Education Endowment Foundation:Butterfly Phonics

Butterfly Phonics

Real Action
Implementation cost 
Evidence strengthNot given for this trial
Impact (months)
Independent Evaluator
Durham University
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Testing the impact of an out-of-school-hours phonics programme.
Schools: 5 Grant: £457,980
Key Stage: 1 Duration: 1 year(s) 11 month(s) Type of Trial: Efficacy Trial
Completed January 2014

Butterfly Phonics aims to improve the reading of struggling pupils through phonics instruction and a formal teaching style where pupils sit at desks in rows facing the teacher. The teacher directs questions to the pupils throughout the lesson in order to check their understanding. It is based on a course book created by Irina Tyk, and was delivered in this evaluation by Real Action, a charity based in London.

Real Action staff recruited and trained practitioners to deliver the intervention. These practitioners worked with trained teaching assistants to teach classes of six to eight pupils, although some groups were larger. Pupils were eligible for participation in the trial if they did not reach level 4 in their Key Stage 2 SATs or their reading skills were at least a year behind their chronological age. In most schools, lessons were taught over a period of ten to twelve weeks, typically with two one-hour lessons each week. One school delivered the intervention over just four weeks, and the implications of this variation are discussed in the main body of the report.

The evaluation was set up as a randomised controlled trial, which compared the progress of pupils who received Butterfly Phonics to a business-as-usual” control group. It did not test the delivery model at scale, and should therefore be considered an efficacy trial. The study was funded by the Education Endowment Foundation as one of 23 projects focused on literacy catch-up at the primary-secondary transition. It is one of seven literacy catch-up projects with a focus on phonics.

  1. This evaluation provided evidence of promise; there was a positive, statistically significant effect on the primary outcome measure of reading comprehension. However, this effect size was lower than the minimum detectable effect size of the trial, so we cannot confidently conclude that the effect was due to the intervention and did not occur by chance.
  2. The secondary outcome measures indicated positive impacts on children’s literacy skills, but these were not statistically significant.
  3. This intervention is recommended to take place during the school day, when it is easier to secure sustained co-operation and support from school staff. Where that support was present, the intervention was able to progress more satisfactorily than in schools where it was lacking.
  4. Schools should ensure that people delivering the intervention receive training in the Butterfly method so that it is implemented as intended.
  5. Further research could investigate the intervention’s impact on early readers. Its emphasis on larger word units and comprehension skills might enable a more rapid progression in early reading than a pure phonics course.

The evaluation found that, on average, the reading comprehension skills of pupils who received the intervention improved at a faster rate than those in the control group. This improvement is equivalent to the pupils who received the intervention making an additional five months’ progress over the course of the school year. This estimate is statistically significant, but the observed effect size is lower than the minimum detectable effect size that was specified at the beginning of the study. This means that, although this evaluation provides evidence of promise, we are unable to confidently conclude that the observed effect is real and did not occur by chance.

The evaluation also considered the impact of the intervention on two secondary outcome measures of literacy skills, but did not find statistically significant impacts.

Butterfly phonics effect table
Impact of the intervention on two secondary outcome measures of literacy skills.