Butterfly is a synthetic phonics based reading programme for struggling readers. The programme, which follows the structure laid out by Irina Tyk’s ‘butterfly grammar book’, begins with alphabetic principles and progresses through irregular orthography, aiming to produce proficiency in reading and spelling. It is taught mainly in a didactic manner, with students facing the teacher in rows and interacting predominantly with the teacher rather than their peers.
Butterfly can be delivered in several ways: through a Butterfly Saturday Reading School which runs for 2 hours each Saturday; through a Butterfly Summer School which runs for 2 hours each weekday over the summer break; or based in a primary or secondary school and running during normal school hours.
Butterfly Phonics was evaluated by the Education Endowment Foundation in 2015. The evaluation provided some evidence of promise but the intervention group received extra English time and the post-tests were disrupted meaning a reliable estimate of the impact of the intervention could not be produced.
The Education Endowment Foundation evaluation found evidence of promise with an effect size of 0.43 for secondary reading but the study was not accepted.