Source: image of Remember America: public domain; http://commons.wikimedia.org/wiki/File:%22Appreciate_America_Remember%22_-_NARA_-_513871.jpg
In the process of memory and remembering things, information is taken in from outside of the world, it's encoded, and stored for later use. So the measure of effective processing of information and of memories, is if they can be retrieved later on, or remembered. So when we're talking about measuring memory, we're talking about how well a person can remember that information.
For example, when you're taking a test, you want to be able to remember all the facts that you studied, or else you won't have processed the memories very well, and you wouldn't have considered it an effective production of those memories.
It's important to note that memory isn't in an all-or-nothing process. You can partially remember things, as well. It's not just something that's taken in automatically, and formed in your mind.
For example, if you're taking a test and you feel like you know an answer, but you can't quite remember what that exact word is, this is what's called the "tip of the tongue" experience, where you know you have a memory, but you're not able to retrieve it.
So how do we measure effectively how memory actually works? Well, there are a few different ways that we do that. We're going to take a look at those in our lesson today.
The first measure of effective formation of memories would be what we call "recall." Which is to say, the direct retrieval of the information. Where the person reproduces the information that they learned. This is often done in an exact, or verbatim, sort of recall. Like if you were repeating a song or a poem you learned. You would just say exactly what the words are. And that's how you would measure if you had learned it correctly.
If some memory, let's say that poem, is only partially remembered, then you can often reconstruct that information based on logic. For example, if you're thinking back to your fifth birthday, and you don't have a specific memory of your mother being there, but you know that your mother was around in your life at that time then you would logically infer that your mother was there, even though you can't explicitly remember seeing her at that birthday. So you're putting together that information. This is also why, at times, there can be problems with the recall of certain events, because if we're putting them together, sometimes we might be making incorrect assumptions about that memory.
When we're recalling, let's say a list of information, there's a certain phenomenon that we find, where you can usually remember the first and the last items of something, better than you can remember the middle. This is what we call the "serial position effect." So let's say your husband or wife gives you a list to take to the grocery store. And you have to try to memorize it, instead of writing it all down at once. So you're more likely to remember that milk was at the top, and eggs we're at the bottom, but you're having a hard time remembering the stuff in the middle. That's because recall can be a very difficult process to accurately and exactly recount everything from memory on your own.
A more sensitive sort of process, something that's a bit easier for people in the reiteration or remembering process, is recognition. Recognition means being able to recognize information that was previously stored inside your mind. For example, if you're looking at a multiple choice test, then you would be using recognition, because you don't have to write down exactly what was said. It's not a fill in the blank test. That would be more recall. Recognition means just being able to see the information and say, yes, I realize that's the correct information that I remembered.
But it's important to note that this can lead to certain ideas of false recognition, as well. For example, in eyewitness accounts of crimes. When you're looking for somebody in a line up, let's say, you're more likely to think that you recognize a person within that lineup, even though the person that you're actually looking for isn't there. And it's an incorrect sort of thing you're saying. It's because you're looking for the information, you assume that it must be in front of you. So that can be an error in recognition.
Finally, we have relearning, which is the most sensitive process of remembering. Relearning means that a person tries to learn information that they had previously learned. So let's say that when you were a child, you might have learned what the 50 states were, let's say. And then later on in other life, you attempt to relearn what all of those 50 states are. Now you might not have explicit recall or recognition of learning all of the 50 states, but you'll find that, in fact, it takes you a shorter amount of time to learn that information than somebody who's learning it for the first time. That's because you still have some kind of memory of those things in the back of your mind. It's just not something that's explicit to you. This is why we say it's the most sensitive. Because it's something that you might not even necessarily be aware of.
So these are the three different measures that we have of memory and of retrieval.