We have 2 in school now and we take them out every year. With my dh's work schedule he can't take a summer vacation due to hurricane season. Besides we like it better at WDW during the winter and the rates are better. We always give the teachers plenty of advance notice that we are going on vacation so that they can decide what work needs to be made up. So far the teachers have been very understanding and the only work they have had to do was to send their classes postcards and to keep a daily journal. No make up work or tests.
The nice thing is that we treat all family vacations as learning adventures. Where else can a kid get so close to a gorilla that they can put their hand up to the wall seperating them? Or come nose to nose with a hippopotamus? Because of the way that we "do" Disney, our kids get to travel to Asia, Africa, Morrocco, Japan, Canada, Mexico, Norway, France, England, China, and study American History. They can also delve into their imaginations and learn about fantasy. My dh, being the engineer that he is, gives annual lessons in the dynamics of a roller coaster and why you don't fall out. This past trip he was telling the girls while in line and everyone around him was silent as they listened to his explaination.
Our kids have learned about their bodies, ecology, animal preservation, history of communication (which my youngest dd still talks about), space, and how fossil fuels come to be and they didn't sit through boring lectures to do it either. They have eaten foods from cultures that they had only read about in books (and found that it is tasty!) Seen people of all ethnic backgrounds, and not just the cast members either! WE were sitting on the monorail next to a woman from India and my oldest daughter asked me why she was wearing different clothes and why she had a dot on her forehead. The woman was kind enough to answer all my daughter's questions and even bestowed a blessing on her! (Which mom found tres cool!)
I could go on and on about what experiences my children have gained from a trip to an "amusement park" and I would be more than happy to if anyone wants to know how they can make their next trip to WDW a learning experience that a missed week of school could *never* make up for!
