This is a very interesting article which I recommend all active small-cap investors to read, very illuminating:
http://www.capitalspectator.com/a-revelation-for-small-cap-investing-strategies/
For those who are hard-core and want the source academic paper, here is the link to that as well:
Size Matters, If You Control Your Junk
Conclusion:
Small-Cap investing will outperform large-cap stocks, IF you stick to high-quality small-caps. Better still, find small-/micro-cap stocks with a high QV StockRank, in order to harvest both the small-cap and value premia!