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.”

And,

“… 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.