Do speleologist explore a new cave passage before mapping it?

It is accepted practice in the speleology community that if you believe you are in unexplored passage, that you should take the time to survey it properly before continuing down the passage. There are a few exceptions to the rule. Such as, you were not expecting to find virgin passage and didn't bring survey equipment. If your intentions are to map the passage later, then a short scouting trip up the passage will give you a good idea what survey gear will be needed. You won't get much credit for the discovery of the cave or passage unless you publish a map of it in a caving journal.