What it is
Confirmation bias is the tendency to favour information that confirms what we already believe and to interpret ambiguous evidence as supportive of the prior position. It operates at every stage of inquiry - in which sources are consulted, which questions are asked, and how the results are read. It is not limited to low-information situations: experts with strong prior views are often more susceptible, not less, because they have more sophisticated ways of explaining away contradictory data.
Where it shows up
In build-vs-buy decisions, confirmation bias is particularly acute when a technical leader or executive has already formed a view before the formal evaluation begins. The evaluation then functions as a ratification exercise: vendors who fit the preferred answer receive more favourable scrutiny, and technical objections to the preferred route are filed as edge cases. The decision record documents a process that was never genuinely open.
What Rubicon Probity does
When Rubicon Probity reviews a decision record at the Diagnose or Decide stage and finds that evidence is one-directional - that contradicting sources or objections are absent or dismissed without documented rebuttal - it raises a CAUTION flag and prompts a structured steelman exercise before the record is approved. The steelman must be documented in the record to proceed.
Detection questions
- Has the decision record included sources or arguments that actively contradict the preferred conclusion?
- Who in the process was assigned to make the strongest case against the current direction - and is their case documented?
- If the evidence were equally divided between supporting and contradicting your conclusion, which way would the decision go?