Cognitive acceleration: Effects of a one-year Let’s Think in English intervention in an International School


Our purpose was to explore the effects of Let’s Think in English (LTE) on the quality of critical and creative thinking in the grade 5 and 6 classes in an International school in Zürich. We also wanted to explore the cognitive development of the students and the further development and transfer of these skills and dispositions into middle school learning and beyond, thus strengthening the ties between the primary and secondary schools.

LTE is being developed at a not for profit educational consortium with deep roots in King’s College London. The non-profit status makes it a good fit for our school’s inclusive, non-profit model, and connections to a research university mean that there is a body of evidence supporting the efficacy of the approach.


International schools often have students and teachers with a very diverse language, schooling and emotional history, often marked by a transient lifestyle and frequent changes of curriculum, language and instructional styles. Also the International Baccalaureate makes great claims that it is a programme that aims at life long learning and enduring understandings are a major goal of the programmes. We wanted to explore evidenced-based interventions that could substantiate these claims.

There were six teachers directly involved as recipients of the LTE training and lesson delivery. Two teachers were primary class teachers, two were lower secondary teachers of English. Another was responsible for English as an Additional Language (EAL) support in the primary school and the author a secondary Science, Biology and Theory of Knowledge teacher. The initial plan was supported by the school administration for one year even though we stressed that LTE is a two year intervention.

Research question(s):

  • What distribution of cognitive development is observable in students making the primary to secondary transition at a Zürich International School?  These would be measured using pre and post testing using the Piagetian Scientific Reasoning Tasks developed by Shayer and Adey (1981)
  • What positive effects will a structured programme of thinking lessons through this transition have on cognitive development? As well as the quantitative Piagetian data, we used the ACER tests that the students normally take every October in Mathematical Literacy, Reading, Narrative and Expository writing. We also wanted to develop qualitative observational and semi structured dyadic discussion observations.
  • How will the training associated with delivering this programme develop the pedagogy and practice of the teachers involved? In particular, their expertise in eliciting, assessing and mediating student thinking. We used a pre-intervention self assessment of how each teacher rated themselves as a Teacher of Thinking, and then used a post-intervention self-rating at the end of the year.

Results and discussion


  1. The Growth in Piagetian mean reasoning levels shown by the red line in the graph represented a 0.8  effect size (Cohen’s d; n = 59; p <0.01, two-tailed t-test) for treatment group compared with the mean change blue line shown by a sample of UK students. This sample of  n = 11,000 was used for control measures in many cognitive acceleration studies.

2) We also used Australian Council for Educational Research (ACER) tests. These use the same scale and psychometric model as the PISA tests. Our students took Mathematical Literacy, Reading, Narrative writing and Expository writing. We used these tests to show the persistence of the cognitive gains and how they would have  transfer effects to other subjects or domains more than a year after the start of the intervention. Our students took these ACER test in October 2016 and again in October 2017. For a small sample (n = 35, due to students leaving or arriving after the pre and post ACER tests) we got these effect sizes (Cohen’s d) compared to a very stringent control of the top 14 International Baccalaureate schools (n = 865) performance on the same tests as reported by Tan and Bibby (2011).

Mathematical Literacy (0.27) , Reading (0.3) , Narrative writing (0.12)  and Expository writing (0.42).

The Expository writing had a p value <0.01 and Mathematical literacy had a p value of <0.10 (two-tailed t-test). Interestingly, the growth shown by the lowest quartile of our research sample showed even higher effects on the four ACER tests.

Mathematical Literacy (0.61) , Reading (0.42) , Narrative writing (0.46)  and Expository writing (0.67).

This effect on the least cognitively developed students has been consistently measured in previous cognitive acceleration research.

Note: that these are effect size gains compared to a group that has also grown in the expected trajectory for these leading schools. So the 0.4 Hattie hinge point is not really relevant here as he assumes 0.4 is the result of natural maturation, we have accounted for that in our calculations. Our  results compare the  growth between the two groups in the 4 domains covered by the ACER results.

These promising results demonstrate that our intervention in English led to success across cognitive domains like Mathematical Literacy as well as English competences. This research needs further follow up and replication with a wider sample size. This is in planning for the coming years in other International schools.


Illustrative teacher comments:

“I learned new ways to develop student thinking within my classroom. I had of course always valued student thinking and loved Visible Thinking with Ron Ritchhart. However LTE pushed me to develop and think about what ‘deep’ thinking actually is and how to encourage this. I have actually learned how to structure the development of students’ cognitive skills. I liked the structure of the lessons which now means I am able  to begin planning my own lessons more effectively with the principles in mind. I feel I’m on the way to really developing a more sophisticated culture of thinking within my classroom.”

“Having a greater awareness of the way students know and think has changed my understanding of “prior knowledge”.  I have often heard and used the term prior knowledge as important to know what to teach students. I now understand better how important it is to understand not just what students know, but how they know it.  It is also important to know their readiness for new understanding and how to accelerate that readiness. These ideas have changed how I teach in many areas but most significantly in teaching reading”

Illustrative student comments:

“My favourite lesson was voices in the park because we reviewed it many times so each time we saw it again we would look at the story from different perspectives. We had a lot of thinking which gave us many ideas to figure out how the characters feel.”

“I think it has helped me in other subjects in school because it has taught me to think before you randomly shout out an answer.”

“I thought there really was nothing it taught us other than thinking a little deeper.”

Concept mapping

Novak and Gowin (1984) developed a point scoring system to capture the level of cognitive grasp of a domain of understanding. McMurray (2012) at the University of Waterloo further developed this into a rubric to rate the complexity of concept maps to cognitive structure.

Grade 5 Students produced concept maps at the end of an inquiry unit into energy. Our preliminary analysis of these show evidence of an increased complexity of structure, clearer propositional linking and an overall increase in displaying conceptual hierarchy.


As we did not use a control group design we could not even claim quasi experimental causality between the LTE intervention and the cognitive and academic gains. However our use of residual gains compared to a large existing dataset as a control allowed us some robust correlational claims to statistically significant effects on student cognition.

The qualitative data paints a consistent picture of increased teacher awareness and agency. The effect on teacher perception of their role in leading discussions and applying their learning to new situations  was one of the most tangible outcomes.


Identification of Key Outcomes & Project Impact

  1. Increases in student thinking capabilities in particular the maturing of concrete operational thought and an earlier development of formal operational thinking.
  2. These cognitive developments should be associated with an  increase in understanding, application and communication of subsequent learning.
  3. Increases in teacher understanding and skill in application of the principles of developing and assessing  student thinking.
  4. Increasing teacher awareness about classroom practice and learning by using a diversity of ways of knowing.
  5. Strengthened ties between the primary and secondary teachers leading to a smoother transition for the students.

One of the outstanding experience and lessons to learn was that this action research was highly disruptive to the top down strategic model of the school administration and possibly competed with their external expert driven metacognition project. So any future action research has to weigh up the socio-political landscape. This is a major reason why the outcomes have not been systematically maintained.


McMurray, J  (2012) Rubric for assessing concept maps. Centre for Teaching Excellence. Available at: [Accessed April 9, 2016].

Novak, J. D., & D. B. Gowin. (1984). Learning How to Learn. New York and Cambridge, UK: Cambridge University Press.

Shayer, M and Adey,P (1981) Towards a science of science teaching, Heinemann, London

Shayer,M and Adey,P (1994) Really Raising Standards: Cognitive intervention and academic achievement, Routledge, London

Tan, Ling and Bibby, Yan, “Performance Comparison between IB School Students and Non-IB School Students on the International Schools’ Assessment (ISA) and on the Social and Emotional Wellbeing Questionnaire” (2011)

Image: Pixabay

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