Monday, May 16, 2011

The Case against Constructivism and for Direct Instruction

In the last post we saw that Constructivism revolved around three main ideas: 1) Let children ask their own questions and construct their own solutions; 2) Provide little if any guidance and do not correct them if/when wrong; and 3) Do not teach traditional algorithms as they automatically annihilate all independent thinking.

To present the case against constructivism, I will address the first two points in this post and address the third point on traditional algorithms in a separate post.

1)     Minimal Guidance vs. Direct Instruction

In 2006, a paper written by Kirschner, Sweller, and Clark (KSC 2006) generated a swell of controversy over these very theoretical and philosophical issues. The reader is urged to read the series of papers and commentaries located at the bottom of this link Direct Instruction versus Constructivism Controversy.

The constructivist theory rests on the belief that learning and human cognition is shaped mainly through personal discovery, independent problem-solving and free thinking. Science has shown this to be true in the acquisition of “biologically primary knowledge”. For example, we learn to speak, listen, recognize faces, and interact with others very early on and mostly through immersion and experimentation in various social environments… not through constant and explicit instructions from parents/guardians/etc.

While that might be true of primary knowledge, constructivists have taken it one step further and believe the same is true for “biologically secondary knowledge” which includes most everything else.

And that’s where the rubber meets the road…

A significant body of research, including numerous controlled empirical studies, has thoroughly discredited that constructivist belief. According to KSC (2007):  

“There is no theoretical reason to suppose or empirical evidence to support the notion that constructivist teaching procedures based on the manner in which humans acquire biologically primary information will be effective in acquiring the biologically secondary information required by the citizens of an intellectually advanced society. That information requires direct, explicit instruction.”


“… we have not evolved to effortlessly acquire the biologically secondary knowledge such as the operation of a base 10 number system or scientific theories that are characteristically taught in educational institutions. That information passes through working memory and so requires conscious effort. It must be explicitly taught; indeed we invented educational institutions in order to teach such knowledge, and the manner in which it is taught needs to take into account the characteristics of working memory, long-term memory and the relations between them.”

In other words, constructivists rely on a misconception of how differing instructional and pedagogical methods interact with our current knowledge of the “human cognitive architecture”, especially in the case of young students.

2)     Cognitive Load Theory

Over the past half century, research on “cognitive load theory” has shown that we learn and recall best when our long-term memory is amply supplied with clear instructions on how to solve problems rather than when we overload our working memory by attempting to solve problems creatively without having relevant information stored in our long-term memory.

As per KSC (2006):

“Our understanding of the role of long-term memory in human cognition has altered dramatically over the last few decades… long-term memory is now viewed as the central, dominant structure of human cognition.

Working memory is the cognitive structure in which conscious processing occurs. Working memory has two well-known characteristics: when processing novel information, it is very limited in duration and in capacity.

The limitations of working memory only apply to new, yet to be learned information that has not been stored in long-term memory. In contrast, when dealing with previously learned information stored in long-term memory, these limitations disappear.”

“Solving a problem requires problem-solving search and search must occur using our limited working memory. Problem-solving search is an inefficient way of altering long-term memory because its function is to find a problem solution, not alter long-term memory. Indeed, problem-solving search can function perfectly with no learning whatsoever (Sweller, 1988). Thus, problem-solving search overburdens limited working memory and requires working memory resources to be used for activities that are unrelated to learning. As a consequence, learners can engage in problem-solving activities for extended periods and learn almost nothing (Sweller et al., 1982).”

The fact that the constructivist pedagogical methods rely almost entirely on “working memory” at the expense of “long-term memory” are (or should be) their fatal flaw.

“These memory structures and their relations have direct implications for instructional design.

Recommendations advocating minimal guidance during instruction proceed as though working memory does not exist or, if it does exist, that it has no relevant limitations when dealing with novel information, the very information of interest to constructivist teaching procedures.

Any instructional recommendation that does not or cannot specify what has been changed in long-term memory, or that does not increase the efficiency with which relevant information is stored in or retrieved from long-term memory, is likely to be ineffective.”

And after sparring with reformists (Schmidt and Hmelo-Silver) on these issues, KSC (2007) reiterates the finding that:

“After a half-century of advocacy associated with instruction using minimal guidance, it appears that there is no body of research supporting the technique. In so far as there is any evidence from controlled studies, it almost uniformly supports direct, strong instructional guidance rather than constructivist-based minimal guidance.”

Finally, and this confirms a lot of anecdotal evidence heard and read about, constructivist reform programs leave behind a lot of children that may not have “constructed” the right solution in the first place and may also reinforce mistakes made at the outset.

Again from KSC 2006:

“… Not only is unguided instruction normally less effective; there is also evidence that it may have negative results when students acquire misconceptions or incomplete or disorganized knowledge.

Note that some parents ask whether the two instructional methods can be combined to extract and deliver the best of both. When I asked Prof. R. James Milgram, Mr. Ze’ev Wurman, and other math experts that question, they all replied in the negative mainly because of the inherent pedagogical contradictions between the two methods. The post on Curricular Spiraling shows that its difficult if not impossible to combine a pedagogical method based on mastery-first with one based on incremental-learning over years. 


  1. I had commented on a prior post about the misinformation with regard to constructivism vs. direct teaching. Again, I believe there is some confusion about what constructivism really is. The last statement in this post speaks to spiraling - again not the same as constructivism. In fact, two elementary curricula use spiraling. One is "reform" (EDM) and the other is direct instruction (Saxon). Both are terrible (in my opinion). But that is because they don't apply the theory of spiraling as it is meant to be used. In fact, Bruner's theory suggests that spiraling is to be used AFTER students have mastered concepts in order to keep practicing and using what has already been learned. Constructivism does not stand in opposition to mastery or direct teaching.

  2. Sally,

    According to the article Jerome Bruner: Constructivism and Discovery Learning we are informed that Bruner “introduced the ideas of "readiness for learning" and spiral curriculum. Bruner believed that any subject could be taught at any stage of development in a way that fit the child's cognitive abilities. Spiral curriculum refers to the idea of revisiting basic ideas over and over, building upon them and elaborating to the level of full understanding and mastery.”

    Unless this quote is a misrepresentation of Bruner’s thinking, it seems clear he believes mastery is the end-result of rather than a pre-condition to the use of spiraling as you state. In that case, Mr. Bruner’s “spiral curriculum” theory would be much closer to distributed instruction than to distributed practice. Please re-read my post on Curricular Spiraling.

  3. Anyone who has read Kirschner, Sweller, and Clark's work will know that they, like you, misktakenly conflate "constructivism" with "minimal guidance" during instruction.

    In fact, they are not the same. There are a number of constructivist approaches in math and science that are well thought out and highly structured.

  4. I couldn't agree more with the whole "constructivism first, last and only" as if it is a religious teaching taught in Ed Schools and picked up by districts and even states. Projects and problems are great--so long as they provide a chance for students to "make their own" from the teachings they have been given, in one form or another. Without that, kids can do projects all through school, and only minimally make connections that are needed to use some things in a sophisticated manner.

    I am only leaving this anonymous as our area is so rigidly into constructivism, I something think it would hurt me professionally to speak up against it. There's a certain level of PC totalitarianism in some quarters....

  5. To Anonymous of Jul 22, 12:35am,

    Please elaborate on your thoughts and do provide examples/track records of Constructivist math textbooks, programs or "approaches".

  6. To Anonymous Jul 22 5:34pm,

    I am sorry to hear you feel in a "totalitarian" environment. From my own experience at school, I can tell you that you are not alone. The real question is how long will teachers and parents not say or do anything about it? Through our silence, we are sacrificing our children's education and our future.

    For some inspiration here's a quote from Bill Gates on the Constructivists' hands-off approach to learning math: "It's bullshit, if you can't do multiplication, then tell me, what is your contribution to society going to be?" (Wired: "How Khan Academy is changing the rules of education." July 15, 2011)