Project-Based Learning Research Review: Evidence-Based Components of Success

What boosts PBL from a fun and engaging exercise to a rigorous and powerful real-world learning experience? Researchers have identified four key components that are critical to teaching successfully with PBL (Barron & Darling-Hammond, 2008; Ertmer & Simons, 2005; Mergendoller & Thomas, 2005; Hung, 2008). All of these play a role in the curriculum-design process.

Carefully Calibrated Project Design

In general, PBL projects begin by presenting a driving question, one that focuses on intended learning objectives, aligns with students' skills, and appeals to students' interests. PBL can range from being highly structured -- to guide students toward the most efficient, optimal solution -- to having multiple or even no clear solutions (for example, a study of climate change).

If you are new to PBL, it's best to start with smaller projects that are already part of the curriculum (Ertmer & Simons, 2005). Based on an analysis of studies demonstrating successful PBL, Hung (2008) proposed a model for designing problems or projects, which focuses on content, context, calibration, researching, reasoning, and reflection, or 3C3R. According to Hung (2008), PBL is ineffective when: a) the skills needed for solving a problem are either above or below the learner's abilities, and/or b) the problem asks students to study content that is outside of the content objectives, but required for solving the problem. Teachers can avoid both common mistakes by following a seven-step procedure that sets up the problem for students (adapted from Hung, 2008).

1. Define the Content. What do you want students to learn by the end of the assignment? Expectations should correspond with students' current research and reasoning skills.
2. Identify the Context. Brainstorm a list of real-life activities in which learners could apply the intended content. Be aware of any time or location constraints in these situations.
3. List Possible Problems. Create a list of problems or projects that could occur in each context from Step Two. Select the problem or project that best presents the content objectives and that will be appealing and relevant to learners.
4. Describe Potential Solutions. Fully describe the most viable solution to the problem or project, as well as possible alternative solutions. Identify the known and unknown variables. Note the most realistic path of reasoning and the knowledge (concepts, principles, procedures, and facts) that would result from the most viable solution. Next, identify alternative paths of reasoning and knowledge that would evolve from alternative solutions to the problem. Based on these possible solutions, what researching and reasoning skills will learners need for solving the problem or creating the project? What is the best framework for building students' knowledge? (That is, how do concepts required for solving the problem relate to each other?)
5. Calibrate Your Project. Using the solutions from Step Four, check to make sure that the knowledge and skills generated by the most viable solution match the intended knowledge and skills from Step One. For instance, you might create a chart comparing the intended knowledge and skills with those necessary to solve the problem. To better match intended content with students' level, add or remove problem conditions. To make a problem easier, focus learners' attention on the target knowledge. To make a problem harder, focus learners' attention on peripheral knowledge. To make the problem more realistic, add time, budget, or location constraints that might occur in an authentic professional situation.
6. Describe the Task. To create a description of the task, remove information from the most viable problem solution from Step Four. If researching or reasoning a critical piece of information is beyond students' problem-solving skills, this information should be presented to the learners rather than have them struggle to learn it.
7. Reflect on the Learning. Reflect students' learning by including multiple opportunities to check their progress in the initial assignment and adjust instruction accordingly (for example, let them know they need to keep a journal and report to their supervisor on a weekly basis). The final assessment should also be clearly described in the assignment (for example, a final report, presentation, or follow-up question or problem) and should allow learners to reflect upon their overall learning and problem-solving process. Designing assessments is very important, and is described more fully in the assessment section.

Structured Student Collaboration

Compared to traditional instructional methods, students engaged in small-group learning achieve higher grades, retain information longer, and have reduced dropout rates, improved communication and collaboration skills, and a better understanding of professional environments (Johnson, Johnson, & Stanne, 2000; Springer, Stanne, & Donovan, 1997; Terenzini, Cabrera, Colbeck, Parente, & Bjorklund, 2001; cited in Oakley, Felder, Brent, & Elhajj, 2004). Collaborative learning promotes time on task as well as friendships across diverse groups, such as race, ethnicity, gender, or school cliques (Johnson & Johnson, 2009). Collaborative learning benefits students across grade levels, academic subjects, gender, ethnicity, and achievement level (Slavin, 1996).

To increase the success of group work, team rewards or goals should depend on growth in each individual student's skills and knowledge, with measures that account for such growth. Researchers recommend three- to four-person teams for most collaborative learning assignments (Johnson & Johnson, 2009). Lower ability students tend to work best in mixed groups, medium ability students in homogeneous groups, and for higher-ability students, group ability levels make no difference (Lou, Abrami, Spence, Poulsen, Chambers, & d'Apollonia, 1996).

Two ingredients are critical for successful collaborative learning (Slavin, 1991):

• Team goals and/or rewards based on individual learning growth. When the team goal is tied to the learning of each individual, team members care about others' learning and actively help each other. Assigning interdependent roles to students has been shown to increase students' learning and engagement through teamwork (Slavin 1996; Johnson & Johnson, 2009).
• Individual accountability. To increase group-work success, team rewards or goals should depend upon growth in each individual student's skills and knowledge. Individual learning growth must be measured in relation to each student's past performance in order to ensure that everyone has an equal chance of success. For example, teams might be awarded points based on each member's meeting or exceeding past performance, based on individual assessments.

Veteran teachers recommend tracking group progress with clear benchmarks and due-dates, meeting with groups regularly, and making evidence of group progress visible and public by using planning sheets and/or group folders (Mergendoller & Thomas, 2005). Public or classroom presentations also encourage full participation and help to promote accountability (Barron & Darling-Hammond, 2008). Group contracts also help to keep students accountable. Typically, groups collectively agree upon norms and expectations at the beginning of projects, while reflecting on the group process and product throughout (Oakley et al., 2004; Mergendoller & Thomas, 2005).

Assessments That Support Students' Success

Criteria for success on PBL tasks need to be clearly defined at the start of the project, and should include multiple opportunities for feedback, reflection, and time for students to revise their work (Barron & Darling-Hammond, 2008). At the start of a PBL assignment, teachers should provide students with clear and challenging criteria or guidelines for success, using rubrics and examples that demonstrate intended learning outcomes from local professionals or former students (Ertmer & Simons, 2005; Barron & Darling-Hammond, 2008). Students who have clear criteria for success spend more time discussing and evaluating content, and these conversations increase student learning (Cohen, Lotan, Abram, Scarloss, & Schultz, 2002; cited in Barron & Darling-Hammond, 2008).

Inquiry-based learning is most productive when teachers provide students with frequent assessments and redirection through project benchmarks and reflection activities (Barron & Darling-Hammond, 2008). Providing students with feedback that they act upon produces significant learning gains (Black & William, 1998a; Hattie, 2008). Frequent feedback enables teachers to adapt their instruction to target students' learning needs, while providing students with information to develop their work. What's more, by emphasizing the process, effort, and strategies involved in accomplishing a task -- as opposed to focusing solely on the final product -- students come to understand that learning is the result of cumulative effort. This, in turn, improves their resilience and academic achievement (Dweck, 2000).

Barron and Darling-Hammond (2008) recommend providing students with several opportunities to review and revise their project work (as a way of delivering a polished performance) and providing comments rather than grades during these assessments to focus attention on the quality of work rather than the worker. For example, students might write a research plan, listing the questions they will need to address and sources they will read, before heading to the library or conducting an Internet search (Mergendoller & Thomas, 2005).

Researchers also recommend end goals that reflect professional practice, such as public exhibitions, portfolios, and presentations, which signal the social value and relevance of student work (Barron & Darling-Hammond, 2008). The final (summative) assessment should use many different criteria that reflect the various skills involved in the task, and these criteria should be communicated openly to students (Barron & Darling-Hammond, 2008; Thomas, 2000). To ensure that students truly understand final assessment criteria, teachers can ask students to help define the criteria (Mergendoller & Thomas, 2005).

For final (summative) assessment criteria, Hung (2008) recommends these six items:

1. necessary knowledge acquisition (for example, "need to knows," or content objectives)
2. depth of study
3. effectiveness and efficiency of research methods
4. logical and effective reasoning
5. conceptual integration of knowledge
6. effective problem-solving strategies

Barron and Darling-Hammond (2008) recommend assessing these six items:

1. use of evidence
2. accuracy of information
3. evaluation of competing views
4. development of a clear argument
5. attention to writing conventions
6. collaboration

A Supportive Network for Teachers' Professional Development

It should be noted that "the curriculum approach by itself cannot do it all," (Kolodner, Camp, Crismond, Fasse, Gray, Holbrook, Puntambekar, & Ryan, 2003, p. 542). The success of PBL also depends on motivating and supporting teachers in new roles of facilitating inquiry. Teachers learn PBL by collaborating with colleagues, introducing PBL in the classroom, and reflecting on their experiences (Krajcik, Blumenfeld, Marx & Soloway, 1994).

A number of online networks support teachers as they collaboratively develop their expertise in PBL methods. For example, PBL teachers share project ideas, receive feedback, and interact with other PBL classrooms using the Buck Institute for Education's (BIE) Project-Based Learning network on Edmodo. BIE also offers a wealth of free project-based-learning resources and online professional-development courses in PBL.

Providing teachers with professional development courses in inquiry-based teaching methods is critical for achieving positive PBL results on a district-wide scale (e.g., Geier, Blumenfeld, Marx, Krajcik, Fishman, Soloway, & Clay-Chambers, 2008; Finkelstein, Hanson, Huang, Hirschman, & Huang, 2010). For more information on effective professional development practices, see Edutopia's Professional Learning page.

Although the transition to teaching with project-based learning can be challenging and time consuming, several studies show that teachers ultimately find the PBL approach to be more rewarding and enjoyable than traditional teaching methods (Strobel & van Barneveld, 2009). Longitudinal research also indicates that when teachers create the interactive and engaging classroom environments typical of inquiry-based learning, students are more successful over the long term (Darling-Hammond, 1996; Zimmerman, 2002).

Continue to the next section of the PBL research review, Best Practices Across Disciplines.