What is expectation bias in the context of an investigation?

Expectation bias refers to the phenomenon where preconceived notions and beliefs of an investigator influence their analysis and conclusions during an investigation. In the context of fire investigation, this means that if an investigator begins the process with a certain theory or assumption about the origin or cause of a fire, their interpretation of evidence may lean towards supporting that theory. This can lead to a skewed understanding of the evidence, as the investigator may unconsciously favor data that confirms their initial thoughts and overlook evidence that contradicts them.

Understanding expectation bias is crucial as it highlights the importance of maintaining objectivity and openness throughout an investigation. Investigators must actively work to mitigate this bias to ensure a thorough analysis of all available evidence, avoiding premature conclusions that could affect the outcome of the inquiry. This reinforces the need for comprehensive training and methodologies that promote unbiased data collection and analysis.