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Study flow and cohort
Recruitment, screening, written consent, class-level allocation, outcome-specific completion, and the final analysis set across baseline (T0), immediate post-test (T1), and follow-up (T2) are summarized in Figure 1. In the pilot implementation, 4 intact classes comprising 48 learners were allocated at the class level, with 2 classes assigned to task-based learning (TBL, n = 24) and 2 classes assigned to Presentation-Practice-Production (PPP, n = 24). At T0, all 48 learners completed the oral discourse completion task (ODCT), questionnaire measures, and the filmed role-play task. At T1, 47 learners completed the ODCT and questionnaires, and 46 analyzable role-play recordings were retained after exclusion of 1 recording because of severe background noise. At T2, 45 learners completed the ODCT and questionnaires, and 44 analyzable role-play recordings remained after excluding 1 additional recording due to irrecoverable speaker overlap. Participant-level de-identified longitudinal data underlying these representative outcomes are provided in Supplementary File 4.
Baseline characteristics
Baseline demographic and language-learning characteristics are presented in Table 1. Because only 4 intact classes were allocated in this pilot, these values are reported to describe cohort composition rather than establish group equivalence. The two conditions were broadly similar in age, gender distribution, Chinese Proficiency Test level, and prior exposure to Chinese-speaking environments, although class-level and teacher-related confounding cannot be ruled out in this design.
Pragmatic performance outcomes
Pragmatic performance outcomes across T0, T1, and T2 are presented in Table 2. For the ODCT composite score (0-25), both groups scored higher at T1 than at T0, with a larger gain in the TBL arm than in the PPP arm (+5.04 vs. +2.50). The TBL group increased from 12.46 ± 3.21 at T0 to 17.50 ± 3.18 at T1 and remained above baseline at 16.92 ± 3.37 at T2. The PPP group increased from 11.98 ± 2.92 at T0 to 14.48 ± 3.63 at T1 and remained above baseline at 13.82 ± 3.70 at T2. This trajectory is shown in Figure 2.
A similar pattern was observed for the filmed role-play assessment. In the TBL arm, the mean role-play score increased from 13.10 ± 2.86 at T0 to 17.84 ± 3.04 at T1 and was 17.10 ± 3.12 at T2. In the PPP arm, the corresponding values were 12.88 ± 2.79, 15.26 ± 3.08, and 14.60 ± 3.17. The increase from T0 to T1 was larger in the TBL arm than in the PPP arm (+4.74 vs. +2.38). Intercultural sensitivity also increased in both groups. In the TBL arm, the total score rose from 48.96 ± 6.19 at T0 to 54.52 ± 6.36 at T1 and remained at 53.60 ± 6.28 at T2. In the PPP arm, the corresponding values were 48.67 ± 7.39, 51.77 ± 8.09, and 50.74 ± 7.96. The increase from T0 to T1 was larger in the TBL arm than in the PPP arm (+5.56 vs. +3.10). Given the pilot design and the small number of clusters, these between-group differences should be interpreted cautiously.
Supportive speech and questionnaire outcomes
Supportive speech and questionnaire outcomes across T0, T1, and T2 are presented in Table 3. Across occasions, both groups showed improvement from baseline to post-test on the supportive outcomes, with the task-based learning (TBL) arm generally showing larger observed changes than the Presentation-Practice-Production (PPP) arm. Words per minute increased in both groups, whereas silent pauses and the percentage of T-units containing at least one morpho-syntactic error decreased. Mean clause length also increased across occasions in both conditions.
Speaking anxiety, indexed using the short-form Foreign Language Classroom Anxiety Scale, decreased from T0 to T1 in both groups and remained below baseline at T2. The reduction was larger in the TBL arm than in the PPP arm. These trajectories are shown in Figure 3.

Figure 1: Study flow and class-level allocation. CONSORT-style diagram summarizing screening, written consent, class-level allocation to task-based learning (TBL) or Presentation-Practice-Production (PPP), and occasion-specific completion of the oral discourse completion task, filmed role-play, questionnaires, and analyzable speech recordings at baseline (T0), immediate post-test (T1), and follow-up (T2), including exclusions and attrition. Please click here to view a larger version of this figure.

Figure 2: Oral discourse completion task performance across occasions. Oral discourse completion task (ODCT) composite scores (0-25) at baseline (T0), immediate post-test (T1), and follow-up (T2) for task-based learning (TBL) and Presentation-Practice-Production (PPP). Points represent group means, and lines connect the three assessment occasions. Please click here to view a larger version of this figure.

Figure 3: Supportive outcome profiles across occasions. Profiles of supportive outcomes for task-based learning (TBL) and Presentation-Practice-Production (PPP) across baseline (T0), immediate post-test (T1), and follow-up (T2), including words per minute, silent pauses of 0.25 s or longer per minute, percentage of T-units containing at least one morpho-syntactic error, mean clause length, and short-form Foreign Language Classroom Anxiety Scale scores. FLCAS-S, short-form Foreign Language Classroom Anxiety Scale. Please click here to view a larger version of this figure.
| Characteristic | n = 24 TBL | n = 24 PPP |
| Age, years, mean ± SD | 22.13 ± 1.83 | 22.38 ± 2.43 |
| Female, n (%) | 13 (54.2) | 12 (50.0) |
| Male, n (%) | 11 (45.8) | 12 (50.0) |
| Chinese Proficiency Test level 3, n (%) | 9 (37.5) | 9 (37.5) |
| Chinese Proficiency Test level 4, n (%) | 13 (54.2) | 12 (50.0) |
| Chinese Proficiency Test level 5, n (%) | 2 (8.3) | 3 (12.5) |
| Prior residence in a Chinese-speaking environment within the previous 2 years, n (%) | 4 (16.7) | 5 (20.8) |
| Years of prior formal Chinese study, mean ± SD | 2.4 ± 0.9 | 2.5 ± 1.0 |
Table 1: Baseline characteristics by instructional condition. Baseline (T0) demographic and language-learning characteristics of learners in the task-based learning (TBL) and Presentation-Practice-Production (PPP) conditions.
| Outcome Measure | Group | n | Mean ± SD | n | Mean ± SD | n | Mean ± SD | Δ | Δ |
| (T0) | (T0) | (T1) | (T1) | (T2) | (T2) | (T1-T0) | (T2-T0) |
| ODCT composite (0–25) | TBL | 24 | 12.46 ± 3.21 | 24 | 17.50 ± 3.18 | 23 | 16.92 ± 3.37 | 5.04 | 4.46 |
| ODCT composite (0–25) | PPP | 24 | 11.98 ± 2.92 | 23 | 14.48 ± 3.63 | 22 | 13.82 ± 3.70 | 2.5 | 1.84 |
| Filmed role-play score (0–25) | TBL | 24 | 13.10 ± 2.86 | 23 | 17.84 ± 3.04 | 22 | 17.10 ± 3.12 | 4.74 | 4 |
| Filmed role-play score (0–25) | PPP | 24 | 12.88 ± 2.79 | 23 | 15.26 ± 3.08 | 22 | 14.60 ± 3.17 | 2.38 | 1.72 |
| Intercultural Sensitivity Scale (24–120) | TBL | 24 | 48.96 ± 6.19 | 24 | 54.52 ± 6.36 | 23 | 53.60 ± 6.28 | 5.56 | 4.64 |
| Intercultural Sensitivity Scale (24–120) | PPP | 24 | 48.67 ± 7.39 | 23 | 51.77 ± 8.09 | 22 | 50.74 ± 7.96 | 3.1 | 2.07 |
Table 2: Pragmatic performance and intercultural sensitivity across occasions. Oral discourse completion task composite scores, filmed role-play scores, and Intercultural Sensitivity Scale scores at baseline (T0), immediate post-test (T1), and follow-up (T2) for the task-based learning (TBL) and Presentation-Practice-Production (PPP) conditions.
| Outcome | Direction | Group | n at T0 | T0 mean ± SD | n at T1 | T1 mean ± SD | n at T2 | T2 mean ± SD | Δ | Δ |
| (T1–T0) | (T2–T0) |
| Words per minute | Higher better | TBL | 24 | 85.0 ± 11.6 | 23 | 104.3 ± 13.1 | 22 | 100.6 ± 12.8 | 19.3 | 15.6 |
| Words per minute | Higher better | PPP | 24 | 85.1 ± 10.9 | 23 | 95.0 ± 12.2 | 22 | 92.4 ± 11.9 | 9.9 | 7.3 |
| Silent pauses ≥0.25 s per minute | Lower better | TBL | 24 | 16.1 ± 3.4 | 23 | 11.4 ± 2.9 | 22 | 12.1 ± 3.0 | −4.7 | −4.0 |
| Silent pauses ≥0.25 s per minute | Lower better | PPP | 24 | 15.9 ± 3.1 | 23 | 13.5 ± 2.8 | 22 | 13.9 ± 2.9 | −2.4 | −2.0 |
| T-units with ≥1 morpho-syntactic error, % | Lower better | TBL | 24 | 17.0 ± 4.6 | 23 | 12.6 ± 3.8 | 22 | 13.2 ± 4.0 | −4.4 | −3.8 |
| T-units with ≥1 morpho-syntactic error, % | Lower better | PPP | 24 | 16.8 ± 4.2 | 23 | 14.3 ± 3.9 | 22 | 14.8 ± 4.1 | −2.5 | −2.0 |
| Mean clause length | Higher better | TBL | 24 | 6.80 ± 0.90 | 23 | 8.00 ± 1.00 | 22 | 7.82 ± 0.98 | 1.2 | 1.02 |
| Mean clause length | Higher better | PPP | 24 | 6.70 ± 0.80 | 23 | 7.52 ± 0.92 | 22 | 7.31 ± 0.89 | 0.82 | 0.61 |
| Short-form Foreign Language Classroom Anxiety Scale (8–40) | Lower better | TBL | 24 | 30.0 ± 4.8 | 24 | 25.5 ± 4.3 | 23 | 26.2 ± 4.4 | −4.5 | −3.8 |
| Short-form Foreign Language Classroom Anxiety Scale (8–40) | Lower better | PPP | 24 | 30.3 ± 4.6 | 23 | 28.8 ± 4.4 | 22 | 29.2 ± 4.5 | −1.5 | −1.1 |
Table 3: Supportive speech-production and questionnaire outcomes across occasions. Words per minute, silent pauses of 0.25 s or longer per minute, percentage of T-units containing at least one morpho-syntactic error, mean clause length, and short-form Foreign Language Classroom Anxiety Scale scores at baseline (T0), immediate post-test (T1), and follow-up (T2) for the task-based learning (TBL) and Presentation-Practice-Production (PPP) conditions.
Supplementary File 1: Teaching and task materials. Six-week teaching schedule, task-based learning lesson plans, Presentation-Practice-Production lesson plans, scenario-to-target-expression mapping, oral discourse completion task prompts, and role-play scenarios and role cards used in the classroom intervention.Please click here to download this file.
Supplementary File 2: Scoring and coding materials. Oral discourse completion task and role-play scoring rubrics, rater calibration instructions, Intercultural Sensitivity Scale form and scoring rule, short-form Foreign Language Classroom Anxiety Scale form and scoring rule, transcription guidelines, T-unit and clause segmentation rules, and morpho-syntactic error taxonomy.Please click here to download this file.
Supplementary File 3: Reproducibility and analysis materials. Instructional fidelity log template, recording checklist, variable codebook, workflow summary, software and package versions, randomization documentation summary, and script inventory for dataset construction, speech-feature extraction, plotting, and model fitting.Please click here to download this file.
Supplementary File 4: De-identified raw data. Participant-level de-identified longitudinal data across baseline (T0), immediate post-test (T1), and follow-up (T2), including oral discourse completion task scores, filmed role-play scores, Intercultural Sensitivity Scale scores, short-form Foreign Language Classroom Anxiety Scale scores, and supportive speech-production measures.Please click here to download this file.