A measure of teacher identity specific to teachers of mathematics was developed and assessed, the teacher of mathematics identity (ToMI) scale. A sample of teachers was recruited from a state-based mathematics association to complete an online survey including items based on the theories of Mead, Erikson, and Wenger. The subscales of belonging to a mathematics community, self-efficacy as a teacher of mathematics, and enthusiasm to be a teacher of mathematics were derived using exploratory factor analysis (n = 301) and then confirmed with confirmatory factor analysis (n = 311) with randomly allocated independent subsamples. These subscales were related and, when combined to form a single factor, explained a substantial proportion of the variance in the data, suggesting that the ToMI scale can be used as three separate subscales or combined to form a single overarching construct. Overall, ToMI and subscale scores were used in the validation process. Tests of validity were run in the two randomly allocated subsamples independently, allowing for replication of findings. As predicted based on the literature, the ToMI scale and subscales were related to the number of years teaching mathematics, the size of teacher of mathematics network accessed by teachers, and participation in mathematics-specific self-directed professional learning and wellbeing while teaching mathematics. These results reveal this initial iteration of the ToMI scale as valid concerning the underlying teacher identity theory, providing an important research avenue to pursue our understanding and development of effective teachers of mathematics.

开发和评估了数学教师特有的教师身份衡量标准，即数学教师身份 (ToMI) 量表。从州数学协会招募了一批教师样本，以完成一项在线调查，其中包括基于米德、埃里克森和温格理论的项目。属于数学共同体的分量表、作为数学教师的自我效能感和作为数学教师的热情使用探索性因子分析得出（n  = 301），然后通过验证性因子分析（n = 311) 具有随机分配的独立子样本。这些子量表是相关的，当组合成一个单一因素时，解释了数据中很大一部分方差，表明 ToMI 量表可以用作三个独立的子量表或组合形成一个单一的总体结构。总体而言，在验证过程中使用了 ToMI 和分量表分数。有效性测试在两个随机分配的子样本中独立运行，允许复制发现。正如根据文献预测的那样，ToMI 量表和子量表与数学教学年数、教师访问的数学教师网络的规模以及在数学教学中参与数学特定的自主专业学习和幸福感有关。