Guided Inquiry
I was prompted to write this after reading the Random Access Mazar blog on inquiry learning. I too have been trying to wade my way through the multiple definitions of inquiry. It does seem that everyone you talk to has a different definition. One of the main conclusions I have come to is the need for guided inquiry, especially for students new to the inquiry process. I work mainly with primary school students from age 7 to 12 and leaving the inquiry completely in their hands when they have had little or no previous experience of the inquiry process would be a recipe for disaster. The same would apply to older students new to the inquiry process.
As Vygotsky(1978) tells us, there is a need to scaffold learning, to work with students in the zone of proximal development “the distance between the actual development level as determined by independent problem solving and the level of potential development as determined through problem solving under adult guidance or in collaboration with more capable peers". As pointed out in the Random Access Mazar blog "Inquiry-based learning methods (as described to me thus far) appear to undervalue the resource that the instructor really is to the student." This need not be the case. Herron’s Four Levels of Inquiry (thanks to Artichoke for pointing me in the direction of this one.) give a nice overview of how levels of teacher intervention can vary according to the task and needs of the students.
I think Jacqueline and Martin Brooks (1993) make a very good point on this issue when they state:
Posing problems of emerging relevance is a guiding principle of constructivist pedagogy. However, relevance does not have to be pre-existing for the student. Not all students arrive at the classroom door interested in learning about verb constructs, motion and mechanics, biological cycles, or historical timelines, but most students can be helped to construct understandings of the importance of these topics. Relevance can emerge through teacher mediation. (p35)

Bruner (1971) also comments on this issue:

It is just as mistaken to sacrifice the adult to the child as to sacrifice the child to the adult. It is sentimentalism to assume that the teaching of life can be fitted always to the child’s interests just as it is empty formalism to force the child to parrot the formulas of adult society. Interests can be created and stipulated (p. 117).”

There is also a tendency for schools to try and impose a “one size fits all” model of inquiry on their staff and students. While I see nothing wrong with schools or other educational institutions developing their own models of inquiry provided it is done collaboratively with staff (and in some cases students), teachers do have to formulate a flexible model of inquiry that works for them and their students. As Joan Vinall-Cox points out in her blog “No theory is applicable in all situations in the classroom, and theories that undermine the personal practical knowledge of teachers, are destructive” If the school model is flexible enough it will be able to be adapted by teachers to suit their teaching style and by students to suit the task.
Inquiry learning can and does work in classrooms, I know because I’ve done it. When it is carried out effectively it results in engaged and motivated students who construct knowledge and understanding of concepts related to topics of interest and/or relevance to them.

References
Brooks, J. & Brooks, M. (1993) In search of understanding: The case for the constructivist classroom. Virginia: Association for Curriculum Supervision and Development.
Bruner, J. (1971). The relevance of education. Cambridge, MA: Harvard University Press. NY: Norton
Vygotsky, L.S. (1978). Mind and society: The development of higher mental processes.