COMPUTERS AND HUMAN BEHAVIOR

[Music] you ready okay oh no you got to put the two of them together you see you got to keep them you got to keep them that's quite a problem isn't it this is a seven-year-old child attempting to solve a problem well what do you see what are you looking at i'm trying to figure out a way to do it a human being thinking and this is an electronic digital computer a man-made machine which under man's guidance is able to solve certain problems have they something in common the human being of the machine can computers help the psychologists to understand the workings of the human mind [Music] how man goes about solving problems how he learns from experience how his memory can store information and refer to it when it is needed how he draws conclusions and acts upon them the mysterious processes that make the human mind the unique tool that it is this is what psychology is concerned with recently some psychologists have found that electronic digital computers can give them new insights into man's mental processes they have begun to use computers in a variety of ways some of them fairly obvious and predictable others far more intriguing at the carnegie institute of technology in pittsburgh there is a group of scientists exploring this new frontier of psychological research they are dr alan newell institute professor of systems and communication sciences dr herbert simon associate dean of the graduate school of industrial administration and professor of psychology and dr bert green head of the department of psychology computers are used by psychologists in many different ways they can do obviously in psychology as in other sciences the statistical analysis of experimental data today scientists are submerged in a sea of data bogged down by endless calculations this work can be done swiftly and efficiently by computers computers are also useful in creating stimuli for research in psychology the computer can actually make the stimulus material for use in the experiments and can even run the experiments in some cases i for example have been using computers to produce stimuli visual displays for use in an experiment in visual pattern detection computer pictures have been very helpful in studying the visual perception of depth depth perception depends on many cues differences between the images to the left and right eyes brightness differences size differences and motion motion is very important for depth perception stationary dots have no depth but with movement their depth becomes apparent the computer pictures have isolated motion from all other cues to depth so that its relative importance in depth perception could be evaluated [Music] computers can also play tunes and dr benjamin white of mit has used computer tunes to study auditory perception in much the same way that computer pictures were used to study visual perception dr white was interested in how people recognize familiar melodies what cues do they use how important are rhythm and pitch differences for recognition to find out familiar melodies like yankee doodle or swanny river the distorted tunes were recorded on tape and were later played for human subjects to identify [Music] number 33. [Music] by finding out how much distortion can be tolerated the experiment helps us to understand more about the complicated process of human perception [Music] the computer indeed is very versatile it can help the psychologist analyze his data and as you have just seen it can help prepare materials for his experiments but there is another application of the greatest importance for computers in psychology they can help the psychologist create new theories of human behavior before we proceed however let's have a clear understanding of what a computer is and what it is not in its ordinary uses it is very much like an abacus or like a desk calculating machine it can perform simple operations addition subtraction multiplication division but being an electronic device it performs at incredible speeds but a computer is fundamentally not just a number manipulating device its basic elements its circuits may be made up of vacuum tubes or transistors and these elements can be in either of two states like this electric light bulb which can either be on or off in its usual uses the computer interprets on as a number say one and off as another number and in fact uses a number system in which it builds up the ordinary ten digits out of the simple elements zero and one but we can just as well consider on as yes and off as no or any other kind of choice between one thing and another a computer then is a quite general symbol manipulating device some psychologists believe that human behavior is also a matter of manipulating symbols for example a human may solve a problem by storing symbols by associating one symbol with another and by comparing different symbols these psychologists proceed in the following way they give the human being a task then they create a set of rules a theory to explain how he should do the task they give the computer the same task and the same rules finally they compare the behavior of the computer with the behavior of the human being to see how they match consider the problem of memorizing how do people recognize names when they read them how do these names bring up associated memories to find out let's look at one of the oldest experiments in human memorizing how we learn to associate one word with another i'll be controlling the drum from over here bob the syllables will appear in the lighted windows in front of you this is the method of paired associates you were to give the second syllable as a response when the first syllable the stimulus is shown to you in real life memorizing depends on many things not only how often the material is shown to the subject and how it is shown but how meaningful it is to him and how familiar the first syllable of each pair will appear in the window for a time before the second syllable this will permit you to announce your response before it is shown to you are you ready keg tag luke rom rom till grill grill pen keg loop brav rom till grill grilled pen we need a task that will be of comparable difficulty for different subjects so for a standard memory test in psychology we use nonsense syllables nonsense syllables have been used in psychological laboratories since about 1885 and they're still very much in use real pem grill pen keg luke keg luke as you can see after a few trials the subject memorizes the paired syllables correctly but how does he do it what mental processes are involved in that brief second after the word real appears in the left window and the subject responds pam dr herbert simon at carnegie institute has theorized that memorizing is actually a series of symbol manipulations if true the computer should be able to duplicate this human behavior and thus test the validity of this theory here the computer is presented with the problem of matching the correct pairs of nonsense syllables [Music] it rapidly completes the task but how what happened inside the computer and what does it suggest to us about human memorizing the program that we have constructed as a theory of human rote learning is called epam for elementary perceiver and memorizer epam was devised by dr edward feigenbaum and myself as a theory of human verbal learning epam provides the computer with rules that allow it to construct a set of tests which it uses to distinguish among the syllables and give the correct response now we have here a graphic representation of what goes on inside the computer epam does not deal with the way in which the subject actually sees visually or perceives the stimuli we give epam gives the computer uh a set of coded tests to distinguish among the letters like uh among the syllables like curve in first letter but now let's see what epam will do what the computer programmed with epam will do if we present it with a particular stimulus let's say real first it applies test one is there a horizontal line in the first letter no there's not go to test two is there a curve in the first letter yes there is go to test four is there a horizontal line in the third letter yes there is so we get the stimulus image real and associated with it is the response cue p dash m this is identified in the same way test one does it have a horizontal line in the first letter no apply test two and have a curve in the first letter yes apply test four does it have a horizontal line in the third letter no apply test five doesn't have a diagonal line in the first letter no so the response syllable is hem and epam given the stimulus real has produced the response hem the theory of memorizing that epam formulates claims that human beings build a structure of tests to identify syllables and associate cues with the tests to find the correct response of course the individual tests in their arrangements may differ from one individual to another but the general structure remains the same the behavior of pam agrees very well with the evidence we have of human behavior epam even makes some of the same mistakes that humans make for example it shows a tendency to oscillate that is to make a correct response to a stimulus on one trial but an incorrect response to the same stimulus on a subsequent trial keg luke romney wrong till drill pimp drill pimp is certainly not the last word but it may well lead us to a complete theory of verbal learning the computer has given us a way to formulate a psychological theory just as mathematics has given scientists in other fields ways of formulating physical theories can the computer do other things that humans can do can the simple yes no choices that epam uses to tell one symbol from another and to link one with another be combined with other processes to explain other kinds of human thinking probably the most exciting experiment now being done with the computer deals with complex mental processes the processes that man uses to help him solve problems the computer theory explaining this is known as gps meaning general problem solver it was devised by dr herbert simon and his colleague dr alan newell at the carnegie institute of technology gps provides a theory explaining the behavior of this child the problem the child is trying to solve is relatively simple for a seven-year-old his job is to make a line of blocks similar to the line of blocks in front of him but in doing so he must follow certain specific rules he may add two white blocks or he may add two black blocks or he may take away one white block or take away one black block those are the rules he must follow so i'm gonna so we got a problem here now i'm gonna give you a little puzzle so i've given you a white one and a black one and a white one and a couple of black ones and a white one and now you got this one to start with and you want to make a line that looks just like that okay so you can do these things now how you gonna do it gonna add two white ones and take away the white one and add two black ones and take away one that's what you can do so now i've given you this line here with the black one and this one and this one yeah and i've given you this and you got to make a line here that's just like that i want you to try some things no but i can't put this oh that's right you can't put that there what can you do if you could put that there that'll make it all right wouldn't it what can you do well that's a real fine idea but the rules just won't let you do it like that remember what i said you got to go ahead and put just two black ones you can't spread them out like that or two white ones or take away a fly or take away a fight so that was a real bright idea though then it's impossible well no it's not impossible there's a way of doing it given these rules well you must be able to do it with some of these remember i said you got to keep them together remember i said keep them together that won't work out that's right yeah that's quite a problem isn't it then you cheated what what do you mean i cheated because you can't um no no i just set those up just so you could build that line like that that's what i did well what do you see what are you looking at i'm trying to figure out a way to do it well what do you see when you're trying to figure out what the problem is all i get is you put two take away one and you put two white ones down and take away one then you put two black ones down take one one and then put two white ones down and take away hey look at troubles there uh-huh now what are you gonna do i'm gonna take this off and then get two black ones and take away one and then i put two white ones down take one yeah now you got it well very good billy very good the problem this child was working on requires what we psychologists call complex integrated behavior the putting together of many separate pieces of behavior to do a single job just as an architect's plan integrates the behavior of carpenters plasters and electricians to produce a building dr simon was telling us about epam which is used to make simple associations and tell things apart but billy here not only had to learn these four rules and distinguish those patterns of blocks but he had to select out the right rules in the right orders to build up that arbitrary pattern now this is an easy job for an adult easy to keep track of all the things easy to spot the difficulty and solve the problem but it wasn't easy for billy even though he finally made it let's first look at the way an adult would solve the problem or rather the way this computer program gps would do it we built gps to describe the behavior of college students doing elementary problems in mathematics and logic now one of the main features of human problem-solving behavior is its generality the fact that a man can do a wide range of problems once you've explained to him what the problem is we've tried to make gps general too which means that it should be able to work on different problems once it's been given the necessary specific information indeed that's why it's called the general problem solver so we certainly ought to get it to be able to work on a simple problem like this so let's give gps exactly the same problem that we gave billy that is there'll be symbols in the computer's memory to represent these four rules and there'll be some symbols to represent this desired situation we'll call this line one and there'll be some symbols to represent the situation it starts with we'll call this line two and we'll set it the goal of making line two exactly the same as line one using these four rules that is there'll be some symbols in its memory to make two exactly the same as one that'll be its first goal now one of the nice things about a computer is it will tell you exactly what it does at every step here's a record of what gps did when it tackled this problem it's what we call the trace of the program it tells every symbol it looked at every rule that it tried and every goal that it set up of course it's all in the machine shorthand but let's see what it means the first thing the computer does is to compare line two to line one doesn't see any difficulty there there's a black block and there's no block at all so it set up a sub goal of getting rid of that difficulty that is it uses symbols to create in its memory i want to add one black flock that's goal two it then takes this description and goes through the rules looking for the one whose description is more similar and i think you can see that that's rule two here at two black blocks and so it now creates the goal of trying rule two that's its third goal and so it gets line two to be white black flat and now it's ready to start all over again and it proceeds in the same way it compares and finally finds a difficulty in which he wants to change a black into a fight and so it makes a new sub goal to get rid of that difficulty and it takes that description over to the rules to find which rule has the most similar description and that turns out to be rule four take away one black block now taking away isn't quite as close as changing as what we had before but that was sort of the best there is and that's what gps used and so we come over and take away one black block and now gps is ready to start all over again to make line two exactly the same as line one and i think you can see that it will now find this difficulty and add two white blocks and then it will see this difficulty and take one white block away and then it will see this difficulty and add two black blocks and now this difficulty and add to white block and finally this difficulty and take one white block away and so gps solved the problem that was an easy problem and gps marched right through it but it did a number of sophisticated things in building up that integrated pattern of behavior it kept goals in its memory to keep track of what it wanted it described what it had against what it wanted in order to spot the difficulty it described these difficulties and it took these descriptions to the rules to select out the right rule rather than just using any old rule now these are very human things to do which is not surprising since we built gps after describing after observing college students solve problems but perhaps they are too sophisticated to have anything to do with a small child's attempt to solve this problem after all it wasn't easy for billy but let's look and see what did happen when billy first took the problem after we had described to him how the rules worked why billy didn't even use the rules he just put the blocks down so they matched now that seems very different from gps but notice what billy's behavior does show us he compared what he had to what he wanted he spotted the difficulty he even described the the difficulty so he could find some action to take care of them in fact billy did everything just like gps except he couldn't take the rules into account billy's ability to integrate all the parts of the problem was limited at first when billy saw that adding two and taking away one went together he welded them into a unit and he always used them together even when it was inappropriate bang bang bang add to take away one he really has the idea and what did the computer do it always looked at the results of applying a rule and so it saw it didn't have to take away one black block down there at the end in fact it's as if billy was being mechanical and not the computer gps provides a tool for studying complex behaviors by formulating an information processing theory of them this theory suggests that when we solve a problem we build up an integrated pattern of behavior we build goals in our memory to keep track of what we want to do we compare where we are with where we want to go we spot the difficulties we make descriptions of these difficulties and use this to select out the right rules to apply rather than just applying any old rule the gps experiments to date have been highly encouraging the processes of thinking can no longer be considered completely mysterious in the past few years much work has been done in this new field of psychological research and much more lies ahead there are many unfinished problems nevertheless there is little doubt that the computer's ability to mirror man's mental processes and the ways that computers are used to formulate and test theories of human behavior represent one of the most exciting developments in recent psychological research [Music] [Applause] [Music] this is n e t fictional educational television