You can call it erratic action or some other terms, but if you are not catching any fish you should change what you are doing.  My personal opinion is that fish have periods when they don't bite and they have periods when they do bite.  It is really difficult to determine which phrase they are in.  So if you are not catching fish change something (e.g. lure, color, depth, location, speed of retrieve, method (trolling, casting or jigging)).  The main thing is that you keep the faith and keep trying.  One thing is for certain if you don't have a lure in the water you are not going to catch any fish.  Obviously, certain areas on the lake will be better than others.  To find the better areas require a certain amount of time.  Even if you find a good area it may not be a good area later on in the day or the next day.  If you fish an area often enough general patterns will develop.