Global Terrorism Database Analysis

The GTD defines a terrorist attack as the threatened or actual use of illegal force and violence by a non-state actor to attain a political, economic, religious, or social goal through fear, coercion, or intimidation. Beyond requiring intentional violence by a non-state actor, coders record three additional criteria (a discernible aim, intent to coerce a wider audience, and action outside legitimate warfare), and analysts can filter to incidents meeting all criteria for stricter comparability.

The original incident records for 1993 were lost before the database was digitized, so the GTD has no event-level data for that year (only some aggregate estimates). Analysts must account for this gap in any time-series analysis, since naively treating 1993 as zero attacks would create a spurious dip and distort trend estimates.

The GTD focuses specifically on terrorism — non-state violence intended to intimidate a wider audience — with a long history back to 1970 and detailed tactic and target coding. ACLED codes a broader range of political violence and protest with near-real-time updates. For terrorism-specific questions and long trends the GTD is standard; for broad, current political-violence monitoring ACLED is often preferred. Their definitions and scope differ, so counts are not directly comparable.