FLE4-- how do you create the "Big Questions" that initiate the knowledge building?

This post is not about setting up the FLE4 server software. This addresses the much more difficult task of creating the initial questions, AKA "Big Questions".  These big questions need to inspire students to engage in a progressive inquiry, building knowledge objects and motivating them to learn important science knowledge and skills. There are several criteria these Big Questions must meet:

1. Ideally, the Big Question must require the standards-mandated concepts and skills to solve them.
2. These Big Questions must engage students.  Bereiter says that we need to give problems that are of authentic interest to our students. Knowledge objects need then be marshaled and created as needed to solve these problems/answer these questions.   Students learn to value knowledge objects as tools, and gains skill in the use of these tools in solving problems in their lives.
3. The Big Question can't be to general or too specific.  As I have found from experience, if the question/problem is too overarching, to general, I as a teacher have a hard time managing the long and complex spiraling inquiry that is required to build a series of knowledge objects needed to adequately answer the Big Question.  Likewise, if the Big Question is too specific, little inquiry is inspired/required.

State mandated concepts and skills
The current unit of study is Evolution. The over arching, "sub standards" provided by the state for evolution are:

1. Genetic information found in the cell provides information for assembling proteins, which dictate the expression of traits in an individual.
2. Variation within a species is the natural result of new inheritable characteristics occurring from new combinations of existing genes or from mutations of genes in reproductive cells.
3. Evolution by natural selection is a scientific explanation for the history and diversity of life on Earth.

(You can see in the third big idea above where it says, "... is a scientific explanation..." is a nod by our ex-governor, Pawlenty to part of his constituency the anti-evolution lobby, here in Minnesota.)  At the bottom of the post I've listed the, "benchmark standards" that tells what students must be able "to know and do".

Big Question must engage students
I've used various strategies to create student buy-in to the KB process as well as find questions which students truly want to answer. I'm still searching for an ideal method though there might be none. Several years back I created 5 Big Questions that addressed the range of knowledge required by my students. For example, "What causes earthquakes?",  "How do humans decrease the destruction caused by earthquakes?" and more. This was easier and turned out to be fairly effective and was a good way for me to start to use KB in my classroom.  However, it's often good to have students do this hard, ambiguous collaborative work.  Therefore...

I've also presented students engaging material, such as eyewitness accounts and videos, of the phenomenon and had them record questions that came to their mind as they viewed this engaging material.  Students then wrote these questions on sticky notes and then organized them into groups. From there I've gone in 2 different directions:

1. I've looked at these groups of student-created questions and created that initiating question for each group.
2. I've had students create the overarching question for each group of questions.

And in either case I've used the student-generated questions in 2 ways.  First, I just told students to start engaging in the KB and they could add their specific question under the appropriate Big Question if they wanted.  They ususally didn't and their initial questions were usually lost.  The other way I've advanced is, upon engaging in FLE4 KB, I've directed students to type in their own, initial questions under the corresponding Big Question.  This was not good, however, that while it was logical, it was too circuitous and disconnected and did not lead to a good discussion. 

This time, I'm not creating an overarching question (which often is not a student's question but is instead a synthesis of their question), but instead choosing one student question to represent each group.  I then type all the rest of the questions in that group in the description for the post.  I'm careful to attribute the questions to specific students by including their first names next to their questions.

Big Question can't be too general or too specific
While I've created many appropriately-leveled Big Questions, I erred on the side of 'too general' last year with the question, "Where do Humans and the other about 1.8 million described species on Earth come from?"  One class had over 200 posts to this question--it became too ungainly for most students to really get a grip on it.  We'll see how students deal with the questions I've selected in the current round of knowledge building to serve as the Big Questions.  For my period 6 class they include:

1. Ben -- how are new organisms created?
2. Thalia -- how do they know when a skull comes from a female or male?
3. Marilu -- how do we know that evolution has happened?
4. Xavier -- when they say, "2 million species" do they mean like a regular cockroach and a Madagascar hissing cockroach being 2?
5. Somsanith -- why did Darwin choose to study nature?

Normally I would have carefully crafted the wording, but what I loose in precision by quoting student questions I more than make up on student buy-in, I believe.