PBL Compare and Contrast

Mall Madness
In this problem-based learning unit, students are required to design a kid-friendly space at Northwoods Mall. From the original description of the project, it implies that they need to construct this space from the ground up, including retail space. Further reading would suggest that the space is already constructed and that students need only to design the child activity area. The authors mention in one location that it is meant for sixth- to seventh-graders. In another they state it is for seventh- to eighth- grade students.

Strengths of this unit include the use of a topic that might be of interest to the students. Student of this age range do enjoy the mall and go there for entertainment and socializing more than shopping. The unit does include the use of diverse skills such as conducting surveys, calculating a budget, and designing a space two- and three-dimensionally. Students are required to design and construct a group solution, though it is not judged based on a set of criteria aside from conforming to the survey results.

Weaknesses of this unit include a problem that is far too broad and ill defined. The space that the students are permitted to work with is not stated. The guiding questions lead students off track toward topics such as whether or not the area will be supervised or whether there will be use of contractors.  Because the feature they wish to add to the mall is to attract new mall users, it would be difficult to determine whose opinion should be surveyed. The unit requires mathematics to complete, but does not require the students to make any decisions about the mathematical methods that need to be used. I am not convinced the models constructed would confirm a student's understanding of the use of scale.

Recycling at Our School
This was a far better defined problem compared the previously described unit. While problems need not and should not be cut and dry, a problem too vague may overwhelm and therefore dilute the process with unessentials. In this unit, 5th grade students are asked to design a school recycling program. They are to develop a solution that includes the projected costs/earnings of such a program and the size and number of receptacles needed to store the recyclables. There is a potential for the solution to evolve as more information is collected. For instance, if there is earning potential, students might be encouraged to bring in recyclables from home. Students must use a number of different mathematical skills such as unit conversion and volume calculation. They also assume roles within the team to expedite the collection of information. Evaluation is based both the process and product of the unit, a written and oral presentation, and the completion of mini-lesson assignments.

A potential weakness of this problem-based unit is that there may be limited viable options available for a school recycling program in any given area. This may limit the students' ability to consider multiple potential solutions.