Are you thinking about purchasing an intervention for some aspect of literacy?
When considering purchasing a commercial intervention it can be useful to research the intervention first. Brook’s What Works for Literacy Difficulties, contains a lot of useful information around the effectiveness of different interventions based on research trials. It will also indicate the purpose of the intervention, the length of time that the intervention should run for and whether it is a one-to-one intervention or designed for use in small groups or usable within a class situation.
You can access this book, using the hyperlink below.
Brook’s What Works for Literacy Difficulties 6th Edition 2020

Thank you – the linked document is an extremely useful, comprehensive reference.