AdaTutor: Adaptive Tutoring through Pedagogical Strategy Selection
Organizations: UNC Chapel Hill
Abstract
Effective tutoring requires determining not only what information to provide, but also which form of assistance to deliver. A tutor may address the same student error using various pedagogical strategies, adapting its approach as the interaction progresses. We introduce Comparative Pedagogical Supervision (CPS), a training framework to learn to select the optimal strategy and feedback for student learning. We evaluate CPS on math and science reasoning datasets. After five tutoring turns, CPS outperforms the strongest fixed-strategy baselines. The learned tutor transfers across datasets, and its strategy selection can also inform a separate API-based tutor.
Figures & tables
| Tutor | GSM8K | SVAMP | ScienceQA |
| Initial accuracy ( ) | 4.3 | 8.5 | 14.4 |
| Hint | 8.4 | 16.3 | 41.7 |
| Step scaffold | 32.6 | 32.8 | 51.8 |
| Explicit explanation | 48.9 | 31.3 | 50.0 |
| Worked example | 66.4 | 79.9 | 48.7 |
| Self-explanation | 7.3 | 16.5 | 40.6 |
| Dataset | Knowledge gap | Misconception | Mixed |
| GSM8K | |||
| SVAMP | |||
| ScienceQA |
| Dataset | Switch Rate (%) | Sessions (%) | Cond. MI (bits) |
| GSM8K | 62.3 | 79.2 | 0.17 |
| SVAMP | 54.3 | 67.3 | 0.08 |
| ScienceQA | 56.0 | 84.9 | 0.19 |
| Context | GSM8K | SVAMP | ScienceQA |
| Full history | 72.7 | 80.2 | 63.9 |
| Latest exchange | 72.8 | 78.1 | 65.4 |
| Latest student reply | 72.4 | 79.2 | 65.2 |
| Problem only | 50.6 | 72.3 | 66.7 |
| Dataset | Tutor | Fixed (%) | Own (%) |
| GSM8K | Prompt Selector | 2.9 | 4.7 |
| CPS | 37.0 | 39.1 | |
| SVAMP | Prompt Selector | 9.2 | 13.8 |
| CPS | 43.0 | 46.6 | |
| ScienceQA | Prompt Selector | 21.9 | 27.7 |
| CPS | 35.6 | 43.5 |
| Source dataset | GSM8K | SVAMP | ScienceQA |
| GSM8K | 72.7 | 78.7 | 49.1 |
| SVAMP | 75.5 | 82.5 | 51.1 |
| ScienceQA | 33.5 | 31.1 | 64.1 |
| Strongest fixed strategy | 66.4 | 79.9 | 54.0 |
| Tutor | Correction (%) | ||
| Step scaffold | 64.0 | 82.6 | 58.3 |
| Contrastive feedback | 72.9 | 82.6 | 58.3 |
| Prompt Selector | 68.0 | 87.9 | 70.9 |
| CPS selection + API | 73.3 | 89.9 | 75.7 |
Appendix figures & tables17 assets
Supplementary material from the paper’s appendix.
Appendix
| Problem: Mia has 6 marbles. Leo has twice as many. Each person receives 3 more marbles. How many marbles do they have altogether? | ||
| Initial student response: "Leo has marbles because ’twice as many’ means two more.” | ||
| Strategy | Definition | Illustrative tutor response |
| Minimal hint | Provide a brief cue directing attention to the relevant concept or relationship, allowing the student to independently determine the subsequent step. | "Focus on the word ’twice’ when comparing Leo’s marbles with Mia’s." |
| Step scaffold | Guide the next step by breaking it into smaller actions or providing a partial setup. | "First find Leo’s starting number of marbles. This is two groups of 6. What is ?" |
| Explicit explanation | Explain the relevant concept or rule and the reasoning behind it. | "’Twice as many’ means two equal groups of the original amount. Multiplication by two expresses this relationship." |
| Worked example | Demonstrate the relevant reasoning on an analogous problem with different values. Then, ask the student to apply the same method. | "Suppose Ana has 4 marbles and Ben has twice as many. Ben has . If each receives 1 more, their total is . Apply the same steps to Mia and Leo." |
| GSM8K | SVAMP | ScienceQA | |
| KCs in annotation library | 34 | 34 | TBC |
| KCs eligible for profile construction | 28 | 28 | TBC |
| Affected KCs per profile | 4 | 4 | TBC |
| Knowledge-gap profiles | 5 | 5 | 5 |
| Misconception profiles | 5 | 5 | 5 |
| Mixed profiles | 5 | 5 | 5 |
| Setting | GSM8K | SVAMP | ScienceQA |
| Training assignments | 2,934 | 3,000 | 8,624 |
| Validation assignments | 485 | 375 | 1,606 |
| Training SFT examples | 2,760 | 2,998 | 6,112 |
| Validation SFT examples | 469 | 378 | 1,111 |
| Training epochs | 3 | 4 | 4 |
| Maximum sequence length | 4,096 | 8,192 | 4,096 |
| Generation stage | Temperature |
| Initial student attempt | 0.0 |
| Tutor response | 0.3 |
| Student state update | 0.0 |
| Subsequent student response | 0.3 |
| Candidate-scoring student attempt | 0.3 |
| Setting | Value |
| LoRA rank | 16 |
| LoRA scaling factor | 32 |
| LoRA dropout | 0.05 |
| Learning rate | |
| Learning-rate schedule | Cosine decay |
| Warmup | 5% |
| Configuration | SFT examples | Validation |
| Outcome construction | ||
| Direct completion, | 773 | 88.55 |
| One student response followed by ten probes | 586 | 70.37 |
| Ten student responses with paired probes | 667 | 71.72 |
| Trajectory continuation | ||
| 773 | 88.55 | |
| Student reply | All KCs | Reached KCs | Full response | Answer agree | |
| Before tutoring | 270 | 78.1 | 63.7 | 58.1 | 100.0 |
| After tutor feedback | 180 | 81.8 | 76.1 | 61.1 | 97.8 |
| Criterion | Luna (%) |
| Requested strategy appears | 96.1 |
| Requested strategy is the main approach | 92.8 |
| Mathematically correct feedback | 95.0 |
| Correct final answer disclosed | 0.0 |
| Judgment | Luna | Human majority | Exact agreement |
| Student replies: 50 KCs with a resolved human majority | |||
| Consistent with assigned knowledge | 24/50 (48.0%) | 21/50 (42.0%) | 42/50 (84.0%) |
| Violates assigned knowledge | 7/50 (14.0%) | 10/50 (20.0%) | |
| Relevant step not reached | 19/50 (38.0%) | 19/50 (38.0%) | |
| Knowledge-state changes: 12 changed events | |||
| Feedback supports the change | 11/12 (91.7%) | 10/12 (83.3%) | 11/12 (91.7%) |
| Criterion | Human pairwise agreement (%) | Luna–human |
| Student knowledge-state labels | 41.8 | 0.74 |
| Feedback supports the change | 77.8 | 0.62 |
| Feedback addresses the changed KC | 94.4 | 1.0 |
| Requested strategy is the main approach | 93.3 | 0.83 |
| Mathematically correct tutor feedback | 86.7 | 0.64 |
| Feedback | Target KC changed |
| Relevant | 40/40 |
| Retry only | 0/40 |
| Irrelevant | 0/40 |
| Misaligned | 0/40 |
| Answer reveal | 0/40 |
| Student state | Accuracy (%) |
| Before feedback | 5.0 |
| After retry only | 5.0 |
| After irrelevant feedback | 5.0 |
| After misaligned feedback | 5.0 |
| After relevant feedback | 67.7 |
| After answer reveal | 5.0 |
Intelligent Tutoring Systems
Intelligent tutoring systems model learner knowledge and adapt instruction, practice, hints, and feedback to support learning.
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