EmotiQ: A Quantum Residual Specialist Framework for Text Emotion Classification
Organizations: Department of Computer Science, Earlham College, Richmond, IN, USA · Department of Computer Science, Eastern Michigan University, Ypsilanti, MI, USA
Abstract
Emotion classification from text is challenging because many affective states are distinguished by subtle linguistic signals and semantically overlapping boundaries. We investigate whether compact quantum modules can serve as targeted residual specialists that assist traditional classifiers on difficult emotion decisions. We introduce EmotiQ, a residual specialist framework for text emotion classification using a frozen transformer classifier as the primary decision maker, identifies challenging emotion boundaries from validation behavior, and trains boundary specialists, including quantum encodings, data re-uploading specialists, prototype and fidelity specialists, and kernel-based specialists. Specialists are permitted to intervene only when they satisfy validation-based admission criteria. We evaluate the framework across six text emotion classification datasets and establish traditional model baselines. Experimental results show that the admitted EmotiQ policy improves mean macro-F1 metrics over the baseline, and achieves positive gains on five of six datasets. Among the quantum components, ZZ interaction feature maps are the most consistently effective, yielding a mean macro-F1 improvement of +0.0030 and positive gains on four datasets. These findings suggest that current quantum NLP methods can be deployed as residual specialists that provide localized improvements under strong classical supervision.
Figures & tables
| Dataset | Train | Val. | Test | Labels |
|---|---|---|---|---|
| AI-Roadmap | 2,781 | 309 | 773 | 6 |
| BRIGHTER | 1,140 | 92 | 2,186 | 6 |
| Bulpara-8 | 26,276 | 3,320 | 3,330 | 8 |
| Emotion20 | 57,308 | 6,368 | 15,919 | 20 |
| Super Emotion | 431,371 | 53,824 | 56,339 | 7 |
| Tanaos-8 | 8,196 | 911 | 2,277 | 8 |
| Best model in family | Configs. | Mean F1 |
|---|---|---|
| Frozen DistilBERT + logistic regression | 4 | 0.608 |
| Word + character TF-IDF + linear SVM | 1 | 0.583 |
| Character TF-IDF + linear SVM | 1 | 0.582 |
| Word TF-IDF + Ridge | 10 | 0.544 |
| SVD-96 + RBF SVM | 10 | 0.424 |
| Encoding | Mean F1 | Mean F1 | Improved |
|---|---|---|---|
| features | 0.582 | +0.0030 | 4/6 |
| kernel SVM | 0.582 | +0.0025 | 3/6 |
| Angle-trigonometric | 0.580 | +0.0013 | 3/6 |
| Fidelity prototypes | 0.573 | 2/6 |
| Head | Policy | Mean F1 | Mean F1 | Improved |
|---|---|---|---|---|
| Classical | Gated top- | 0.585 | +0.0055 | 5/6 |
| RFF | Gated top- | 0.581 | +0.0017 | 3/6 |
| Quantum | Gated top- | 0.581 | +0.0015 | 4/6 |
| Classical | Standalone | 0.331 | 0/6 | |
| RFF | Standalone | 0.343 | 0/6 | |
| Quantum | Standalone | 0.341 | 0/6 |
| Mechanism | Mean F1 | Improved | Nonneg. |
|---|---|---|---|
| Best encoding ( features) | +0.0030 | 4/6 | 4/6 |
| Best ambiguity head (classical) | +0.0055 | 5/6 | 5/6 |
| Pair quantum specialist | +0.0036 | 5/6 | 5/6 |
| Full admitted EmotiQ | +0.0076 | 5/6 | 6/6 |
| Dataset | Macro-F1 | F1 | Active pairs |
|---|---|---|---|
| AI-Roadmap | 0.446 | +0.0058 | 2 |
| BRIGHTER | 0.160 | +0.0217 | 2 |
| Bulpara-8 | 0.513 | 0.0000 | 0 |
| Emotion20 | 0.657 | +0.0034 | 2 |
| Super Emotion | 0.489 | +0.0069 | 2 |
| Tanaos-8 | 0.783 | +0.0077 | 3 |
| Policy / specialist | Mean F1 | Mean F1 | Improved |
|---|---|---|---|
| Admitted / selected | 0.508 | +0.0076 | 5/6 |
| Unrestricted / re-uploading | 0.500 | 1/6 | |
| Unrestricted / angle | 0.500 | 4/6 | |
| Unrestricted / shared re-uploading | 0.497 | 2/6 | |
| Unrestricted / kernel | 0.479 | 1/6 | |
| Unrestricted / prototype | 0.475 | 1/6 |
| Dataset | Emotion boundary | Specialist | F1 | Precision | Harm | Decision |
|---|---|---|---|---|---|---|
| AI-Roadmap | anger vs. disgust | Angle | +0.0107 | 0.75 | 0.00 | Accept |
| Tanaos-8 | joy vs. excitement | Shared re-uploading | +0.0130 | 1.00 | 0.00 | Accept |
| BRIGHTER | joy vs. sadness | Re-uploading | +0.0309 | 0.67 | 0.33 | Reject: harm |
| Bulpara-8 | joy vs. trust | Polynomial kernel | +0.0134 | 0.80 | 0.20 | Reject: harm |