Unit 4 · Lesson 1• 5 min
Source Hierarchy
Not all sources are equal. Judges weight them differently — know the pecking order.
Tier 1 — gold
Peer-reviewed studies (Nature, JAMA), official government data (CBO, GAO, BLS), and major nonpartisan think tanks (Brookings, RAND, Pew).
Tier 2 — solid
Major newspapers (NYT, WSJ, Reuters, AP), university research centers, established industry reports.
Tier 3 — risky
Opinion pieces, partisan think tanks (Heritage, CAP), blog posts. Use only with disclosure.
Tier 4 — don't
Wikipedia, random YouTube, AI-generated summaries without source check.
Quick Check
1. Strongest source for a policy stat:
Answer all 1 to check.
Takeaway
Tier 1 sources let you stop arguments cold. Tier 4 sources lose them.