Using a Slow Cooker

My inclination would be yes. If you are using a slow cooker that would not normally hold a whole recipe, or it would be very full, then you should half the recipe. Cook it for about a third of the time and see how it fairs. If it doesn't seem to be fully cooked go the rest of the time. When you have an appliance that you are either not sure of or it has cooked incorrectly in the past you need to adapt to the unit.

For example I have a microwave that brings a coffee cup to a rolling boil for just a minute. A half a minute doesn't really do the coffee justice but we found 45 seconds does the trick OR we can do a minute and turn down the strength of the microwave to about 2/3 it's normal power.Once you use the slow cooker a couple times you'll understand exactly how it does a job and you'll be cooking foods perfectly every time.