I recently came across an article written by Malcolm Gladwell in the New Yorker called "Open Secrets". This seems to be about the fall of Enron and the prosecution of Jeffrey Skilling, but it also discusses an interesting way of thinking about problems. The article sets forth a dichotomy - a problem can be viewed as a puzzle or a mystery. These terms are a bit counter-intuitive and describe concepts that don't quite jive with what you might think those words mean.
So let me define the terms here. In the article a puzzle is a problem which has a definite solution where new information will yield an obvious answer. A mystery is a problem where we may in fact have too much information and may not come to a satisfactory conclusion. Gladwell argues that it is critical that we identify the particular type of problem we face (puzzle vs. mystery) because if we approach a mystery like a puzzle we will utterly fail to address it adequately.
If I may, I'll offer this analogy to make this clearer. Suppose you have a 1000 piece puzzle but are missing 900 of the pieces. You can approach this problem in two different ways - One person may decide to go looking for the missing pieces - maybe they fell out of the box, maybe they got put into a different box etc. Another person may realize that finding all of the pieces is now a fools errand, but careful analysis of the pieces we do have could reveal most of what the puzzle depicts.
Now lets complicate matters further and imagine that instead of just missing 900 pieces, you also have 3000 pieces of other puzzles mixed together with the puzzle you are trying to solve. Now if you choose to go looking for the missing pieces you may in fact find pieces that fit another puzzle altogether instead of the puzzle you are interested in.
I think this approach is a really valuable way of looking at scientific investigation. Perhaps just as valuable as the scientific method. Of course the scientific method is a different way of looking at problem solving and provides a much more detailed methodology.
There are a lot of scientists who approach scientific problems by hunting for the missing pieces (piece hunters). This usually includes people who specialize in a particular technique (remote sensing, isotopic analysis, TEM, etc.). In their world, their technique will provide the key missing pieces because the measurement has never been done before on whatever sample they are analyzing. Of course once they have found the piece (made the measurement using their favorite technique) they need to figure out how it fits. But since their entire effort has been focused on just finding the piece, they frequently look for an easy connection and write their paper.
There are other people (piece thinkers) who instead approach scientific problems by just examining the pieces (data) that has already been collected. These people find interesting connections that haven't already been made, and thus can make discoveries without finding out anything new. Of course this is usually difficult to do, since despite my callous description of the piece hunters, they usually have made most of the connections already.
Now, I don't think this dichotomy is a black and white thing. I think many of the piece hunters also spend a lot of time trying to understand the pieces already collected, and many of the piece thinkers also do their fair share of finding new pieces. Obviously, the most powerful science is done where both methods are combined and an investigation is targeted to find a specific missing piece. The problem for the piece hunters is that because of their technique specialty, they can only find certain types of pieces. If the targeted piece isn't the right kind, then they are out of luck.
Applying this whole concept to Mars, if we imagine Mars as a puzzle. We definitely have started with only a very few pieces, so it makes a lot of sense for us to focus our energies on obtaining new pieces to the puzzle. However in the last 10 years, this has resulted in a multitude of pieces - many of which don't fit into our specific Mars puzzle. So now we find ourselves in a position where piece thinking may prove more fruitful than piece hunting. In addition, I think it is time that the piece hunters sit down at the table and start putting more effort into understanding the pieces they've already collected, than simply collecting more for the sake of collecting more.
So switching back into the Gladwell terminology, I would say that Mars has changed in the past ten years from a puzzle to a mystery. More innovative thinking is needed to approach and identify the key scientific questions - and design better investigations.