I would appreciate it if you are able to tell me whether you believe that 'most' teachers, at the moment, in the West, are not 'expert' teachers, but are rather either 'inexperienced' or 'experienced.'

My best estimate (from our work, from NBPTS [National Boards for Professional Teaching Standards] in the US) we have about 5-10% Lead, 10-15% HA – here in Oz [Australia] I have sufficient data to say 60-70% are proficient – in that their students make at least a year’s growth for a year’s input – pretty impressive – but we are going backwards on this percent which is why we are slipping in TIMSS [Trends in International Mathematics and Science Study], PISA [Program for International Student Assessment], etc.” (John Hattie, personal communication, March 13, 2018).