While I'm running around hither, thither, and yon today, here is the question I'll be pondering. Perhaps you wouldn't mind thinking about it as well---and offering any ideas you have in the comments?
How do you know if something is developmentally appropriate?
The "something" could be a toy, behavior, or a grade level standard. Games may be labeled as being good for those "8 and up"...all 8th graders might be expected to be successful in algebra. We can look at classroom concepts and break them down into smaller steps and bites, but that doesn't necessarily mean that we just work backwards from there and assign each piece to a different grade level.
I don't really want to get into whether or not the labeling aspect is a hot idea (that's a whole 'nuther post)---what I'm more interested in knowing is how you decide. Are there references or resources available? I'm sure that experience (especially if you've worked with a particular age group for a long time) comes into play.
What goes into the decision making?