Why have they moved to PBL? We'll get to that later. Does PBL work? An experimental study published recently in the American Educational Research Journal suggests that it does - under the right conditions. A further intriguing aspect of the study was the authors' conclusion that collaboration is not a contributing factor to the effectiveness of PBL.
The authors define PBL as a teaching model in which students engage a problem without sufficient knowledge to solve the problem at the outset, requiring that they use prior knowledge, inquiry, and discovery to find a solution. Assessing both long-term comprehension and long-term application, the authors found that PBL facilitated statistically significant higher levels of comprehension and application than did lecture-based direct instruction. Furthermore, there was no statistically significant difference between individual PBL learners and group-based PBL learners in assessments of either comprehension or application. Both forms of PBL were superior to lecture-based instruction.
The authors, noting that most research on PBL has been done with adult learners, sought to extend research to secondary school students and conducted the current study with sixth grade urban school students from diverse socioeconomic backgrounds. While recognizing that more research is necessary in parsing the components of PBL that make it effective for secondary school students, the authors cite its potential to intrinsically motivate students by involving them in authentic, goal-based activities presented within a theme or story - this last part being particularly important for novice learners.
So just what are the right conditions for PBL to be effective?
Answering criticism that PBL is a minimally guided instructional approach that will not accommodate learners with less sophisticated prior knowledge, the authors assert that PBL is anything but minimally guided and that good PBL design includes guided instructional interventions, including limited direct instruction in which students may be presented relevant concepts and definitions. Our Texas school district friends called this the scaffolding stage, the third of a four-stage process for them that includes a social contract, the project launch, and presentation day. They described it as containing mini-lessons to help transition students from the simpler approaches to solving the problem students initially develop to more advanced analysis that incorporates relevant concepts and definitions into their determined solution paths. In the current study - which was conducted within a three-day unit - scaffolding included prompts to consider in the initial analysis stage, a condensed lecture, and a brief question-and-answer session in the middle stages of the unit.
Scaffolding, it seems to me, is a component of the process in which there is potential for wide instructional discretion in how the students' learning process is supported and advanced in PBL and depends heavily on the teacher and his or her understanding of both the instructional content and how students are likely to behave in an inquiry-based learning environment. Daniel Willingham, Professor of Psychology at the University of Virginia, writes in Why Don't Students Like School: A Cognitive Scientist Answers Questions About How the Mind Works and What it Means for the Classroom:
"Discovery learning has much to recommend it, especially when it comes to the level of student engagement. If students have a strong voice in deciding which problems they want to work on, they will likely be engaged in the problems they select, and will likely think deeply about the material, with attendant benefits. An important downside, however, is that what students will think about is less predictable. If students are left to explore ideas on their own, they may well explore mental paths that are not profitable. If memory is the residue of thought, then students will remember incorrect discoveries as much as they will remember the correct ones."
We learned from the experiences of our Texas school district friends that PBL takes tremendous planning as teachers may need to familiarize themselves with knowledge that is not necessarily directly related to a unit's standards but that can be thematically organized to ensure required standards are covered. Scaffolding processes also provide opportunities for consistent formative assessment to ensure students are exploring appropriate mental paths.
Also, I think this study underscores possible misconceptions about collaboration - mainly, that it has to be group work on a single project. The current study reveals PBL can potentially be effective in truly personalized learning environments in which consideration of the individual's learning goals is most important. The authors' finding that collaboration is not a necessary component of PBL means that the practice of collaboration can be expanded to include people outside of the classroom setting. Students could potentially be independently responsible for the advancement of an inquiry process while also relying on intermittent collaborative processes to solve a problem or complete a project.
In sharing their rationale for systematically implementing PBL into their freshman core curriculum, our Texas school district friends pointed to lagging student engagement, high failure and discipline referral rates, and low attendance. While still not quite through the first year of implementation, this school district has seen its freshman failure rate drop to its lowest level in six years, its freshman discipline referral rate cut in half from one year before, and attendance is up nearly one percentage point.
Oh.... and why are nearly 1 billion people in the world suffering from the want or scarcity of food in 2012? Not sure, but I know of some Texas teenagers who might be able to shed some light on it.
- Wirkala, C., & Kuhn, D. (2011). Problem-Based Learning in K-12 Education: Is it Effective and How Does it Achieve its Effects? American Educational Research Journal (Vol. 48, pp. 1157-1186). doi:10.3102/0002831211419491