Judging a Patch by its Scent

In the first instance, when you know what you’re looking for and where to find it, you have defined your patch and you have a pretty good idea what route to take to find your specific piece of information. In the second instance, you don’t know which patch you’ll find the piece of information in. This is where classic wayfinding behaviors and information scent can play a critical role in seeking information.

When you’re not sure which information patch contains the right information, you have to judge each patch by its relative scent. This pretty much guarantees you’ll visit more than one patch, which for our purposes translates to websites. You’ll try to do a preliminary assessment of scent based on what you see on the results page, but you’ll reserve most of your judgment for when you click through to the site.

Looking for Greener Grass

One of the interesting aspects of optimal foraging for food is that there are costs to move from patch to patch. You have to literally assess whether the grass is truly greener on the other side of the fence, or whether it would just be a senseless waste of effort. Most animals have a highly developed heuristic instinct about when the time is right to move on to the next patch. Eric Charnov, who reached out to me (I’m still following up with Eric to get a follow up interview for a future column) after the original information foraging column, called it the Marginal Value Theorem. In a nutshell, Charnov’s Theorem says that we decide how long to stay in a patch based on how rich the current patch is and how distant the next patch is.

One of the challenges of the Marginal Value Theorem is that we often have no way of knowing what the “richness” of the next patch might be until we commit to expending the energy to go see it. We risk the effort based on our assessment of the current patch and the hope that better patches lie ahead. And the risk lies in the fact that it takes energy to move from patch to patch. Patches are separated by distance, so we physically have to invest the energy to move from the patch we’re in to a future patch. The degree of risk lies in the distance to the next patch, our expectation of the richness of that patch and the value of the patch we’re currently in.

Patch Hopping with Search

But online, the internet is non-dimensional in the traditional sense. There is no distance, the only dimension is time. How much time are we willing to expend to find the next patch? And search gives us the ability to greatly reduce the time needed to navigate from patch to patch. We structure queries to define the “diet” we hope to find in each patch. We then can click through to see if the scent matches our definition of diet.

Remember, here time is the resource we hope to conserve, so these explorations from the search page are very quick. We can visit a number of patches in seconds. We define the diet (what we’re looking for) and start down the page visiting the most promising patches. Based on user research we’ve done at Enquiro, we typically take 10 to 12 seconds for the first click from the search results page, and spend about 15 seconds assessing the scent on the pages we visit. Because we are programmed to save effort, if we visit a few patches and come up short, we’ll use a new query to define a new collection of patches. Because we have no defined notion of which patch will be the right one, we have to use shortcuts to judge each patch quickly and efficiently. We have little patience for unpromising patches.

Of course, our level of patience also is determined by how rare the prey is we’re pursuing. If we believe it should be rather plentiful, we also believe the scent should be easy to pick up. But if our prey is elusive, we’ll be more patient in our quest to pick up its scent. These are the searches that will drive us to the second or third page of results.

We Don’t Consume Information

If we find a rich patch, we file it away for future consideration. This is another area where information foraging diverges from biological foraging. Looking for food is a zero sum game. If we don’t eat the food we find, someone else will. So when we find a rich patch, we stay put until we eat as much as we can (or until a richer patch beckons). But online, information is not really consumed. Even if we use it, it’s still there for the next visitor. There’s no risk to move on and find other information patches. This is where traditional wayfinding strategies come in. As we explore for information, we define the landscape based on the richest information patches. These become landmarks which we return to again and again. So we quickly use search to define the best patches and tag them for future reference. Then, we return to them at our leisure, knowing the information will still be there, waiting for us.

Next week, we’ll looking at the third state of information seeking, where we don’t know what we’re looking for or where to find it, and how it impacts our search behavior.


Copyright 2008 - Enquiro Search Solutions.