So the other day my uncle and I got on some nice schoolers in about 15' of water on a flat adjacent to a steep drop off. We were catching almost every cast for over an hour, but they were all really small. It was a blast, but was wondering what you do if your wanting to find some better quality.

Is it better to just keep throwing at the smaller sized school hoping a big girl will get in the mix, or would you abandon the spot in search of a different pattern?

Where would you go? I'd stay and maybe change lures, depth or both. You might move to another spot and another spot and another spot and then it's time to go home. I think the common response I hear is don't leave fish to find more fish. JMO

There has only been a hand full of times on a spot with lots of small fish that I hooked into a big fish. They usually separate themselves form the pack. A couple of times sense the generation of side scan, I was able to get off the school and found a group of bigger Bass close by. I have done a lot of looking around such schools; but with not much luck.

They are fun to catch when you are getting one every cast and hard to leave that kind of action. I would definitely stay and wear them out. I wouldn't get my hopes up though. Doing this in 15 ft. of water there is even less of a chance finding big ones close by. The first place I would look would be below them on that deep slope.

Now, many times I have found smaller shoreline fish and moved out to 6 to 12 ft. of water and found larger fish. The cover on all of those shallow water spots was very heavy and provided enough spots for the larger fish to hang out. It is all about the right structure and cover to support both sizes of fish in one area. Any draw or gouge in the shoreline can separate the two. You might find small ones on one side of the draw and big fish on the other side. Such draws work as a funnel point leaving the creek channel. The big fish went one way and the smaller ones when the other.

In really deep water on Amistad I have found them stacked against deep ledges over 100 ft. of water. There will be a band of small Bass, say at 30 ft. and just under them at 45 ft. a huge group of large fish. There was always a good bit of space between the two schools of fish and they stayed separated. I done thank Big Bass like the way smaller fish respond to food with there fast and furious action while in competition for bait. It is kinda like adults who do not enjoy being around a large group of kids at a party. They set back and watch but try not to get too involved.

Abandon

If fishing a tourny then get your 5 and try to cull. If not really upgrading then you gotta go. Fun fishing I'd stay a little longer and try out different baits I hardly use.

Fun fishing, I'd stay until it just got boring. I'd also try some other techniques that I normally don't use and try to build some confidence in them.

Dont get me wrong, I loved every minute of it, but was hoping I would eventually get into something bigger. We searched around the drop off and other areas but the bite shut off. As soon as we moved back onto the flat the little ones would start biting again

Big bass are smart, fat, and efficient; most likely they won't be in that smaller school of fish spending all that energy chasing/feeding on bait fish.
Now, they might be under them lazily gorging on injured bait as it falls to the bottom, so it doesn't hurt to throw a bigger spoon, jig, or lightly weighted or crigged large fluke where you were catching the small scoolers. If you are really good with electronics; drifting over the smaller school could give you some info.

That being said, smaller fish eating suggests that it's also good time for larger fish to be eating.

The first thing I'd do is try that drop off next to the flat where the small schoolers were being caught--especially if there's some deep cover on the drop off.---see you did that. Then I'd follow the drop off/creek channel to the nearest point paying close attention at creek bends.

This is everything. This is how I've built confidence in every new bait or technique since the first.

If I'm fun fishing and I'm on em, I put away my confidence gear and pull out my insecurities and unless them on the dinks.

Now I'm too confident in my entire tackle box and bam one of those "ain't no fish in this lake guys" though so... Its a fine line haha

It's definitely a great time to try different baits. The little guys liked just about any soft plastic I had on a c-rig. Nothing else worked though that day