2. First Implementations

3. First Iteration of Systematic Scaffolding: The Design Diaries

3. 1 The Scaffolding

Based on these findings, we developed and implemented a first approach to scaffolding for students. Scaffolding was in the form of design diaries (Puntambekar, 1997), a paper and pencil scaffolding tool. The diaries served many functions. Based on the notion that "making covert, abstract processes visible, public and manipulable, serves as a necessary catalyst for reflective metacognitive activity" (Derry, Tookey & Chiffy, 1994), the diaries served as a vehicle for providing hints. They helped students recognize what phase of designing they were in and record ideas and knowledge relevant to that phase of designing. They also provided prompts to help students decide how to move forward. They thus made thinking visible and recorded students’ journey through the design process. They contained prompts associated with each of the major stages of designing (problem understanding, information gathering, choosing a solution and evaluation), which students used as they were engaging in design activities in the classroom, and as they reflected on those activities at home in the evening. The diaries were used for an implementation of the lung problem in the same classrooms that had already done the arthropod problem. Students were required to build models to show the working of the breathing system. Models needed to show the lungs and one other part of the system.

Design diaries provided guidance for students both in carrying out design activities and reflecting on them in order to learn from them. They were used as a vehicle for providing hints, usually in the form of leading questions, as students were engaging in design activities and as they reflected on those activities at home in the evening. Diaries prompted students to make to make critical decisions, such as what function would they model, what materials they would use and why, what they needed to learn to model the function they chose, how they would evaluate potential solutions, whether they needed to revise their models, and if so, why. The main phases of the design process -- problem understanding, investigation, generating alternatives, and choosing a solution -- were supported.

Students’ responses in the design diaries showed that they required support at a more fine-grained level than we provided. While we provided support for the critical phases of the process, we provided little support for the individual activities within each phase. For example, although the diaries provided prompts to help students understand the problem better, they did not provide explicit support to help them specify the purpose of their models and come up with appropriate learning issues based on that. Further, we did not support the many activities in the solution generation phase, such as generating criteria, evaluating solutions with respect to these criteria, etc. As such students still had many difficulties with the activities within each of the design phases. We found that students on the whole were unable to specify the purpose of their designs. They concentrated on gathering interesting facts and did not focus their research on the issues that would help them design. They were not very good at generating alternative solutions. Even when they did generate solutions, because the diaries did not support generation of criteria and evaluation of their solutions, they used only pragmatic constraints (such as time, availability of materials) to judge the appropriateness of their solutions.

Based on the above findings, we designed a new set of diaries that supported not only the main phases of design, but also the activities in each phase. We also provided students with prompts to help them monitor their learning, for example, to look back at the learning issues while they did the research.

We supported four main stages of the process -- analysis or problem understanding, exploration, solution generation, and evaluation. Each stage consists of numerous activities. For example, the problem understanding phase consists of activities such as identifying the objectives, breaking the problem into subproblems, writing an initial specification and coming up with initial ideas. The exploration stage involves further understanding of the problem, narrowing down a set of issues to learn more about, literature search, refining the problem specification, establishing criteria for evaluation and other activities that help in clarifying the situation. In the third stage, that of solution generation, the knowledge for the earlier two stages is combined. It is the stage in which criteria are set, alternatives are put forth, and a solution is chosen. In the final stage, evaluation, a prototype is built and evaluated with respect to the criteria that have been generated. This is followed by identifying aspects for improvement and redesign. Table 1 shows some of the example prompts from the diaries.

These diaries were used in two situations: To support two earth science problems and two life sciences problems. The results that we are discussing in this paper are from one of the earth science problems that we supported. This problem required students to design ways to stop the erosion on Jekyll Island, one of the Barrier Islands off the coast of Georgia.

Student responses in the diaries were analyzed for the depth of their science understanding as revealed in the various design activities that they carried out. One of the most important findings was that it was not easy for students to relate their design activities to the science that they were learning. Very often their responses were too general and did not reveal an understanding of the science concepts involved. For example, in the Jekyll island problem, very few students explicitly elaborated the problem statement to indicate that the wave currents are a cause of erosion and they needed to do something about the currents. Most students only showed a shallow understanding of the problem, such as "we need to do something about people losing their properties on Jekyll". Thus they were unable to pin down the purpose that their designs had to fulfill. Many of them were more concerned about effects their designs would have on the environment than the problem of controlling erosion. Not surprisingly, their learning issues were shallow too, and they did not get to the deep science issues about long shore currents, tides, and erosion.

Table 1: Example prompts from second version of diaries

Most often, the questions that they raised dealt with issues such as "How do we build a sea wall" or "How can we stop erosion". Some of the students raised questions that made them look into the causes of erosion -- in other words, the how questions. As many of the students did not relate the problem on Jekyll to the science they were learning, their initial solution ideas were rather vague, sometimes even outrageous (e.g., put houses on stilts). However, as they progressed through the problem, some of these same students did improve their understanding of the issues concerned, beginning to mention concepts such as blocking or slowing down the current.

As their elaboration of the problem did not reflect an understanding of the science, the criteria that they used to evaluate their designs were also too broad. Very often, these related to designing and building rather than the science. For example, students came up with criteria such as ‘cost’, ‘will it last’, and ‘what will be its effect on environment’. Very few students listed criteria such ‘will it slow down the current’.

Analysis of the second version of the diaries helped us understand that we needed to provide prompts that will ‘elicit’ students’ understanding of science issues. Unless such support was provided, students did not really solve the problem with the deliberate intention of understanding the science. They simply built their models, tested them and made the statement that ‘it worked’. They are unable to justify any of their decisions in terms of the important science issues. We found that not only do students need more specific prompts during each of the design activities, the prompts need to be such that they will encourage students to explore the science.

Based on these findings, the third version of design diaries adds more support for linking design to science. Table 2 compares prompts from the second and third versions. Note that the prompts are far more specific in version three. They encourage students to reason about the purpose of their designs right from the start, thus having them think about the science issues that they should be addressing. They need to justify why the criteria that they generated are important to the solutions. Prompts are also provided to help students go back to what they have already written in the diaries, thus helping them monitor their learning. For example, they are asked to read their problem specification again before they generate criteria. In addition, we have also added examples for each of the activities in the design process.

Table 2 - prompts from version 2 and version 3 of design diaries

We analyzed student responses for the depth of science understanding. We found that in contrast to the earlier diaries (second version), students’ responses in the new version showed a greater understanding of the science issues in the Jekyll problem. Many of the students explicitly mentioned the causes of erosion right from the start of the problem. Consequently their solutions were more focused towards finding ways to slow down the long shore current and some of the other factors that are unique to the Jekyll island. Many of the students also progressed from the ‘ridiculous’ to the ‘realistic’ in their solution ideas. For example, one group of students very strongly believed that a ‘biodome’ is the only answer to the Jekyll problem. However, as they progressed through the early stages of design, the solution they came up with was to build ‘jetties’. In addition, some of the students got a more realistic appreciation of the problem in that they mentioned that they could not stop the erosion completely, but could only slow it down. Thus the prompts in the third version of the diaries were more successful in getting students to think about the science issues.