Collective teacher efficacy (CTE) encompasses perceptions of shared beliefs in collective power and coordinated actions to achieve desired results (Bandura, 2000). It is one of the strongest factors influencing student success. However CTE can be disrupted by significant change to curricula, particularly if policy lacks clarity around enacting new requirements, or incorrectly assumes that teachers possess requisite skills and knowledge. As well as the standard use of quantitative models, which measure relationships between CTE and other variables, there is also a need for qualitative analyses to deeply explore how CTE is experienced by teachers during such periods of change. Our research investigates how CTE is shaped during changes to curricula, as teachers in an Australian secondary school embed critical thinking across key learning areas (KLAs) in a new national curriculum (ACARA, 2014). This paper presents preliminary findings from semi-structured interviews which were analysed using the Systemic Functional Linguistic (SFL) interpersonal resource of Appraisal (Martin & White, 2005). Appraisal enables a systematic description of the evaluative language choices made (such as emotion, judgement, or appreciation) to reveal patterns of social behaviour that become apparent as teachers reflected on their experience. Through Appraisal analysis the complexities of CTE allow insight into the social alignments and collective attitudes that develop during a time of significant change. This research builds on current understanding of approaches to CTE by foregrounding the teacher’s voice and the way differing values connect teachers during periods where disruption and readjustment can impact on their sense of CTE.