Examining the effectiveness of targeted morphological instructions on reading outcomes: a randomized controlled trial involving Chinese EFL learners

ERCT Criteria Breakdown

• Level 1 Criteria

  • C

    Class-level RCT

    • Students were randomised individually within each class (within-class randomisation), not by whole classes or schools, and the intervention was whole-class instruction, not one-to-one tutoring, so no exception applies.
    • "Within-class randomisation was conducted to control for overall teacher or classroom effects on outcomes." (p. 74-75)
    • Relevant Quotes: 1) "Three classes and their three English teachers were recruited from a secondary school located in mainland China. Within-class randomisation was conducted to control for overall teacher or classroom effects on outcomes." (p. 74-75) 2) "More specifically, the students within each class were grouped into blocks based on their pretest reading scores (i.e. word reading and reading comprehension). Then, the students within each block were randomly assigned to one of the three research conditions, forming three groups (i.e., MDe, MAn or the affix knowledge group)." (p. 75) 3) "A total of 156 Grade-8 students were randomly assigned to one of three groups: morphological analysis group (experimental group 1), morphological decoding group (experimental group 2) or affix knowledge group (active control group)." (p. 69, Abstract) Detailed Analysis: Criterion C requires randomisation at the class level or stronger (school level). The paper explicitly states that randomisation was conducted within classes: individual students inside each of the three recruited classes were blocked on pretest reading scores and then randomly assigned to one of the three conditions. This is student-level randomisation within existing classes, which is exactly the design the criterion warns against because of contamination risk (students in different conditions share the same school environment, and the three teachers each taught one condition within the same school). The exception for one-to-one tutoring or personal teaching does not apply: the interventions were delivered to groups in a whole-class manner ("it is feasible for school teachers to implement morphological instruction in a whole-class manner", p. 83), not as individual tutoring. Criterion C is not met because randomisation was performed at the individual student level within classes, not at the class or school level, and no tutoring exception applies.
  • E

    Exam-based Assessment

    • The primary and most outcome measures were researcher-developed or research-specific instruments (affix knowledge test, morphological awareness tasks, Tong et al. reading comprehension task), not widely recognised standardised exams, with only part of the word reading composite (WRAT-4) being standardised.
    • "It was evaluated with a researcher-developed written test that included 10 items on prefixes and 6 items on suffixes." (p. 76)
    • Relevant Quotes: 1) "Affix knowledge is regarded as a program-related measure as it was explicitly taught across all conditions. It was evaluated with a researcher-developed written test that included 10 items on prefixes and 6 items on suffixes." (p. 76) 2) "Morphological structure awareness is a near-transfer measure, as it is the primary outcome of the intervention. Morphological structure awareness was assessed with three tasks... The three tasks included the 20-item word analogy measure (Kirby et al., 2012), the 28-item Test of Morphological Structure (Carlisle, 2000) and the 11-item morphological compounding test (Tong et al., 2018)." (p. 77) 3) "Word reading was measured using the Wide Range Achievement Test-4 (50 items; Wilkinson & Robertson, 2016) and another word reading test (60 items; Tong & McBride-Chang, 2010)." (p. 78) 4) "Reading comprehension was assessed with a task designed by Tong et al. (2017). This task includes two reading passages, each accompanied by 10 to 13 multiple-choice questions and 3 open-ended questions." (p. 78) Detailed Analysis: Criterion E requires that outcomes be measured with standard, widely recognised standardised exams rather than instruments created or assembled for the study. Here the stated primary outcome (morphological structure awareness) was measured with research instruments drawn from prior studies, not standardised exams. The program-related affix knowledge measure was explicitly "researcher-developed". Reading comprehension was measured with a task "designed by Tong et al. (2017)", a research instrument, not a national or state standardised exam. Only word reading partially used a recognised standardised test (WRAT-4), but it was combined into a composite with another research word reading test (Tong & McBride-Chang, 2010), so even this outcome is not a pure standardised exam score. Taken as a whole, the assessment battery is dominated by researcher-developed and research-specific measures aligned with the intervention content, which is precisely the bias the criterion is designed to prevent. Criterion E is not met because the outcomes, including the primary outcome and reading comprehension, were assessed with researcher-developed or research-specific tasks rather than widely recognised standardised exams.
  • T

    Term Duration

    • The intervention lasted only five weeks and outcomes were measured immediately after it ended, far short of one academic term of tracking from intervention start.
    • "The three programs were delivered twice per week (50 min/session), lasting for 5 weeks." (p. 78)
    • Relevant Quotes: 1) "The three programs were delivered twice per week (50 min/session), lasting for 5 weeks." (p. 78) 2) "All assessments were conducted before and immediately after the intervention." (p. 76) 3) "Each intervention consisted of two 50 min sessions per week over a five-week period." (p. 69, Abstract) 4) "Finally, our interventions were delivered over a relatively short period of 5 weeks with 10 sessions, totalling slightly more than 8 h of total contact time; additionally, no delayed posttest was included to assess whether the beneficial effects remained over time." (p. 84-85) Detailed Analysis: Criterion T requires that outcomes be measured at least one full academic term (about 3-4 months) after the intervention begins. The intervention here ran for only five weeks (10 sessions of 50 minutes), and the posttest was administered "immediately after the intervention". The interval from intervention start to outcome measurement is therefore about five weeks, well under a term. The authors themselves acknowledge the short duration and the absence of any delayed posttest as limitations. There is no term-long follow-up tracking of any kind. Criterion T is not met because outcomes were measured only about five weeks after intervention start, far less than one full academic term.
  • D

    Documented Control Group

    • The active control (affix knowledge) group is documented in detail, including its instructional condition, baseline equivalence checks, and pretest/posttest descriptive statistics in Table 1.
    • "The program in this active control condition aims to teach students affix knowledge, including the sound, form and meaning of the affixes." (p. 79)
    • Relevant Quotes: 1) "Affix knowledge condition. The program in this active control condition aims to teach students affix knowledge, including the sound, form and meaning of the affixes. Compared with business-as-usual control, we used a more stringent control, where students learn the affix knowledge, but the focus is not on morphological decoding, analysis, or other strategies throughout the program." (p. 79) 2) "Our participants were 156 Grade 8 Chinese students (average age: 13.74 years; SD: 0.37) who attended a large school and learned English as a foreign language. Students began learning English in Grade 3." (p. 76) 3) "One-way ANOVA revealed no statistically significant differences between groups on these measures at pretest (ps > 0.10), suggesting effective overall matching by condition." (p. 80) 4) "Table 1 presents the descriptive statistics for all observed variables for each group at both the pretest and posttest, including means, standard deviations, and reliability measures." (p. 80) Detailed Analysis: Criterion D requires clear documentation of the control group: who they are, their baseline performance, and what treatment they received. The paper describes the active control condition in detail, including a full step-by-step program overview (Appendix C) specifying exactly what the control students received (affix knowledge instruction without morphological strategy training). Participant demographics are reported for the sample (Grade 8, mean age 13.74, EFL background), randomisation was blocked on pretest reading scores, baseline equivalence across the three groups was tested and confirmed (ps > 0.10), and Table 1 reports pretest and posttest means, standard deviations, and reliabilities separately for the control group on every outcome. This provides adequate documentation of the control group's composition, baseline performance and treatment. Criterion D is met because the control group's condition, baseline performance and characteristics are clearly and thoroughly documented.

• Level 2 Criteria

  • S

    School-level RCT

    • The study took place in a single school with students randomised within classes; no schools were randomised.
    • "Three classes and their three English teachers were recruited from a secondary school located in mainland China." (p. 74)
    • Relevant Quotes: 1) "Three classes and their three English teachers were recruited from a secondary school located in mainland China. Within-class randomisation was conducted to control for overall teacher or classroom effects on outcomes." (p. 74-75) 2) "Our participants were 156 Grade 8 Chinese students (average age: 13.74 years; SD: 0.37) who attended a large school and learned English as a foreign language." (p. 76) Detailed Analysis: Criterion S requires randomisation at the school level, i.e., multiple schools (or equivalent implementation units) randomly assigned to conditions. This study involved a single secondary school, from which three classes were recruited, with individual students randomised within each class. No schools or comparable institutional units were randomised. Because randomisation occurred at the student level within one school, the school-level requirement is clearly not satisfied. Criterion S is not met because the trial was conducted in one school with within-class student-level randomisation, not school-level randomisation.
  • I

    Independent Conduct

    • The authors designed the interventions and measures and conducted the evaluation themselves; teacher blinding is noted but there is no independent third-party evaluation team.
    • "In the present study, we designed theory-driven morphological instruction with precise targeted components (i.e., morphological analysis, morphological decoding, and affix knowledge) and adopted a randomised controlled trial design for evaluation." (p. 71)
    • Relevant Quotes: 1) "In the present study, we designed theory-driven morphological instruction with precise targeted components (i.e., morphological analysis, morphological decoding, and affix knowledge) and adopted a randomised controlled trial design for evaluation." (p. 71) 2) "(2) direct teaching of the affixes of the day (i.e., sound, form and meaning of affixes) through researcher-designed animated videos" (p. 78) 3) "The intervention teachers were school English teachers who had a similar number of years of experience teaching regular classes and were trained to deliver the programs... All the teachers were blinded to the research aims and hypotheses." (p. 78) 4) "Assessments were conducted at the participants' school by trained English teachers." (p. 76) Detailed Analysis: Criterion I requires that the study be conducted independently from the designers of the intervention, for example by an external evaluation team. Here the research team explicitly designed the three morphological programs (including researcher-designed videos and a researcher-developed affix knowledge test) and also designed, ran and analysed the trial themselves. Delivery was by school teachers blinded to the research aims, and assessments were administered by trained English teachers, which mitigates some implementation bias, but there is no statement of an external, independent evaluation agency or third-party oversight of data collection, analysis or conclusions. The same team that developed the interventions carried out the evaluation. Criterion I is not met because the intervention designers themselves conducted and analysed the trial without documented independent third-party evaluation.
  • Y

    Year Duration

    • The study tracked outcomes for only about five weeks, far below 75% of an academic year, and criterion T is also not met.
    • "The three programs were delivered twice per week (50 min/session), lasting for 5 weeks." (p. 78)
    • Relevant Quotes: 1) "The three programs were delivered twice per week (50 min/session), lasting for 5 weeks." (p. 78) 2) "All assessments were conducted before and immediately after the intervention." (p. 76) 3) "Finally, our interventions were delivered over a relatively short period of 5 weeks with 10 sessions, totalling slightly more than 8 h of total contact time; additionally, no delayed posttest was included to assess whether the beneficial effects remained over time." (p. 84-85) Detailed Analysis: Criterion Y requires outcome measurement at least 75% of an academic year (roughly 9-10 months) after intervention start. The intervention and measurement window here spanned only about five weeks, with no delayed posttest or longer follow-up. Additionally, per the ranking instructions, criterion Y cannot be met when criterion T (term duration) is not met, and T is not met for this paper. Criterion Y is not met because the interval from intervention start to measurement was about five weeks, nowhere near 75% of an academic year.
  • B

    Balanced Control Group

    • An active control group received the same dosage (two 50-min sessions per week for 5 weeks), the same affix content, teacher training, videos, reading passages and games, differing only in the targeted strategy instruction being tested.
    • "Compared with business-as-usual control, we used a more stringent control, where students learn the affix knowledge, but the focus is not on morphological decoding, analysis, or other strategies throughout the program." (p. 79)
    • Relevant Quotes: 1) "The three programs were delivered twice per week (50 min/session), lasting for 5 weeks. The interventions took place during a specific time period allocated by the school, when no official classes were held." (p. 78) 2) "Compared with business-as-usual control, we used a more stringent control, where students learn the affix knowledge, but the focus is not on morphological decoding, analysis, or other strategies throughout the program." (p. 79) 3) "Across all the conditions, the students were given explicit instruction on affix knowledge. More specifically, the students were asked to watch a short animation-based video at the beginning of each lesson... The affixes and their respective word stimuli taught across conditions are identical." (p. 79) 4) "(4) having students read a passage and complete corresponding exercises, as conducted in the MAn and MDe programs" (p. 79) 5) "The intervention teachers were school English teachers who had a similar number of years of experience teaching regular classes and were trained to deliver the programs." (p. 78) Detailed Analysis: Applying the criterion B decision tree: the first check is whether the intervention (MDe/MAn) conditions receive extra time or budget relative to the control. Here all three conditions, including the affix-knowledge control, received the identical dosage of two 50-min sessions per week for five weeks, delivered by teachers with similar experience who received the same training, using the same affixes and word stimuli, the same animation-based direct-teaching videos, and comparable reading-comprehension passages, exercises and mastery games. Because no extra time, budget or materials were allocated to the experimental conditions relative to the control, the "no extra resources present" branch of the decision tree applies and the criterion is satisfied on that basis alone; the only difference between conditions is the targeted strategy content itself (word mapping/decoding-fluency practice in MDe, analysis and counterexample discussion in MAn, versus worksheet practice in the control), which is exactly the treatment contrast being tested rather than an imbalance in resources. Criterion B is met because the active control group received equivalent instructional time, materials and teacher support, with only the tested strategy component differing between conditions.

• Level 3 Criteria

  • R

    Reproduced

    • The paper is explicitly presented as the first study of its kind, and an internet search of its citation record found no independent replication by a different research team.
    • "This research presents the first empirical evidence regarding the relative effectiveness of morphological skills (i.e., morphological analysis and morphological decoding) and affix knowledge in developing English reading-related skills" (p. 69)
    • Relevant Quotes: 1) "This research presents the first empirical evidence regarding the relative effectiveness of morphological skills (i.e., morphological analysis and morphological decoding) and affix knowledge in developing English reading-related skills, word reading and reading comprehension among Chinese EFL students." (p. 69) 2) "To the best of our knowledge, this is the first study to contrast the effects of morphological skills (i.e., MDe, MAn) and affix knowledge on reading outcomes among Chinese EFL learners." (p. 74) 3) "Future studies may replicate this research using a longer intervention period and administering a delayed posttest." (p. 85) Detailed Analysis: Criterion R requires that the study be independently replicated by a different research team in a different context, published in a peer-reviewed journal. The authors repeatedly describe this trial as the first of its kind, and they call for future replication, indicating none exists yet. The paper was published online in January 2025; related morphological intervention studies cited (e.g., Savage et al., 2024, which shares an author; Gellert et al., 2021) are prior studies of different designs and populations, not replications of this specific three-arm contrast among Chinese EFL Grade 8 learners. An internet search of the paper's citation record (Semantic Scholar/OpenAlex, corpus ID 275935059) was conducted to check for any independent replication published since. Four citing works were found: Tian and Ngui (2026), a pilot study of morphological instruction among Malaysian lower-secondary limited-English-proficient learners; Gai and Jiang (2026), on phonics instruction for Chinese-speaking adults; Sijali, Poudel and Dahal (2026), a systematic review of RCTs in English language education; and Punkhoom et al. (2025), on TikTok-based vocabulary learning for Thai EFL students. None of these studies replicate the specific three-arm MDe/MAn/affix-knowledge contrast among Chinese Grade 8 EFL learners used in this trial, and none share authors with the original study. No independent replication of this particular study was identified. Criterion R is not met because the study is presented as a first-of-its-kind trial and no independent replication has been published.
  • A

    All-subject Exams

    • Only English reading-related outcomes were measured, no other core subjects were assessed, and prerequisite criterion E is not met.
    • "we administered three types of measures before and after receiving the intervention: program-related measures (i.e., affix knowledge), near-transfer measures (i.e., morphological structure awareness), and far-transfer measures (i.e., word reading and reading comprehension)." (p. 76)
    • Relevant Quotes: 1) "To evaluate students' performance, we administered three types of measures before and after receiving the intervention: program-related measures (i.e., affix knowledge), near-transfer measures (i.e., morphological structure awareness), and far-transfer measures (i.e., word reading and reading comprehension)." (p. 76) 2) "The present randomised controlled trial aims to investigate the effects of MDe, MAn, and affix knowledge on reading outcomes, including word reading and reading comprehension." (p. 74) Detailed Analysis: Criterion A requires assessment of all main school subjects with standardised exams to detect potential negative spillover effects on non-target subjects. This study measured only English reading-related outcomes (affix knowledge, morphological awareness, word reading, reading comprehension). No other core subjects for Grade 8 in mainland China (e.g., Chinese, mathematics, science) were assessed, and no justification for a specialised exception is given (Grade 8 general secondary education is not a specialised vocational context). In addition, per the instructions, criterion A cannot be met when criterion E is not met, and E is not met here because the measures were largely researcher-developed rather than standardised exams. Criterion A is not met because only English reading outcomes were assessed, other main subjects were not measured, and the prerequisite criterion E fails.
  • G

    Graduation Tracking

    • Measurement ended immediately after the 5-week intervention with no delayed posttest or tracking toward graduation, an internet search found no graduation-tracking follow-up by the same authors, and prerequisite criterion Y is not met.
    • "no delayed posttest was included to assess whether the beneficial effects remained over time" (p. 84-85)
    • Relevant Quotes: 1) "All assessments were conducted before and immediately after the intervention." (p. 76) 2) "Finally, our interventions were delivered over a relatively short period of 5 weeks with 10 sessions, totalling slightly more than 8 h of total contact time; additionally, no delayed posttest was included to assess whether the beneficial effects remained over time." (p. 84-85) Detailed Analysis: Criterion G requires participants to be tracked until graduation from their educational stage. Here, outcome measurement stopped immediately after a 5-week intervention with Grade 8 students; the authors explicitly state that no delayed posttest was included and recommend future studies add longer follow-up. An internet search (Semantic Scholar/OpenAlex citation records, corpus ID 275935059) was conducted for subsequent papers by Yeung, Qiao, Law or Savage that might track this same Grade-8 cohort toward graduation. The paper's four known citing works (Tian & Ngui, 2026; Gai & Jiang, 2026; Sijali, Poudel & Dahal, 2026; Punkhoom et al., 2025) are all by unrelated author teams on unrelated populations, and none report longer-term or graduation-tracking follow-up of this cohort. No graduation-tracking follow-up publication by the original authors was found. In addition, per the instructions, criterion G cannot be met when criterion Y is not met, and Y is not met for this paper. Criterion G is not met because tracking ended immediately after the short intervention with no follow-up to graduation, and no subsequent graduation-tracking publication by the same authors could be located.
  • P

    Pre-Registered

    • The paper contains no mention of any trial registry, pre-registration ID, or pre-registered protocol, and an internet search of trial registries found no matching registration.
    • Relevant Quotes: 1) "The current study adopted a randomised controlled trial design, following the CONSORT standards (see Fig. 1)." (p. 74) 2) "A randomisation schedule was generated by using a Clinical Trial Randomisation Tool from the National Cancer Institute (https://ctrandomization.cancer.gov/tool/)." (p. 76) Detailed Analysis: Criterion P requires that the full study protocol be pre-registered in a registry before data collection, with the registration identifiable and dated. Although the authors report following CONSORT standards and using a formal randomisation tool, nowhere in the paper is there a registry name, registration number, registration date, or any statement that the hypotheses, methods and analysis plan were pre-registered before data collection. Following CONSORT reporting guidelines is not the same as pre-registering the protocol. An internet search of trial registries (ClinicalTrials.gov and the OSF Registries) for a pre-registration matching this study (morphological decoding/analysis/affix knowledge instruction among Grade 8 Chinese EFL learners by Yeung, Qiao, Law or Savage) did not locate any matching registration, consistent with the absence of any registry reference in the paper itself. Criterion P is not met because the paper provides no evidence of pre-registration of the study protocol, and no matching registry entry could be located via internet search.