Tower Of Straws: Reaching New Heights With Active Learning In Engineering Design For The First Year Curriculum

Building a tower out of straws has been used as an activity for many years at all educational levels. In general terms, teams of students are provided with a fixed number of straws and fasteners (such as paper clips or straight pins) and are instructed to build a structure as tall as possible within a limited amount of time. Sometimes a constraint is added, usually that the tower must be able to bear a specified load or withstand other mechanical disturbances such as wind or vibration. Lesson plans for this activity are readily available on the Internet; the majority of them present the building of a tower of straws by a team of students as a methodology for developing cooperative learning skills. However, it is possible to modify this activity for use in first-year college engineering courses as an introduction to, or illustration of, the engineering design method. The scope of the problem is well-defined, allowing for the entire engineering design process to be accomplished within a short period of time. First, the problem is given to the class with appropriate constraints. Teams are formed to design and analyze possible solutions, which may include the development of drawings and/or prototypes. From the suggested solution alternatives, decision matrices are developed through classroom exercises for evaluating the success of the design against the set of original performance criteria determined by the students at the outset. Tasks are assigned amongst the team members, delegating roles for planning, design, and assembly of the structure. A testing protocol is developed and utilized following the building of the towers in class. Finally, reflection is used to help summarize the learning experiences in the areas of engineering design and teamwork, and how they can be applied in the future. The purpose of this paper is to examine the methodologies successfully used at two institutions for implementing the Tower of Straws assignment and provides an assessment of its usefulness as an active learning exercise in introducing first-year engineering students to the engineering design process. The paper will describe two very different approaches to the same exercise, along with the assessment results from both Ohio Northern University (ONU) and Northeastern University (NU). The assessment tool maps responses to what the students perceive they learn about the design process steps and also assesses if the students learn engineering principles and teamwork the way the instructors intend for them. Suggestions for expanding on or modifying the activity for the purposes of engineering education and practical application will also be presented and all materials for implementing the Tower of Straws will be made available to educators in the appendices. 1. Background on the Tower of Straws Assignment The Tower of Straws assignment has had a history of use in K-12 education. There are a variety of names offered to the exercise, as well as different sets of goals to be accomplished. Appendix A offers a sampling of 12 online resources related to this assignment. An analysis of data culled from these sites offers some insight as to the general characteristics of the typical Tower of Straws assignment. Obviously, all include straws as the primary construction material; however, the number of straws varies from a low of just 16 to a high of 200, with 50 being the most P ge 12497.2 common value. Additionally, while most implementations prohibited cutting straws, several allowed scissors as a tool. The materials used for connectors varied between paper clips, straight pins, and modeling clay. The basic constraints involved having a limited amount of time for construction utilizing only the provided materials. All examples indicated that this activity could be accomplished within a single class session. The predominant construction goal was to build the tallest tower; however, some versions of the assignment required being able to support a load: items specified included a tennis ball, a block of wood, and even two dictionaries. A couple of the assignments indicated as a criterion the ability to support the greatest amount of load. One assignment, which uses the Leaning Tower of Pisa as its inspiration, also included the ability for the tower to lean without falling as a criterion. The predominant teaching goals are teamwork and problem solving, with the physics behind such structures being implicitly involved in most cases and explicitly examined in a couple. Recommended group sizes ranged anywhere from two to five students, with ages ranging from elementary through high school. Many of our students have had prior experience with a tower construction project and with construction projects in general during their K-12 experiences. A survey of the freshman engineering students at Ohio Northern University indicated that 24% had had some experience with a tower building assignment, and 50% indicated that they had had prior experience with construction-type assignments, primarily building either towers or bridges. One item that the authors were unable to find during their background research was any assessment data pertaining to the effectiveness of any version of the Tower of Straws assignment. Consequently, one of the goals of this research is to gather this information from conducting two versions of this assignment at our respective institutions and to report upon the evaluation of the results in this paper. 2. Institutional Background In order to understand the adaptations made by each institution to the Tower of Straws assignment, it is important to know something of the courses involved, including their goals and the particular engineering design methodology utilized. 2.1 Northeastern University. The College of Engineering at Northeastern University offers a first-year Engineering Design course during the entering semester. The course has similar goals and objectives to Engineering Design courses offered by other educational institutions, in that it promulgates teaching the principles of engineering through “hands-on” tasks for students in areas such as creativity stimulation, construction work, and associated reporting in relation to projects the students produce in teams. The philosophy of the Engineering Program is reflected in the students’ first course in Engineering Design: Promote and deliver practical, memorable, applied education with requirements for technical knowledge, opportunities for innovation, and the prospect for recognition. At Northeastern University, the students’ introduction to the phases of the engineering design process is initially set out for them by use of the principles as espoused by Voland in his book “Engineering by Design” 1 . The students are exposed to two substantial design projects and a variety of smaller assignments. The projects follow the stages of engineering design process and are aligned with Voland’s outline in the first chapter of his book. Specifically, Voland identifies P ge 12497.3 the following five primary tasks or phases and one contemplative stage of the engineering design process: 1. Needs assessment, 2. Problem formulation, 3. Abstraction and synthesis, 4. Analysis (of alternatives), 5. Implementation, and 6. Reflection and iteration. The first design project, called the Minor Project, is typically a building project that exposes the students to the design process and gives them a chance to foster creativity. The second “Major” design project does not require the creation of a working prototype and therefore is more focused on assessing the student’s ability to analyze and apply all phases of the design process to a particular topic in greater detail and over a more extended time period than the first project. 2.2 Ohio Northern University. The College of Engineering at Ohio Northern University requires all freshmen in their first quarter to take Freshman Engineering 1, which introduces the students to the engineering profession and application of the engineering method. This includes identification and definition of problems, consideration of assumptions and constraints, generation of problem solutions through the application of standard engineering techniques, and communication of results through standard reporting formats. Part of the goals for this course is that students effectively work in teams to accomplish the tasks, use the engineering method to generate solutions to analysis and design problems, and develop technical documents typical of engineering practice. To this end, two books are used in this course: “Introduction to Engineering Design and Problem Solving,” by Eide et. al., 2 provides the engineering component whereas Beer and McMurray’s “A Guide to Writing as an Engineer” 3 provides the technical writing component. Students are presented with both independent and team-oriented assignments during the quarter, including a minimum of two “hands-on” engineering design problems assigned to teams of three to five students. Chapter 2 of the Eide book presents engineering design as a 10-step process: 1. Identification of a need, 2. Problem definition, 3. Search for information, 4. Constraints, 5. Design criteria, 6. Alternative solutions, 7. Analysis, 8. Decision, 9. Specification, and 10. Communication. 3. Tower of Straws Assignment Adaptations for Teaching Engineering Design This section describes the approaches adopted by each of the participating universities for implementing the Tower of Straws activity. While there are many similarities, the differences P ge 12497.4 highlight opportunities to emphasize varying elements of engineering design. This section also presents the specific activities used at the two institutions during their respective fall terms in 2006 as arranged for this collaboration. 3.1 Northeastern University. At NU, the Tower of Straws activity is accomplished in one day as an in-class activity. It also serves as a teamand morale-building exerci