# Activity Detection **Entity class:** Sensor And Multimodal-Fusion Layer concept **Activity Detection** is an observation or analytic method used to identify departures, recurring structure, or candidate signals for further assessment. Within a predictive graph, Activity Detection helps separate recorded evidence from the hidden state inferred from that evidence. ## Counterterrorism predictive-graph role The page records capability and analytic function. Any claim of a named operational deployment remains subject to the [[wiki/Counterterrorism Predictive Graph Evidence Ladder|evidence ladder]]. The analytic state should distinguish ground truth, observed evidence, inferred state, and predicted state. ## Relationships - **domain router:** [[wiki/Intelligence Fusion|Intelligence Fusion]]. - **ontology neighbors:** [[wiki/Event Detection|Event Detection]] and [[wiki/Anomaly Detection|Anomaly Detection]]. - **synthesis:** [[wiki/Counterterrorism Predictive Graph|Counterterrorism Predictive Graph]] and [[wiki/Predictive Intelligence Loop|Predictive Intelligence Loop]]. ## Sources - [IARPA — DIVA program (accessed September 23, 2026)](https://www.iarpa.gov/research-programs/diva) - [IARPA — AGILE technical overview (accessed September 23, 2026)](https://www.iarpa.gov/images/research-programs/AGILE/AGILE_ModSim_-_Final.pdf) **As of:** 2026-09-23