gets an error.
- State contamination. Bad data written by one agent is taken as fact by the others and elaborated — wrong memories reinforce themselves.
- No attribution. A conclusion on the board cannot be traced to who wrote it, when, or from what.
Design notes
Every write carries author, timestamp and source pointer; use optimistic locking (compare-and-set on a revision) rather than last-write-wins. Separate read from write: anyone may read, writes are scoped.
Origin
黑板架構有明確的學術源流，但本輪未抓取到可直接引用的一手來源；按證據標准不填日期。