Reward "DNK" When You DNK
Of course you don't want to reward "I didn't bother to ..." laziness, but you do want to reward—Big Time—truth-telling. Hence, cheer publicly the person who admits, in front of a boss, that he or she "does not know" the facts here, or the answer to this or that. In fact make a game (serious game!) out of identifying the "DNKs" regarding any analysis or proposed action. Frankly, good inventories of DNKs may be far more important to success than inventories of DKs.