What does expectation bias refer to?

Expectation bias is when an investigator's prior beliefs, hypotheses, or expectations shape their interpretation of evidence or influence the conclusions they draw from their investigation. This can lead to a skewed analysis, as the investigator might unconsciously focus on data that supports their preconceived notions while overlooking or undervaluing evidence that contradicts them.

In the context of fire investigation, this bias can have significant implications. For instance, if an investigator is convinced that a fire was caused by arson, they may be more inclined to interpret ambiguous evidence in a way that reinforces this belief. This could lead to prematurely concluding a cause without thoroughly examining all possible factors or evidence present at a scene.

Conversely, the other options describe methodologies or mindsets that counteract this bias. Gathering data without preconceived notions, for instance, is crucial for objective investigation but does not encapsulate the essence of expectation bias itself. An objective approach to experimental design also promotes neutrality in conclusion-drawing, while relying solely on factual data without interpretation misses the component where expectation bias comes into play, as interpretation is often where such bias is introduced.