Exploring Cognitive Linguistics for Improving Phrasal Verb Learning in Vietnamese EFL Contexts

ERCT Criteria Breakdown

• Level 1 Criteria

  • C

    Class-level RCT

    • Randomisation was done at the individual student level within a single university cohort (and the paper even labels the design quasi-experimental), not at the class or school level, and the classroom-based intervention does not qualify for the tutoring exception.
    • "Eighty students were randomly divided into two groups – a control group and CL-based group." (p. 8)
    • Relevant Quotes: 1) "Eighty business-majored students from two classes were selected and divided into two groups, including a control group (n=40) and an experimental group (n=40)." (p. 1, Abstract) 2) "Participants were selected using stratified random sampling to ensure a balanced representation of genders and academic performance. They were then randomly assigned to two groups: a control group (n=40) and an experimental group (n=40) to control for any pre-existing differences between the groups." (p. 7) 3) "We employed a quasi-experimental design with pre-test, post-test, and delayed post-test measures." (p. 8) 4) "Eighty students were randomly divided into two groups – a control group and CL-based group." (p. 8) Detailed Analysis: Criterion C requires randomisation of entire classes (or schools) rather than individual students. The paper states that 80 students drawn from two classes were "randomly assigned"/"randomly divided" into a control group and an experimental group, i.e. the unit of randomisation is the individual student, not intact classes. No quote indicates that whole classes were assigned as units; on the contrary, students from two classes were pooled and split. The paper also self-describes the design as "quasi-experimental," which further undermines the claim of properly implemented randomisation. The intervention is regular whole-class instruction (two 90-minute classes per week), not one-to-one tutoring, so the tutoring exception that would permit student-level randomisation does not apply. With both groups taught in the same institution and drawn from the same cohort, contamination between conditions cannot be excluded. Criterion C is not met because randomisation was at the student level without a valid tutoring exception.
  • E

    Exam-based Assessment

    • Outcomes were measured with researcher-constructed gap-filling/multiple-choice tests built for this study, not with any widely recognised standardised exam.
    • "The study involved three tests, including pre-test, post-test and delayed post-test. All the tests were designed in the form of gap-filling of missing PVs in individual sentences." (p. 10)
    • Relevant Quotes: 1) "The study involved three tests, including pre-test, post-test and delayed post-test. All the tests were designed in the form of gap-filling of missing PVs in individual sentences." (p. 10) 2) "The pre-test (Appendix) comprises 50 multiple-choice statements. Its purpose was to evaluate the participants' comprehension of the PVs they have previously encountered. Accordingly, it was constructed based on the 81 PVs introduced in Vietnamese national high-school textbooks." (p. 10) 3) "From this list of 81 PVs, we selected 50 PVs based on two specific criteria. Firstly, we ensured that these PVs were included in The PHaVE List (Garnier & Schmitt, 2015)." (p. 10) 4) "the PVs were incorporated into novel sentences sourced from reputable academic references, namely Garnier and Schmitt (2015), Liu and Myers (2020), and Rudzka-Ostyn (2008)." (p. 10) Detailed Analysis: Criterion E requires that outcomes be measured with a standard, widely recognised standardised exam rather than an instrument created specifically for the study. Here the authors explicitly describe designing their own pre-test, post-test and delayed post-test as gap-filling / multiple-choice items which they "constructed" from textbook PV lists and corpus-based references. Although item selection drew on published frequency lists (the PHaVE List), the resulting instrument is a bespoke, researcher-assembled test with no reported external validation, norming, or use as a recognised examination (such as IELTS, TOEFL, or a national curriculum exam). No standardised test name is mentioned anywhere as the outcome measure. This is exactly the custom assessment scenario the criterion is designed to exclude because such tests can be closely aligned with the taught content, inflating apparent effects. Criterion E is not met because all outcome measures were custom tests designed by the researchers for this study.
  • T

    Term Duration

    • The interval from intervention start to the final delayed post-test is only about eight weeks (a 4-week intervention plus a 4-week delay), well short of one full academic term.
    • "The students received the specified instruction for a duration of 4 weeks, two 90-minute classes each, in September and October 2024." (p. 8)
    • Relevant Quotes: 1) "The students received the specified instruction for a duration of 4 weeks, two 90-minute classes each, in September and October 2024." (p. 8) 2) "This post-test was administered in the fourth week, after the treatment." (p. 10) 3) "The delayed post-test was conducted with the objective of evaluating the participants' long-term retention of PV knowledge. This assessment was administered four weeks after the treatment, a duration deemed suitable for students to assimilate, apply, and reinforce their PV knowledge and competencies." (p. 10) 4) "Data were collected at three different points: before the intervention (pre-test), immediately after the intervention (post-test), and one month following the intervention (delayed post-test)." (p. 10) Detailed Analysis: Criterion T requires that outcomes be measured at least one full academic term (approximately 3-4 months) after the intervention begins. Here the intervention started in September 2024 and lasted four weeks; the post-test came at the end of week four and the final delayed post-test four weeks after that. The longest interval from intervention start to the last measurement is therefore roughly eight weeks (about two months), which falls short of even the lower bound of a term (~3 months). The authors themselves acknowledge that "the initial study design constrained instructional time and follow-up period" (p. 15). No later follow-up measurement is reported. Criterion T is not met because the start-to-measurement interval of about eight weeks is shorter than one full academic term.
  • D

    Documented Control Group

    • The control group's size, baseline scores, comparability, and the traditional business-as-usual instruction it received are all explicitly documented.
    • "The Control group (henceforth, CG) received traditional PV instruction, characterized by translation, rote memorization and context-based learning without delving into the cognitive aspects of PVs." (p. 8)
    • Relevant Quotes: 1) "This study incorporated 80 undergraduate business majors from a Vietnamese university, proficient in English at the intermediate level according to the Common European Framework of Reference for Languages (CEFR). Participants were selected using stratified random sampling to ensure a balanced representation of genders and academic performance." (p. 7) 2) "The Control group (henceforth, CG) received traditional PV instruction, characterized by translation, rote memorization and context-based learning without delving into the cognitive aspects of PVs. This served as a baseline for comparing the effectiveness of the CL-based approach." (p. 8) 3) "CG (n = 40) Pre-test 45.32 12.18 ... Post-test 61.74 13.56 ... Delayed test 58.21 14.22" (Table 1, p. 11) 4) "the p-value for the pre-test indicates that there was no statistically significant difference in the baseline knowledge between the two groups (p > .05)." (p. 12) Detailed Analysis: Criterion D requires that the control group be well-documented: who they are, their baseline performance, and what treatment they received. The paper specifies the control group's size (n=40), the population it was drawn from (undergraduate business majors, intermediate CEFR level, with stratified sampling balancing gender and academic performance), its baseline pre-test performance (mean 45.32, SD 12.18, range 20-70 in Table 1), and a statistical check showing baseline equivalence with the experimental group (t = 0.42, p = 0.676). The instruction the control group received is described in concrete detail (translation lists, teacher-led explanation of PV meanings, gap-filling exercises), confirming it received the conventional programme and no element of the experimental treatment. Per-group demographic tables are not provided, but the combination of sample description, baseline scores, and treatment description satisfies the documentation requirement in line with the standard's examples. Criterion D is met because the control group's composition, baseline performance, and condition are clearly documented.

• Level 2 Criteria

  • S

    School-level RCT

    • The study randomised individual students within one university; no schools or comparable institutional units were randomised.
    • "This study incorporated 80 undergraduate business majors from a Vietnamese university... They were then randomly assigned to two groups: a control group (n=40) and an experimental group (n=40)." (p. 7)
    • Relevant Quotes: 1) "This study incorporated 80 undergraduate business majors from a Vietnamese university, proficient in English at the intermediate level according to the Common European Framework of Reference for Languages (CEFR)." (p. 7) 2) "They were then randomly assigned to two groups: a control group (n=40) and an experimental group (n=40) to control for any pre-existing differences between the groups." (p. 7) 3) "Eighty students were randomly divided into two groups – a control group and CL-based group." (p. 8) Detailed Analysis: Criterion S requires randomisation among schools or equivalent implementing institutions. This study took place within a single Vietnamese university, and the unit of randomisation was the individual student. No multiple sites, schools, or institutional units were involved or randomised, and no quote describes any school-level assignment. Criterion S is not met because randomisation occurred at the student level within a single institution, not across schools.
  • I

    Independent Conduct

    • The same authors designed the cognitive linguistics-based intervention, delivered it, collected the data, and analysed the results, with no external or independent evaluation team.
    • "The experimental group underwent a specially designed cognitive linguistics-based instructional intervention." (p. 8)
    • Relevant Quotes: 1) "The experimental group underwent a specially designed cognitive linguistics-based instructional intervention." (p. 8) 2) "In line with these considerations, this study aims to adopt a cognitive-based approach, incorporating the critical aspects outlined above." (p. 5) 3) "Conceptualization: Ton, My-Nhat Nu; Software: Tran, Nghi Validation: Ton, My-Nhat Nu Formal Analysis: Dang, Nhon; Healing of data: Tran, Nghi; Writing-Preparation of the draft original:Dang, Nhon" (p. 19) 4) "Financing: This investigation received no financing external." (p. 19) Detailed Analysis: Criterion I requires that the study be conducted independently from the designers of the intervention, or at minimum that data collection and analysis be handled by an external party. In this paper, the author team designed the CL-based instructional programme, administered the intervention and the tests, and performed the analysis, as the author contribution statement confirms (conceptualisation, validation, formal analysis and data handling all done by the three authors). There is no mention of an external evaluation agency, independent test administrators, blinded assessors, or any third-party oversight, and the study received no external financing that might imply independent monitoring. Criterion I is not met because the intervention designers themselves conducted, measured, and analysed the study with no independent oversight.
  • Y

    Year Duration

    • The total tracking period was about eight weeks, far below 75% of an academic year, and criterion T is already not met.
    • "The students received the specified instruction for a duration of 4 weeks, two 90-minute classes each, in September and October 2024." (p. 8)
    • Relevant Quotes: 1) "The students received the specified instruction for a duration of 4 weeks, two 90-minute classes each, in September and October 2024." (p. 8) 2) "This assessment was administered four weeks after the treatment, a duration deemed suitable for students to assimilate, apply, and reinforce their PV knowledge and competencies." (p. 10) 3) "For instance, the initial study design constrained instructional time and follow-up period, potentially impacting findings on longer-term retention." (p. 15) Detailed Analysis: Criterion Y requires that outcomes be measured at least 75% of a full academic year (~9-10 months) after the intervention begins. Here the entire study window, from the start of instruction in September 2024 to the delayed post-test four weeks after the 4-week treatment ended, spans roughly two months. This is nowhere near 75% of an academic year. In addition, the instructions specify that if criterion T (term duration) is not met, criterion Y cannot be met; T failed above. Criterion Y is not met because tracking lasted only about eight weeks, far short of 75% of an academic year.
  • B

    Balanced Control Group

    • Both groups received the same amount of instructional time (4 weeks, two 90-minute classes weekly) on the same phrasal verb content, with the control getting an active traditional programme, so no extra time or resources favoured the intervention group.
    • "The students received the specified instruction for a duration of 4 weeks, two 90-minute classes each, in September and October 2024." (p. 8)
    • Relevant Quotes: 1) "The students received the specified instruction for a duration of 4 weeks, two 90-minute classes each, in September and October 2024. The teaching material consists of a list of PVs in the Vietnamese national high-school textbooks (totaling 81) and 'English File - Pre-intermediate' (totaling 33) and 15 particles." (p. 8) 2) "The Control group (henceforth, CG) received traditional PV instruction, characterized by translation, rote memorization and context-based learning without delving into the cognitive aspects of PVs. This served as a baseline for comparing the effectiveness of the CL-based approach... In class, the teacher explicitly explained the meaning and usage of PVs to students." (p. 8) 3) "The CL-based group (henceforth CLG), on the other hand, received a specially designed instructional program grounded in CL principles. This program emphasized the comprehension of PVs using image-schemas and metaphorical extensions." (p. 8) Detailed Analysis: Criterion B requires that the control group receive comparable time and resources so that the effect of the specific intervention is isolated. Following the decision tree: did the intervention add extra time or budget? No. Both groups received the identical dosage - four weeks of two 90-minute classes per week - covering the same phrasal verb material drawn from the same source lists. The contrast is purely pedagogical: traditional translation/rote-memorisation/gap-fill instruction for the control versus cognitive linguistics-based instruction (image schemas, metaphorical extensions, main-verb grouping) for the experimental group. The control condition is an active, teacher-led programme rather than no treatment, and no additional materials, technology, budget, or contact hours are reported for the experimental group beyond the graphical particle diagrams and mind maps that are integral to the CL-based method itself. Because no extra educational time or resources were provided to the intervention group relative to the control, the balance requirement is satisfied. Criterion B is met because both groups received equal instructional time and comparable inputs, with only the teaching method differing.

• Level 3 Criteria

  • R

    Reproduced

    • This January 2026 study reports no independent replication of itself, and prior similar cognitive-linguistics PV studies it cites are earlier separate experiments, not replications of this trial. An internet search for citing or replicating papers found none published as of this check.
    • Relevant Quotes: 1) "A multitude of studies (Boers, 2000; Karahan, 2015; Kövecses & Szabo 1996; Lee,2012; Lin,2018; Lu & Sun,2017; Mohammed,2019; Side,1990; Spring,2018;Talebinejad & Sadri,2013; White,2012; & Yasuda, 2010) have contributed significantly to our understanding of the cognitive learning paradigm in the context of teaching English PVs." (p. 6) 2) "As such, this study seeks to bridge the gap by exploring the potential of cognitive-based methods in teaching English PVs within the Vietnamese context, aiming to assist Vietnamese EFL learners in comprehending and retaining the nuances of PVs while extrapolating metaphorical knowledge to new instances." (p. 3) 3) "Generalizing implications to other contexts was limited given the singular Vietnamese sample." (p. 15) Detailed Analysis: Criterion R requires that this specific study be independently replicated by a different research team in a different context and published in a peer-reviewed journal. The paper was published on 13 January 2026, only about six months before this check, and internet searches (Crossref metadata and Google Scholar) found no citing works, no replication studies, and no follow-up papers referencing this specific trial. The many earlier cognitive-linguistics phrasal verb experiments cited (Boers 2000, White 2012, Spring 2018, Mohammed 2019, etc.) are prior independent studies of the general approach in other populations; they predate this study and are not replications of its specific design, sample, or findings. The authors themselves frame their work as addressing an under-researched Vietnamese context and note that generalisation is limited by the singular sample. Criterion R is not met because no independent, peer-reviewed replication of this specific study exists, and none was found via internet search.
  • A

    All-subject Exams

    • Criterion E failed (custom tests), and only English phrasal verb knowledge was assessed, with no other core subjects measured.
    • "The study involved three tests, including pre-test, post-test and delayed post-test. All the tests were designed in the form of gap-filling of missing PVs in individual sentences." (p. 10)
    • Relevant Quotes: 1) "The study involved three tests, including pre-test, post-test and delayed post-test. All the tests were designed in the form of gap-filling of missing PVs in individual sentences." (p. 10) 2) "The post-test aimed to evaluate both the participants' understanding of not only the PVs they had previously learnt but also some novel PVs." (p. 10) Detailed Analysis: Criterion A requires standardised exam-based assessment of all main subjects taught at the relevant educational level, with criterion E as a prerequisite. Criterion E is not met here because the outcome measures are custom researcher-designed tests, so criterion A automatically fails. Moreover, the study measured only one narrow domain - knowledge of English phrasal verbs - and did not assess any other subjects in the students' business degree programme or even broader English proficiency. No justification is given that would satisfy the specialised-intervention exception in the sense of covering all directly related subjects with standardised exams. Criterion A is not met because criterion E failed and only a single narrow outcome domain was assessed.
  • G

    Graduation Tracking

    • Measurement stopped four weeks after the 4-week intervention, with no tracking of participants to graduation and criterion Y already unmet. No follow-up publication tracking this cohort was found via internet search.
    • "This assessment was administered four weeks after the treatment, a duration deemed suitable for students to assimilate, apply, and reinforce their PV knowledge and competencies." (p. 10)
    • Relevant Quotes: 1) "This assessment was administered four weeks after the treatment, a duration deemed suitable for students to assimilate, apply, and reinforce their PV knowledge and competencies." (p. 10) 2) "For instance, the initial study design constrained instructional time and follow-up period, potentially impacting findings on longer-term retention." (p. 15) 3) "Addressing gaps through future comparative and longitudinal investigations incorporating diverse methodologies can further advance understanding of cognitive linguistics' role in PV pedagogy." (p. 15) Detailed Analysis: Criterion G requires following participants until graduation from their educational stage. The final data point in this study is a delayed post-test four weeks after the end of a four-week intervention; the undergraduate participants were not tracked to the completion of their degree programme. The authors acknowledge the constrained follow-up period as a limitation and call for future longitudinal investigations, confirming that no graduation tracking occurred. An internet search for later publications by the same three authors tracking this cohort toward graduation returned no results. Additionally, the instructions specify that if criterion Y is not met, criterion G cannot be met; Y failed above. Criterion G is not met because tracking ended four weeks after the intervention, far short of participants' graduation, and no follow-up tracking papers were found.
  • P

    Pre-Registered

    • The paper contains no mention of any pre-registered protocol, trial registry, or registration date.
    • Relevant Quotes: 1) "All research activities were conducted in compliance with ethical standards. Participants were informed about the purpose of the study and the nature of the intervention. Informed consent was obtained... The study received ethical approval from the university's review board." (p. 11) Detailed Analysis: Criterion P requires that the full study protocol, including hypotheses, methods, and planned analyses, be registered on a public registry before data collection began. The paper describes ethical approval and informed consent but nowhere mentions pre-registration, a registry platform (e.g., OSF, ClinicalTrials.gov, AEA registry), a registration ID, or a registration date. Ethics-board approval is not a substitute for public pre-registration of hypotheses and analysis plans. Criterion P is not met because no pre-registration of the study protocol is reported anywhere in the paper.