the most effective schools improve teaching practices by encouraging their teachers to discuss their professional learning plans with each other so that they can support each other s growth cole professional learning is most effective at sustaining improvement to teachers competence when it is collaborative and embedded in their work including activities such as classroom observations group discussions and collective preparation of instructional material coaching and mentoring schleicher however it was reported to the oecd review team during interviews that the pedagogical circles tend to be formal and are mainly used to transmit information