We don't watch too much television in my household. In fact, some days we don't even turn it on at all. But since it has been cold lately, I have let the kids watch it some. My six year old either watches videos, movies, or the Disney (R) channel...that's it. I don't trust what is on other channels, sometimes even the cartoon channels aren't so safe, at least by my values! My son either watches PBS or Elmo (R) videos. Even then, it is for limited amounts of time. Of course, as I am typing this I can just hear him saying "Elmo, Elmo!".
I don't believe that T.V. in and of itself is bad, just when it is in excess and the wrong show! Small children don't need to be watching violent or sexual adult programs in the evening! They also don't need to be watching too much educational television programs. Why? Well, there isn't much socialization, learning to wait, playing, gross motor activity going on during the average T.V. program.
But what about if you watch the show with your toddler, repeat simple words, and ask questions? Then, I think it is fine. With preschoolers and elementary age children, they can learn nice facts such as while watching shows about animals. Some of them also need time to relax after a long day of school. But of course, that doesn't mean sitting at the television for 3 hours in the evening!
Some videos geared toward infants and toddlers claim to "make your baby smarter", but I think that has never been proven, and in fact one big company was forced by the courts to reimburse people for their money if they so wish, because it wasn't able to prove it help children get any smarter! There are some baby videos I like more than others. For example, Brainy Baby (R) does a better job over some other popular companies. Why? Because their videos tend to say words more often, not just music. One video I have in Spanish from Brainy Baby (R) shows a picture of various dogs and says "perro" over 6 times, whereas some other brands may only say "dog" or "perro" once. So, the point is to stimulate the language center of the brain. You may want to sit next to the child, and also say "dog", then show a picture in a book of a dog or have a toy dog nearby. This way it is more interactive, which makes learning more likely to occur.
When going into homes as an occupational therapist, I get to see many families' routines, including television watching habits. If the mom is constantly watching her T.V. programs during the day, she is less likely to be speaking to her child. Some families have the T.V. on all day, and may even eat meals while watching it. This has actually been proven with research for people to over eat and make poorer food choices, because they aren't focused on when their bodies tell them they aref a full, instead they are distracted. This coupled with less activity is a recipe for childhood (and adult) obesity! Also, I shouldn't be having to encourage a family to reduce their T.V. watching down from 8 hours a day, especially when the child's language and social skills are severely delayed such as with autism.
So, I think T.V is fine as long as it is not the "babysitter" and is in small increments of time. And for toddlers, I approve of T.V. when it is more interactive.