I want to talk a bit about an outdated concept that I still see used today that is really not good in many circumstances, and represents a mode of thinking that causes the user to make a lot of (sometimes really bad) mistakes.  That is the concept of raising for information.

When I ask a student "why did you raise here?" and they reply "to see where I was at", I cringe.  This type of thought process is used by the student uniquely in situations where they have a good but not great made hand, something like top pair most commonly.  Obviously if they had the nuts or nothing they would know "where they're at".

The problem with this mode of thought is two-fold.

1) Often times they are doing it in situations where the information won't be helpful anyway... i.e. if the opponent folds, you were ahead, and if they don't fold, you're behind.

The primary reasons to raise are for value or as a bluff.  For value means worse hands will call, and as a bluff means better hands will fold.  Information can at times be a nice bonus in the deal, but should never be the primary reason you're raising.  If you do it in a situation where all worse hands will fold, and all better hands not fold, then you are not making a good wager.

Example:  A tight-aggressive player opens for a raise in early position, and you call on the button with A9s.  It's heads up, and the flop comes A33 rainbow.  The TAG continuation bets and it's up to you.  This is a classic "way ahead/way behind" scenario... meaning if we are ahead, the opponent has few outs to beat us (in this case usually 2, to hit his big pocket pair).  And if we are behind, we have few outs to beat them (we need to hit our kicker vs. his bigger ace).  In most cases the best play is to call, as if we raise, he will fold all the hands we are beating, and never fold those beating us. Where as if we call, we can possibly get an additional street of value later in the hand from KK/QQ, and we can hit our kicker or catch an A or 3 vs. his AK/AQ hands, an opportunity that will be denied us if we raise and he comes back over the top.  We will certainly get good information from a raise in this particular situation... if he folds we had the best hand, and if he doesn't fold we are in very bad shape... but that information isn't particularly useful as we cut our value in both cases to obtain it.

That leads me to the other point.

2) The information we get often won't be accurate, which can lead us to making even more mistakes.

The whole concept of "raising for information" once was sound.  It stems from a time when people, for the most part, responded to this action in a way that was honest with their hand strength.  In todays game however, this is hardly ever true. 

Example:  An unknown player open raises from middle position, and we call on the button with QTs.  The flop comes Th8h7s.  The unknown player continuation bets, and we decide to raise "to see where we're at".  He calls. 

Where are we?  I have no idea.  Maybe he's unsure of the strength of his JJ or AT.  Maybe he's got 99 or QJ or hearts and is calling on the draw.  Maybe he's got JT or T9.  Maybe he's getting cute with a set of 7's and is going to put in big turn action on a safe card. Our goal of figuring out where we're at has failed, since the unknown opponent could reasonably call both with many better and many worse hands.  All we've accomplished here is to bloat the pot with a hand strength that doesn't really warrant it, which will make our life on future streets much more difficult and sets us up to make a big mistake later in the hand.

What if he had re-raised?  Does this tell us where we're at?  20 years ago it would have, we're crushed and can comfortably fold.  Today things aren't so easy.  Players are so much more aggressive in general, we can't be confident we're beat by a reraise. We can be facing this action by any number of draws, by a hand like JT against a player that over-estimates this hand strength or thinks we are just raising on a draw ourselves and wants to "protect his hand".

Raising for information can be valid in some situations, but those come much more few and far between in today's modern poker world.  If you are a player who does this regularly, I would encourage you to try taking yourself out of this mindset, and before raising ask yourself the question, is this raise for value or as a bluff? (Will worse hands call it, or will better hands fold).  If the answer is no to both questions, or you're not sure, then strongly consider not raising.  Think about your aggressive actions in this manner, and treat information as a secondary consideration, and you'll likely see your results improve with this shift in the decision making process as you'll be making betting and raising decisions for better, more sound reasons.