TaPSA Studies - Subject Categories
| Subject Categories | Number of Studies |
| Terrorism | 196 |
| Terrorist | 127 |
| September 11th | 72 |
| National Security | 63 |
| Weapons of Mass Destruction | 38 |
| Counterterrorism | 28 |
| Nuclear Terrorism | 24 |
| Bombing | 21 |
| Intelligence | 20 |
| World Trade Center | 20 |
| Al-Qaeda | 17 |
| Biological Terrorism | 13 |
| Uncategorized | 13 |
| Chemical Attack | 12 |
| Global Security | 11 |
| Anthrax | 10 |
| Homeland Security | 10 |
| Combating Terrorism | 9 |
| Hijacking | 8 |
| Terror | 8 |
| Very Small Categories | |
| Hate Crime | 7 |
| Ethnic Violence | 6 |
| Anti-terrorism | 5 |
| Riots | 5 |
| Riots | 3 |
| Arab Israeli conflict | 2 |
| Emergency Management | 2 |
| Emergency Response | 2 |
| International conflict | 2 |
| Surveillance | 2 |
| Emergency Management | 2 |
| Emergency Response | 2 |
| Surveillance | 2 |
| Anti-semitic | 1 |
| Bioterrorism | 1 |
| Domestic Preparedness | 1 |
| Organized Crime | 1 |
| Political Violence | 1 |
| Anti-semitic | 1 |
| Bioterrorism | 1 |
| Domestic Preparedness | 1 |
| Organized Crime | 1 |
| Political Violence | 1 |
| 52 | |
| Total Subject Categories |
43 |
295 studies: 42 unique subject keyword categories plus 'uncategorized' to account for studies missing subject keywords. 'Very small categories' comprised of subject keyword categories of less than 1%.