Taken from National Literacy Learning Progression:
Decodable texts are specifically written for beginning readers as they are developing their blending and segmenting skills and their knowledge of the alphabetic code. The primary purpose of decodable texts is to provide students with the opportunity to practise what has been taught during explicit, systematic phonics instruction. Decodable texts support students as they practise blending the letter-sounds they have been taught through words, in continuous meaningful text. A decodable text places gradual demands on a student’s letter-sound knowledge. The purpose is to support the development of independent phonic and fluency skills. Decodable texts are a short term support, not a long term resource for most students.