LEAST BIASED
These sources have minimal bias and use very few loaded words (wording that attempts to influence an audience by appeals to emotion or stereotypes). The reporting is factual and usually sourced. These are the most credible media sources. See all Least Biased Sources.
- Overall, we rate the Berkeley IGS Poll as Least Biased based on polling that minimally favors Democrats. We also rate them as High Factual pollsters based on an A− rating in predictive polling.
Detailed Report
Bias Rating: LEAST BIASED (-0.7)
Factual Reporting: HIGH (1.5)
Country: USA
MBFC’s Country Freedom Rating: MOSTLY FREE
Media Type: Organization/Foundation
Traffic/Popularity: Minimal Traffic
MBFC Credibility Rating: HIGH CREDIBILITY
History
The Berkeley Institute of Governmental Studies (IGS) Poll is conducted by the Institute of Governmental Studies at the University of California, Berkeley. According to its about page, IGS supports research, public service training, and public discourse on California and American politics. The Berkeley IGS Poll is a periodic survey measuring California public opinion on politics and public policy and is widely disseminated for scholarly and public use.
Read our profile on the United States media and government.
Funded by / Ownership
The Berkeley IGS Poll is operated by the University of California, Berkeley, a public university. Funding derives from university resources and research-related support. The poll is directed by Mark Di Camillo and is affiliated with the California Digital Library and UC Berkeley Dataverse.
Analysis / Bias
The Berkeley IGS Poll conducts statewide public opinion surveys and publishes media releases and tabulations of its findings. It does not publish general political news or ideological commentary, limiting content to poll-related releases and methodological documentation.
Polling bias is assessed using Silver Bulletin’s mean-reverted bias metric. For the Berkeley IGS Poll, the mean-reverted polling bias is −0.32, indicating a very slight Democratic lean. Under MBFC’s calibrated polling bias scale, a mean bias between 0.0 and 0.5 corresponds to a polling bias score of −1. Polling bias accounts for 70% of the final bias score, while editorial bias accounts for 30%.
Because the organization does not publish ideological commentary or political news beyond reporting its polling data, editorial bias is assessed at 0.
Applying MBFC’s weighted formula:
(−1 × 0.70) + (0 × 0.30) = −0.7
Based on MBFC’s bias classification scale, a final score of −0.7 places the Berkeley IGS Poll in the Least Biased category.
Factual reporting is rated High based on a Silver Bulletin grade of A−, indicating solid predictive accuracy and good methodological performance.
Failed Fact Checks
- None in the Last 5 years
Overall, we rate the Berkeley IGS Poll as Least Biased based on polling that minimally favors Democrats. We also rate them as High Factual pollsters based on an A− rating in predictive polling. Updated (02/27/2026)
Source: https://igs.berkeley.edu/research/berkeley-igs-poll
Last Updated on February 27, 2026 by Media Bias Fact Check
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Left vs. Right Bias: How we rate the bias of media sources