Intended Use
TACTutor generates the next teacher response in an ongoing English-learning
conversation. It is intended for research on pedagogically adaptive dialogue,
including feedback, guided revision, clarification, and learner-supportive
conversation management.
The model is a research artifact, not a replacement for a qualified teacher.
Outputs should be reviewed before use in high-stakes educational settings.
Loading
from transformers import AutoModelForCausalLM, AutoTokenizer model_id = "Taxonomy-Aligned-Conversational-Tutor/TACTutor"tokenizer = AutoTokenizer.from_pretrained(model_id, trust_remote_code=True)model = AutoModelForCausalLM.from_pretrained( model_id, torch_dtype="auto", device_map="auto", trust_remote_code=True,)
One prompt used in our evaluation is:
You are an expert ESL tutoring teacher. Your job is to write the next teacher response in an ongoing teacher-student chat.Respond naturally and pedagogically. Do not explain your reasoning. Do not mentiontaxonomy labels, rubrics, or evaluation criteria.
Pass this instruction as the system message, followed by the dialogue history,
and use the tokenizer's chat template to construct the model input.
Evaluation
On the 78-item TACTBench diagnostic benchmark, the selected checkpoint achieved:
Table with columns: Metric, Score| Metric | Score |
|---|
| TACT Overall | 0.832051 |
| Accept | 0.871795 |
| Leak | 0.025641 |
| Off-task | 0.025641 |
The scores above were measured before five representative benchmark examples
were released. Those public examples are demonstration data and should be
excluded from future hidden-set scoring.
Training Data and Limitations
The post-training data are derived from authentic English tutoring dialogue and
taxonomy-guided augmentation. The complete training corpus and hidden benchmark
are not included in this repository. Five short full-context demonstration
examples are available in the companion dataset repository.
The source dialogue is derived from the Teacher-Student Chatroom Corpus version
2 (TSCC v2), which is governed by its own user agreement. This model may produce
incorrect, overly explicit, or contextually inappropriate tutoring responses,
and its behavior outside English-language tutoring has not been established.
Citation
Please cite the following paper when using TACTutor:
@article{yang2026tact, title = {TACT: Taxonomy-Aligned Post-Training for Pedagogically Adaptive English Tutoring}, author = {Yang, Dongjie and Lin, Siyan and Shen, Leixian and Sheng, Rui and Qu, Huamin and Chen, Zixin}, year = {2026}}
License
The model weights are released under the Apache License 2.0. The TSCC-derived
source data remain subject to the TSCC user agreement and are not redistributed
with the model weights.