In active learning, students have free to express their opinions, so in this condition, is leadership of the teacher still needed? and how the leadership should be made in that condition?
The essence of leadership is helping a group achieve a goal. The goal of teaching is expressed in the student learning outcomes. Students, even in an active learning environment, will not achieve the learning outcomes without guidance. The teacher must provide the leadership necessary to achieve the goal.
In an educational environment, a transformational leadership approach is generally greatly appreciated.
The assumption in the question is that one simply decides to adopt an action learning model and snap, it will happen. Children have to be led to this level of agency and that takes time and any progress depends on the motivation and psychological maturity of the students.
As a primary school teacher, and principal, teaching across the curriculum I adjust my level of leadership based upon the subject taught. I have been the 'sage on the stage' and the 'guide from the side (see Martina's comments). And, as David said transformational leadership is a desirable outcome, especially when developing independent learning competency, but sometimes a more bureaucratic mindset is required.
Check out John Hattie's (2009) 'Visible Learning: A synthesis of over 800 meta-analyses relating to achievement' Routledge. He observes that teacher as facilitator generates an overall effect size of 0.17 whereas teacher as activator brings about an overall effect size of 0.60 (p. 243).
What is more likely, and what happens in my school much of the time, is what Markovic suggests; the teacher is a manager. That is, students are consulted, goals are set, plans are made, and everyone has expectations around acceptable behavior. And the the instructional approach matches the classroom context at that time, in that place, for these students. If that means active learning then so be it.
Thanks for all your helpful answer. So, the main point is that teacher should have leadership to help students grow their potency and talents as instructed and aimed.
Yes. I think that's it. Active learning might the your aim, and you pitch your instructional model to achieving that.
You may begin by modeling the desired approach (you do - they watch), moving then to a shared approach (you do - they help), then to a guided approach (they do - you help), finally finishing with independent agency (they do and you leave it to them - coaching only when and where it is necessary).
It is an aspirational goal and depends very much on the readiness of students to take up the challenge of independence and on the readiness of the teacher to hand over 'control'.