Digitization of education can be used to record and process teaching activities continuously in platform logs, learning analyses, and generative models, but there is still a lack of specific thresholds that determine whether a teaching activity is suitable for computation or whether it needs teacher leadership. The 312 identified teaching activities in this paper are divided into activity units; six dimensions of data observability, rule dominance, feedback immediacy, situational complexity, relationship sensitivity and ethical creation load are constructed, and a computable index and hybrid human-machine judgment framework are proposed. Based on the above results, content presentation and task practice fall within the fully computable range; formative evaluation is mostly auxiliary computable; collaborative learning is relatively conditional computable; and activities such as social-emotional support and ethical creation have shown obvious signs of being human-dominated. The weighted F1 of the hybrid framework for boundary recognition was 0.845, an increase of 10.0 percentage points over the regular baseline, and the residual risk dropped to 2.9%. The above research has offered an empirical basis for determining the limits of teaching activities and the integration model for teachers’ assessments, risk thresholds, and control transfers. The two basic ideas of this system are limited automation and auditable control; thus, it is difficult to determine precisely where and when these two factors will be affected.
