Seriously Robert, I do buy into the whole improvement thing, but if you want me to get better as a teacher, why don't you just observe me, then tell me something that I could improve? I'd be up for it. Why do I have to spend hours attending PLC meetings, observing, coaching, being observed and being coached? It just seems like a huge waste of time, when we all know that we are desperately time-poor as teachers.
I would respond as follows:
There are many reasons why I think it is better to be in a PLC than to follow your suggestion, even though PLCs take more time.
1. Being told to make a change to one's practice rarely leads to a permanent change in practice. I wish this were not true, but all the research I have seen indicates that it is. And not just for other people - it is true for you and me!
2. PLCs improve the capacity of participants to drive their own improvement. Even if my intervention in your class did lead to a permanent change in your practice, further intervention would be required from me to elicit further improvement in your practice. My effort is like pushing a car with square wheels. It moves, but generates no momentum of its own.
3. In your PLC, you will (if it works well) be exposed to the ideas of colleagues and educational thinkers in a way that challenges and deepens your thinking about education, learning and teaching. You will reflect critically on the ideas of others, and have others challenge your thinking. This is the real meat of professional learning. You get none of this if I tell you how to change your practice.
4. I don't necessarily know how you can improve your practice. Nor do you! The best you can do is to reflect on your current practice, look at what research says, try something that has been seen to work for others, and evaluate the impact that the change in your practice has on your learners. This is how we work in PLCs. This approach puts you in control of your own practice.
5. PLCs offer you enormous professional autonomy. The price for this autonomy is your commitment to continuous improvement throughout your career, and to engagement in the systematic processes that drive that improvement. The alternative is to go through your career being told how to get better by others.
5. The new standard for full registration expects you to have a reflective, enquiring, research-engaged approach to your practice. PLCs will support you in developing this stance. My telling you how to change your practice will not.