Regarding the Sagan quote: these days, when everyone has Wikipedia in their pockets, "I don't know the answer" is not a valid excuse (for most questions that a child may ask).
"I don't know, but let's look it up" is an awesome answer!
It teaches the kid what their resources are, and gives them a handle on how to look stuff up independently in the future.
Plus, if you're going with (shudder!) Wikipedia, it means there's an adult to translate the ridiculously obtuse language that Wikipedia uses for all things science:
...The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields.[12][13] It has a diameter of about 1,392,684 km,[5] about 1
As a teacher, I wonder if it is possible to instill this skill into students the skills of rationality and critical thinking. I teach the third grade, and it is not immediately apparent how to apply this with my own class.
The problems I foresee are as follows:
In the sequences, it is suggested teachers should drill into students words don't count, only anticipation-controllers. How practical is this for an elementary school level? Also appreciated would be any ideas or experiences on how to do this, or how to combat the above problems. Hearing from other teachers would be excellent especially.