There is an increasing awareness of the social dimensions in the professionalidentity development of mathematics teachers. This paper reports on similaritiesand differences in how a novice teacher talks about good mathematics teachingand high-performing mathematics students at the time of her graduation and thenone year later. By analysing the social dimensions of the novice teachers’professional identity development these changes, often referred to asinconsistency and/or regression, can be understood as development in hermemberships in different kind of communities of practice.