Formulating Hypotheses and Lines of Investigation

Formulating working hypotheses from the first available evidence gives the investigation direction instead of collecting data indiscriminately in the hope that something relevant shows up. In practice, a good hypothesis is specific and testable, such as assuming the initial access happened through an employee's leaked credentials, instead of a vague idea like "there was an external attack". Keeping several lines of investigation open in parallel, instead of committing to a single hypothesis from the start, avoids confirmation bias, where the investigator only looks for evidence that supports their first intuition and ignores data that contradicts it. As new evidence appears, hypotheses must be actively discarded or adjusted, and documenting that discarding process is as valuable as documenting the final confirmed hypothesis, because it demonstrates methodological rigor in any later review of the case.