Marvin Minsky, March 17, 2008

Effects Of Grade-Based Segregation



Most large schools assign same-aged children into groups, where they’re all taught the same curriculum. We justify this system of “grades” by claiming that it helps to prevent inequities in size and strength, or that it promotes efficient teaching because those children will tend to have similar capabilities.  It also is argued that system helps with “socialization”—a process in which the pupils learn and share similar outlooks, opinions, and values.  Surely this process should help them to improve their mutual understanding (if only to the extent to which it gets them to think in more similar ways).


However, a different view of this suggests that age-based segregation might actually retard our children’s development:


A new class of 6-year-old children will soon begin to share similar ways to think and behave.  Then, next year, when they are 7 years old, most of those pupils will still remain in that group—and thus will tend to perpetuate those same patterns of activity. The next year, they will be 8-year-olds, but will continue to share many attitudes, values, and cognitive strategies.  So as those children proceed through their K-12 grades, large portions of their ways to think will remain much like those of 6-year-olds!


Here’s an example that shows this persistence of infantile attitudes: consider that a typical graduate of our schools can recount great numbers of anecdotes about hundreds of actors, athletes, fashion models, and other so-called ‘celebrities’—whereas very few of our modern adults can name even a single philosopher, scientist, or scholar.  Our age-based system of education does not appear to instill our kids with the qualities that we profess to admire. (Memo 3 will talk more about the importance of how children select their models and mentors).


Citizen: You seem intent to sacrifice the carefree years of childhood, and to fill them instead only with ways to advance their intellectual development.  But intelligence is not the only thing that makes our lives worth living: what about love and companionship? Surely it is important for children to have friends who share many common interests.


Of course, the classroom is not the whole of life: children can also learn from older acquaintances, including their parents, teachers, and other mentors.  And we certainly don’t want to see young minds being hurt by too much competitive anxiety.  Still, we should be concerned that excessive attachment to same-age companions could hamper a child's developing better ways to think about both social and mental activities—and I don’t know of any good evidence that age-graded classes contribute much to healthy social relationships.


As for those “carefree” aspects of childhood, we need to examine what might be involved when children engage in what we call “play.”  Adults often assume implicitly that there is a basic opposition in which Work is seen as ‘serious’ (and often coupled to discomfort and pain), whereas Play is seen as ‘frivolous’ (and mainly connected to pleasure and “fun”).   But when we look more closely at Play, we see that it often involves extreme degrees of focus, intensity, and discovery—so much that many of us might recognize, in retrospect, that never since our childhoods have we ever made ourselves Work so hard!


In any case, we all can agree that a parent who is choosing a school should try to assess its teachers and its curriculum, as well as its physical facilities.  However, it is also important to ensure that the school’s age-peer culture respects learning, discussion, and understanding, and is not dominated by terror of bullies, or contempt for the kids who the “in-groups” depict with impertinent terms like “geek,” “nerd,” or “intellectual.”

The 50-minute hour


Another problem with classroom-based schooling is that it requires a synchronized schedule: each activity must be constrained to some prearranged ‘period’ of time, after which each child is forced to switch to some different subject or topic.  This may be efficient for a management, but surely is not the most effective way to develop each child’s abilities—or those of the people who teach them.


Those time-limited periods are sometimes justified by assuming that most children have short “attention spans,” but I don’t see any sound basis for this.  Indeed when unlimited time is available, children sometimes show degrees of persistence that rival those of adult professionals—especially when pursuing what we call “hobbies.”  But when does a child get the time to pursue an idea for as long as it needs? John Taylor Gatto discusses this in Dumbing Us Down: The Hidden Curriculum of Compulsory Schooling (1992): (This was written before the advent of iPods and video games.)


“Two institutions at present control our children's lives: television and schooling, in that order. In centuries past, the time of childhood and adolescence would have been occupied in real work, real charity, real adventures, and the realistic search for mentors who might teach what you really wanted to learn. A great deal of time was spent in community pursuits, practicing affection, meeting and studying every level of the community, learning how to make a home, and dozens of other tasks necessary to becoming a whole man or woman.

“Out of the 168 hours in each week my children sleep 56. That leaves them 112 hours a week out of which to fashion a self. According to recent reports, children watch 55 hours of television a week. That then leaves them 57 hours a week in which to grow up.

“My children attend school 30 hours a week, use about 8 hours getting ready for and traveling to and from school, and spend an average of 7 hours a week in homework - a total of 45 hours. During that time they have no private time or private space [except for only] 12 hours a week.”


I suspect that there may be important variations in how people manage their “working memories.” To see what I mean, contrast these two descriptions of how a person works out an idea:


Student 1: Whenever I get a good idea, I need to work on it right away—because, if anything interrupts my thoughts, that new concept may quickly fade away.  So, most of my accomplishments have come from setting everything else aside, to work on my latest new idea for several hours immediately after conceiving it. Accordingly, when attending a lecture, I always try to sit close to an exit—so that if the speaker says something interesting, I can escape to contemplate it.  


Student 2.  I don’t much mind interruptions because I’m always multitasking anyway.  In fact, I don’t like thinking about anything for more than about a minute or two, but I don’t mind switching a lot between ideas because I don’t have trouble with getting back.


I can’t recall any research on this, but surely someone has studied it.  In any case, I have the impression that some people can develop ideas during many separate intervals—whereas others require longer, unbroken spans of time.  If so, then we need to make (and test) theories about what could account for differences in their abilities to recreate a previous mental process or state after an interruption or change of subject. 


This might also relate to the extent to which different people can take and use notes. Some teachers insist that their students take notes—and even require pupils to hand them in for grading.


Student 1. I learn a lot from taking notes, because otherwise I can’t remember much from a lecture.  However, just writing a few words from time to time is enough to help me reconstruct a lot of what was talked about.


Student 2. I can scarcely take notes at all because it is such a strain to condense what the teacher just said that I miss everything he said after that.  In fact if I keep taking notes, then later I can barely remember the lecture at all!


Here again, we see individual differences; some students can postpone reflective thinking by taking notes, but this doesn’t work well for others because their notes don’t help them enough to reconstruct the relevant mental processes.


I’m sure that children vary greatly in their abilities to recreate previous mental states, and surely this has a huge effect on how those different children learn because it will affect how they make their Credit Assignments.   I don’t have room to explain this here, so look at Section 8-5 of The Emotion Machine.  The essential point of efficient learning is that, after you have solved a problem, it is not enough just to remember the answer: you need to remember the strategies that you used to discover that answer.  Allen Newell pointed this out in his seminal paper on how to make a smart chess-playing machine.


Allen Newell 1955: "It is extremely doubtful whether there is enough information in "win, lose or draw," when referred to the whole play of the game [so, for learning to be effective], each play of the game must yield much more information. … If a goal is achieved, its subgoals are reinforced; if not they are inhibited. … Every tactic that is created provides information about the success or failure of tactic search rules; every opponent's action provides information about success or failure of likelihood inferences and so on.”


I should note that we still don’t have learning programs that work this way, perhaps because most research on learning machines has emphasized statistical inference rather than reasoning. In any case, all this suggests that clock-based classes would not be good for those who can’t tolerate interruptions.


Children have different Cognitive Styles


There is no such thing as a “typical child” because each individual person’s brain contains many different kinds of resources —and when different combinations of these are active, this can result in many different “Ways to Think.”  Thus each child develops different ways to represent various kinds of knowledge and skills—so for particular child, there will be some situations or activities at which that child might become more (or less) competent than some other children would.  But because we don’t know very much about how all those resources are organized, we tend to use vague words like “think” and  “learn” for many kinds of processes.   (See Chapters 7 and 9 of The Emotion Machine for more ideas about those processes.)  In any case, each roomful of children will contain ones who tend to learn in different ways. 


     Some children do well by beginning with abstractions and “top-down” descriptions.

     Others prefer to start with examples, and then to generalize them.

     Some do better with brief intervals of study; others do better when they can spend hours.

     Some learn best from verbal descriptions; others gain more from with graphical pictures.

     Others learn best from reading texts, while others prefer to listen to lectures.

     Yet others learn more from manual and tactile interactions with physical materials.

     Some children prosper with many easy problems; others thrive on fewer but harder ones.

     Perhaps some children learn more from success, while others learn more from their failures. I don’t know of any hard evidence for this; however among mathematicians it’s widely agreed that that one learns less from seeing examples of things than from studying counterexamples of things.


Most children have individual interests—hobbies, pastimes, and even obsessions—which may not be seen by their teachers as unrelated to the standard curriculum.  Yet each person will eventually, need to find some profession or job in society—and while most people do find useful roles, quite a few end up with nothing to do, and this can be tragic or dangerous.” This suggests that we should take care not to classify a child’s ‘peculiar special interest‘ as being an eccentricity that interferes with that child’s “normal” progression toward a “general education. Instead, in many instances, it might be better to recognize and encourage those individualistic preoccupations.  I’ll return to this in a later memo on “project-based” learning and education.” 


More generally, children develop at different rates, and each one learns in different ways—so when you put many students in the same room and try to teach the same things to all of them, some will flourish while others get stressed, and some forge ahead while others get lost.  Whatever it is that we want to teach, it is hard to design an age-based curriculum that suits the needs of pupils with different abilities.


In older times, this problem was recognized—and many pupils were “skipped” a full year or two whenever this seemed appropriate. A famous mathematician I know attributes much of his success to being skipped from Grade 3 to Grade 8.  Today this is politically unpopular, but in larger schools, “advanced placement” is still permissible—but only for a particular subject, not for an entire school year.)



It is often assumed that interacting with other children helps social development more than associating with adults.  But it might well be quite the other way around.  In any case, any method of raising children will have consequences on the children's eventual development, and this includes decisions about how we influence our children’s selections of other children or adults as friends.   For whatever one does, it will have an effect, and inaction does not avoid one’s responsibility for the outcome.  The trouble is we still know so little about how children develop that we can’t see what we are responsible for.  In particular, we need to know a great deal more about how age differences in friendship influence children's intellectual and social development—and especially about the extent to which this involves various kinds of tradeoffs. (This paragraph paraphrases some remarks by Curt Adams.)


In any case, this discussion is incomplete.  What are plausible alternatives to age-based classes?  How should such a project like OLPC relate to existing public, private and home-based schools? Where do Montessori ideas fit in? What kinds of projects are best accomplished by individuals, pairs, or larger groups?  What other issues are involved with linking younger and older pupils?   For example, how can we exploit the fact that many high-school aged “computer hackers” know more than their teachers do about computers and programming.  We still have many more questions than answers.