What It Is
Bias by commission occurs when journalists actively include misleading, irrelevant, or contextually inappropriate information that distorts audience understanding. While omission bias involves leaving things out, commission bias involves adding things that mislead.
How It Works
Including technically true but misleading information can shape perception as effectively as false claims. Adding irrelevant details can imply connections that don’t exist or distract from what matters.
Real-World Example
Misleading by inclusion:
A story about a person’s policy proposal includes extensive coverage of an unrelated personal controversy.
- Bias by commission: The personal information is technically accurate but irrelevant to evaluating the policy, and its inclusion poisons audience reception
- Appropriate inclusion: Personal information is relevant to the story (e.g., conflict of interest) and clearly connected
Or: Mentioning a defendant’s prior arrests (but not convictions) for unrelated matters, creating an impression of guilt.
How to Spot It
- Question relevance - Why is this detail included?
- Consider the impression - What does this information suggest?
- Check for connections - Is the implied connection supported?
- Note emotional loading - Does included detail inflame without informing?
- Ask what’s proven - Is this allegation, speculation, or established fact?
Why It Matters
Bias by commission can be harder to detect than false claims because the included information is technically accurate. Understanding this bias helps you evaluate not just whether information is true but whether it’s relevant and appropriately contextualized.
Related Bias Types
- Omission Bias - Leaving out key information
- Spin Bias - Subtle interpretive framing
- Framing Bias - Story angle and presentation