Justification refers to a cognitive activity through which the validity of a mathematical statement is explained and communicated in order to convince or persuade others. Mathematical tasks function not only as vehicles for mathematical content but al...
Justification refers to a cognitive activity through which the validity of a mathematical statement is explained and communicated in order to convince or persuade others. Mathematical tasks function not only as vehicles for mathematical content but also as core classroom activities that shape students’ processes of understanding and applying concepts, as well as their ways of mathematical thinking. If the goal of mathematics education extends beyond checking conceptual understanding or procedural fluency to exploring the relationships among mathematical concepts and grasping their essential properties, then justification tasks that demand creativity and inquiry become indispensable. Such tasks must also be designed to be feasible for implementation in actual classroom settings. While formal justification tasks in textbooks often remain at the level of reproducing prescribed procedures and thus provide limited opportunities for exploratory learning, informal justification tasks hold the potential to foster students’ creative thinking and problem-solving. Accordingly, the provision of informal justification tasks that stimulate creativity and inquiry is necessary, and their practical applicability in classrooms must be ensured.
With the aim of examining teachers’ perceptions of the necessity of teaching informal justification tasks, this study investigated the noticing that secondary mathematics teachers engage in when judging the cognitive demand levels of textbook tasks in the Mean Value Theorem unit. The study was designed based on prior research on justification tasks, cognitive demand levels, and theoretical discussions on noticing. Teachers evaluated the cognitive demand levels of individual justification tasks presented in textbooks according to established definitions and articulated the grounds for their judgments. Based on these articulations, teachers further elaborated their perceptions regarding the necessity of teaching informal justification tasks. Teachers’ grounds for judging cognitive demand levels and their perceptions of the necessity of informal justification tasks were analyzed using the framework of noticing judgment criteria proposed by Weyers et al. (2024).
The results show that, in judging the cognitive demand levels of justification tasks, teachers engaged in noticing that integrated knowledge of content and teaching (KCT), specialized content knowledge (SCK), and knowledge of students (KCS). For formal justification tasks, unlike the researcher-agreed noticing, participating teachers tended to judge tasks as requiring higher levels of cognitive demand (PWC·DM Levels), focusing less on procedural reproduction (KCT) and more on conceptual connections (SCK) and students’ exploratory thinking (KCS). In contrast, when considering informal justification tasks, teachers demonstrated sociocultural noticing that carefully accounted for contextual factors such as classroom realities, textbook structure and authors’ intentions, and teacher and student levels. These findings indicate that teachers interpret tasks not only in terms of their cognitive structure but also through an integrated consideration of learners’ experiences and educational contexts.
Furthermore, teachers exhibited differing perceptions regarding the necessity and feasibility of teaching informal justification tasks. Some teachers argued against the need for additional instruction, citing the high cognitive demands already imposed by formal justification tasks, whereas others emphasized the necessity of informal justification tasks due to the procedural reproduction–oriented limitations of formal justification tasks. Overall, teachers’ noticing emerged as a multilayered reasoning process that synthesizes cognitive characteristics of tasks with sociocultural considerations. These results provide practical implications for enhancing the educational value of informal justification tasks and supporting their effective implementation in classroom practice.