How do AllSides and Ad Fontes rate major U.S. news outlets and what methodologies do they use?

1. What each chart claims to measure and why that matters

AllSides aims to show "left, center, right" placement of hundreds of outlets so readers can view opposing perspectives and break filter bubbles, and it concentrates on political bias rather than factual reliability in most of its public charting ^{[1] [2]}. Ad Fontes presents a two-dimensional chart that plots political bias on one axis and reliability/accuracy on the other, explicitly signaling that outlets can be biased but still reliable or vice versa, and it includes broadcast media as well as online sources ^{[5] [6]}.

2. How AllSides assigns ratings: volunteers, editorial review, and a five-point scale

AllSides places outlets on a five-point left-center-right scale using unpaid volunteer editors whose assessments are overseen by staff members intentionally selected to hold differing political biases; those crowd-sourced reviews are then augmented by editorial review and other processes described by the organization ^[1]. Independent guides note that AllSides' interactive chart does not incorporate a systematic accuracy score for each outlet the way Ad Fontes does and that it focuses primarily on written online content ^{[2] [6]}.

3. How Ad Fontes assigns ratings: trained analysts, balanced panels, and granularity

Ad Fontes employs many trained analysts from across the political spectrum who rate individual articles and segments on both bias and reliability; pieces are typically scored by “pods” that include a left, center and right reader to reduce single‑coder skew, and the company aggregates those granular content-level scores into source-level placements on the Media Bias Chart ^{[4] [3]}. Ad Fontes also samples material over multiple weeks to capture different news cycles and explicitly rates dimensions such as “expression,” “veracity” and “political position,” producing a more data‑driven, multi‑axis output ^{[4] [3]}.

4. Practical consequences for how outlets appear on the charts

Because AllSides emphasizes political leaning derived from crowd-sourced and editorial inputs, outlets are primarily categorized by left/center/right orientation and may not be differentiated by factual reliability on the chart itself ^{[1] [2]}. Ad Fontes’ methodology tends to cluster neutral outlets toward higher reliability and extreme sites toward lower reliability on the chart’s reliability axis, reflecting its content-sampling approach and its claim to measure both bias and accuracy ^{[7] [3]}.

5. Criticisms, limitations and possible agendas

Scholarly observers and media‑literacy guides acknowledge both projects' transparency about methods but warn that neither can produce an objective, final measurement of “bias” or “reliability,” and that snapshot ratings can change as outlets and news cycles evolve ^{[7] [4]}. Critics note potential sources of skew: AllSides’ reliance on volunteers and staff-curated oversight can import organizational viewpoints, and Ad Fontes’ human analysts—despite attempts at balance—still require subjective judgments even with balanced pods ^{[1] [4]}. Independent library guides stress the value of methodological transparency while urging users to supplement chart readings with source evaluation and other tools ^{[8] [2]}.

6. How to use the charts wisely

Treat AllSides as a map of perceived political leanings for primarily online outlets and Ad Fontes as a deeper content-analysis tool that tries to combine bias and accuracy across formats; both are helpful starting points for media literacy but should be read alongside direct source checking, awareness of the charts’ sampling periods, and an understanding that methodologies shape outcomes ^{[2] [3] [8]}. If a specific outlet’s placement is consequential, consult each project’s methodological notes and the sample pieces they used, because both organizations publish enough detail to let users see how particular ratings were derived ^{[3] [1]}.