The danger of over-checking your dish.
Believe me, I understand the desire to take a peek at your meal while it cooks. After all, it is making your house smell AMAZING for 6 hours... The King of Crock himself is "guilty" of frequently checking his chili, stirring for the sake of stirring.
Truth is, unless it specifically says in your recipe to stir your dish, resist. There is very little reason to check the food. So don't.
The slow cooker relies on the the heat building up under that lid. Like a pressure cooker, the air at the top actually heats up and cooks the food from the top. Each time you remove the lid, you allow that hot air to escape and force the slow cooker to start over again.
Commit yourself to leaving the crock covered until AT LEAST half of your time has expired. During the second half of cooking, only check it when you must. Your food will cook quicker and more evenly.
You won't be disappointed.
Next Up: Roast Beef