PurposeThe purpose of this paper is to assess whether firefighters display different decision‐making biases: either a liberal bias to accepting information as true or a conservative bias to rejecting information, with the former carrying risk of “false alarm” errors and the latter of “misses”.Design/methodology/approachSituation awareness (SA) and decision‐making biases were examined in Fire and Rescue (FRS) “table‐top” and Breathing Apparatus (BA) training exercises. The former involved showing 50 operational FRS personnel a powerpoint presentation representing the drive‐to, views and information related to the incident. The BA study involved 16 operational FRS personnel entering a smoke‐filled training building in a search‐and‐rescue exercise. True/False answers to statements about the incidents were analysed by a signal‐detection‐type tool (QASA) to give measures of SA and bias.FindingsIn both studies, there were two groups showing different bias patterns (either conservative with risk of “miss” errors, or liberal with risk of “false alarms”) (p≤0.001), but not different SA (p>0.05).Research limitations/implicationsFuture work will involve more realistic training exercises and explore the consistency of individual bias tendencies over different contexts.Practical implicationsRisk in fireground decision making may be minimised by increasing awareness of individual tendencies to either conservative or liberal bias patterns and the associated risk of respectively making “miss” or “false alarm” errors.Social implicationsThe results may help to minimise fireground risk.Originality/valueThis is the first evidence to show firefighter decision bias in two different exercises.

This paper presents a model of situation awareness (SA) that emphasises that SA is necessarily built using a subset of available information. A technique (Quantitative Analysis of Situation Awareness - QASA), based around signal detection theory, has been developed from this model that provides separate measures of actual SA (ASA) and perceived SA (PSA), together with a feature unique to QASA, a measure of bias (information acceptance). These measures allow the exploration of the relationship between actual SA, perceived SA and information acceptance. QASA can also be used for the measurement of dynamic ASA, PSA and bias. Example studies are presented and full details of the implementation of the QASA technique are provided. Practitioner Summary: This paper presents a new model of situation awareness (SA) together with an associated tool (Quantitative Analysis of Situation Awareness - QASA) that employs signal detection theory to measure several aspects of SA, including actual and perceived SA and information acceptance. Full details are given of the implementation of the tool.