Criticisms of problem-based learning based on human cognition theory 82

In a 2006 article in Journal of Educational Psychologist, Kirschner, Sweller and Clark (Kirschner et al. 2006) make an argument against minimal guidance instruction, specifically constructivist, discovery, problem-based, experiential and inquiry-based teaching. Minimal guidance is defined within the Kirschner paper as being defined as one in which learners, rather than being presented with essential information, must discover or construct essential information for themselves. They advocate the use of direct instructional guidance which they define as “providing information that fully explains the concepts and procedures that students are required to learn as well as learning strategy support that is compatible with human cognitive architecture” (Kirschner et al. 2006 p.75). Another important aspect of their argument is that they define learning as a change in long-term memory, so clearly their theory of learning is based on behaviourism. Their argument against minimal guidance is based on human cognitive architecture and the relationship between working and long term memory. They contend that “long term memory is now viewed as the central, dominant structure of human cognition” (Kirschner et al. 2006 p.76) and learning cannot be construed to have occurred unless there has been a change in long term memory.

With regard to working memory, they make the point that working memory has two well known characteristics when it comes to functioning with novel information, that it is both limited in duration and capacity. They indicate that in minimal guided instruction, the limits of working memory are ignored with the application of problem solving, for example, which has been proven to place a large burden on working memory (Sweller 1988) and that while the working memory load is processing the problem solving, it cannot contribute to the accumulation of long term memory and hence no learning will have

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occurred. Accordingly, this has a bigger consequence for (or impact on) the novice learner as they lack the proper schemas to integrate new information with their prior knowledge.

Kirschner, Sweller and Clark do not argue against the constructivist theory. Rather, they point to a fundamental error in assuming “that the pedagogic content of the learning experience is identical to the methods and processes (i.e. the epistemology) of the discipline being studied” (Kirschner et al. 2006 p.76). Kirschner (1991, 1992) makes the same argument when he contends that the way an expert works in his or her domain (epistemology) is not always equivalent to the way one learns in that area (pedagogy). After these articles there were several articles in response to many of the points argued in Kirschner et al. (2006). In their article Schmidt (2007) point out the many structures within the design of a problem-based learning course that address the issues of the limitations of working memory:

The PBL process aims to increase the interaction between knowledge already available in the learners and the new, to-be-learned information; elaboration by (self)explanations during group discussions stimulates the integration of new information into the knowledge base already present in long-term memory (Chi, Bassok, Lewis, Reimann, and Glaser, 1989; Pressley et al. 1992)( p. 93)

They also argue that one of the main tenets of problem-based learning is that the tutors scaffold learning for student independence and that Kirschner et al. (2006) are misinterpreting the goal of student independence with novice learners being minimally guided or being unguided. Hmelo-Silver (2004 p.100) make a similar defence of problem- based learning and inquiry learning: “IL and PBL are not discovery approaches and are not instances of minimally guided instruction”. This argument is rebutted by Sweller et al. 2007 pointing out that Barrows, one of the founding fathers of problem-based learning, continues to emphasise that problem-based learning be student self-directed. This seems to be the case as previously discussed (section 3.3.2) of multiple meanings of what constitutes problem-based learning and that Swellers rebuttal is merely an argument of semantics – why does one claim the students are self directed and then argue that there is direction through scaffolding their learning? It also may be a case of multiple degrees of the meaning of self-directed. It is also worth pointing out in relation to his particular argument that

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Perry’s cognitive model (section 2.3.10) of development argues that for students to develop cognitively they must become self-directed learners.

However it is the goal of any higher education programme to produce self-directed students, however, this does not mean that the learning is self directed, merely that the approach progressively encourages the students to be more independent by providing them with appropriate opportunities to direct their own learning. Barrows may feel that his students were ready, i.e. they had already developed these self directed skills. But it is worth noting that Barrows students have already completed a primary degree. The model of problem-based learning obviously has to be adapted depending on the students’ abilities and development.

By simply giving the students a problem-based learning problem you are directing their learning, as the problem would be questioning a certain element of the course. Further scaffolding occurs through the tutors’ line of questioning, mini just in time lectures (Hmelo-Silver 2004), and the structure of the problem solving that is given by the “four columns” (section 3.3.7). All these attributes challenge the students to allocate cognitive resources that will contribute to learning. Kuhn (2007 p.718) also indicates that “the structure of problem-based instructional activities may require the most complex and demanding instructional design of all” as another indicator of the structures put in place in problem-based learning courses.

Quintana et al. (2004) conceived of scaffolding as a key element of cognitive apprenticeship, whereby students become increasingly accomplished problem-solvers given structure and guidance from mentors who scaffold students through coaching, task structuring, and hints, without explicitly giving students the final answers. An important feature of scaffolding is that it supports students’ learning of both how to do the task as well as why the task should be done that way (Hmelo-Silver, 2006). Extract from Hmelo-Silver et al. (2007 p. 100).

Another failing of problem-based learning pointed out by Sweller et al. (2007 p.117) is that “cooperation or collaboration, however, imposes costs in terms of cognitive load in that the coordination and execution of communication and interaction in groups is, in itself, often

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cognitively taxing experience”. Schmidt (2007) counter this point by asserting that it is important to train students in the instructional technique in order to reduce any additional extraneous cognitive load that engaging in problem-based learning could result in (Clark et al. 2005). Schmidt (2007 p.93) also makes the point that the structure of problem-based learning instruction is a simple to complex design: “that makes optimal use of the reduction of intrinsic load with increasing expertise, allowing students to acquire knowledge in the simpler tasks that reappear in the more complex tasks”. One of the key skills sought for a problem-based learning graduate is the ability to learn, problem solve and work in a group concurrently and that although this can be taxing cognitively that does not mean it should be ignored as a method of learning. Sweller et al. (2007 p.94) finish their defence of their original article in regards to the detriments of problem-based learning with the following statement “PBL is ineffective compared with instruction that provides direct, explicit information”. This may be the case if the sole goal of the learning environment is the transfer of information but this dramatic statement is hugely amiss in its definiteness as Schmidt (2007 p.95) ascertains “it is important to note that the goals of PBL go beyond these kind of measures” of knowledge and knowledge application and Lawton (1980 p.175) states “evaluation must be concerned with the total context of an educational situation”.

Kirschner bases this rating of ineffectiveness on the papers by Berkson (1993) and Albanese & Mitchell (1993) which will be debated later as will that of Gijbels et al. (2005 p.33) who demonstrated very recently the positive effects of problem-based learning by making the contention that “a valid assessment system would evaluate students’ problem solving competencies in an assessment environment that is congruent with the PBL environment”. Again, this is going back to constructive alignment and aligning the assessment with the learning outcomes chosen by the course designers. Gijbels et al split knowledge into three different knowledge structures that could be assessed: (a) understanding of concepts, (b) the understanding of principles that link concepts and (c) the linking of concepts and principles to conditions and procedures for application. They found that when the understanding of concepts is the subject of the assessment, students in PBL perform at least as well as students in conventional learning environments. This is in line with the conclusion of Dochy et al. (2003) that the effect of problem-based learning is more

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positive when the understanding of the principles that link concepts is at the heart of the assessment as indicated in this physics problem-based learning environment by Walsh et al. (2009).

Silen et al. (1989) puts the aim of problem-based learning as to promote learning of how to formulate problems and to find proper information, how to apply the knowledge and how to evaluate one’s own work. If Kirschner et al. (2006) do not include this as part of their evaluation of the effectiveness of problem-based learning then their contention that it is ineffective seems flawed. Sweller et al. (2007) and Kirschner et al. (2006) in their critique of problem-based learning seem to ignore some of the more positive aspects of problem- based learning such as the role that motivation plays in learning (Kuhn, 2007). As Polya (1963 p.610) puts it “for efficient learning, the learner should be interested in the material to be learnt and find pleasure in the activity of learning”. One of the prominent positive aspects of problem-based learning is that students in many research studies have reported viewing what they were learning as having increased relevance, they got greater satisfaction with their learning environment and found it to be more nurturing and enjoyable (Moore 1989; Kaufman & Mann 1996; Blumberg & Eckenfels 1988, Bligh 2000, Norman & Schmidt 2000, Albanese & Mitchell 1993, Vernon & Blake 1993, Lancaster et al. 1997, Camp 1996).

Another defence against criticisms of problem-based learning, which is based on a meta- analysis of previous work such as Berkson (1993) and Albanese & Mitchell (1993), was provide by Camp (1996 p.3) puts it “is that so many different variations of PBL exist, from very “pure” to very “impure” and each variation is called PBL for the purposes of reporting the research”. This means that both positive and negative results reported by such studies may be tainted by the inclusion of studies purporting to be problem-based learning. For example, some of the studies included could include papers that describe problem-based learning being adapted for one semester or for one subject area or in other cases it could be simply problem-based learning courses that have been implemented poorly. Another example could be a course where a tutor did not relinquish control of the learning environment to students and instead still did the majority of the talking and so was still

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trying to transmit knowledge through traditional methods. Finally, one of the most salient points in regard to rebutting the argument that “problem-based learning does not work” is to examine the absurdity of that statement. It would be the equivalent of saying “lecturing does not work”, but of course it does as long as we are clear on its purpose, and in addition the effectiveness of the lecture will also be dependent on many other things.