PROMOTING THE USE OF THE FLOW CHART IN CHEMISTRY

The student approach to the science courses at Hostos Community College shows a similar profile to what is going on nationwide. Inadequate background and lack of motivation are the most common problems found among our students, problems that make them fearful and insecure when approaching the subject matter (Zumdahl A266). These could be some of the reasons why the students do not consider science careers as professional options despite the great demand in the United States for potential scientists (AACU 9; Mervis, “NIH Told” 328; Mervis, “NIH Wants” 1119; Rochin and Mello 307). Most of the liberal arts students just take science courses because they are a requirement for earning a college degree. The hands-on experiences in these laboratory courses are scenarios where all these difficulties occur. The students do not read the experimental procedures and in some cases, even when they read them, they are not prepared to understand these procedures. In addition, the technical language of the laboratory manual makes it more complicated to comprehend the laboratory activities. All these difficulties come together at the beginning of each session. The instructor must spend too much time, about 25% of the class time, explaining the procedure and some specific techniques to be used during the laboratory session; therefore, the time to make predictions, carry out the experiments, and wrap up the procedures, which have been designed to foster the art of inquiry, problem solving and analytical skills is frequently insufficient.

Trying to overcome this problem, and to develop skills associated with the art of inquiry, analysis, reasoning, and problem solving, the flow chart methodology was introduced as a laboratory requirement at the beginning of each General Chemistry I laboratory (CHE 210 lab) in fall semester 2008. It was intended not only to help students to summarize, and understand the information, but also to minimize the laboratory procedure time. Students had to use it in order to avoid continuous book consultations and a loss of concentration and, thereby, save time. As was expected, this new “requirement” for them naturally triggered reluctance and complaints. Nevertheless, they rapidly came to understand the advantages of making the flow chart prior to their and saving time, but it was also helpful to both facilitate their understanding of the experiment and the decision-making process itself. Some students, working in pairs, immediately began to complain when their partners did not bring the flow chart because they realized that it delayed the experimental procedure. Even more surprising was the fact that by the end of the semester some students started to ask questions about the lab before they went to it, just based on the critical process triggered by the construction of the flow chart. Such questions as “Why do we have to add this reagent in this sequence?”, “Why is this color developed?”, “Why is this bubbling produced?”, “Why do we need to develop color?” became natural parts of the inquiry process. The students themselves were aware of the benefits of the flow chart because at the end of the semester they saw how it had changed their attitude towards the lab. Some of them commented that at the beginning of the semester they found the lab like “Another Chemistry lab, what a nightmare!” They also admitted that they were less afraid to make mistakes, which is an important ingredient in the learning process.

STUDENTS’ EXPERIENCES

Based on the student feedback received during the course, the students were overall very satisfied with the flow chart strategy. Most of them, about 90%, converged on the idea that the flow chart allowed them to be better prepared for the lab, to better understand the procedure, to save time in the lab, and to work more quickly and productively because it demanded that they study the experiment before they came to the lab. Others mentioned that the flow chart helped them to achieve their learning goals. Some realized the fact that the flow chart is a good solution to the experimental work because it makes it easier to undertake such experimental work without going back and forth and re-reading the long lab procedure paragraphs, a time-consuming procedure, to be sure. Eight students pointed out that the flow chart helped them not only with the chemistry lab, but also with other classes. Some of the students’ comments were:

“…the flow chart definitely helped me top work fast and clearer in the lab because it demands to study the lab before I came to the lab. Keep going with this technique…”

“...I think that the flow chart helps because in the beginning of the class I and my partner used to do bad because we were not prepared but after we started doing the flow chart we knew what we had to do and therefore were prepared for class...”

“…when the professor asked the class to do a flow chart before the class, I didn’t know how to do it. Therefore, I have learned throughout. It was extremely helpful and interesting. It has helped with other classes also…”

On the whole, students found this experience a positive one where the flow chart helped make their work more organized, easier to understand the procedure and to know what they had to do, to proceed more quickly and finish on time. Three students suggested that we include this activity as a mandatory one in the course syllabus at the beginning of the semester and acknowledge their understanding of it by giving them some credit toward the final lab grade. This way the students would likely be more motivated. Regarding this point, some of the students’ comments were:

“…I do think that the flow chart is really helpful. Keep on encouraging the students to do it and consider to ask for it as an obligation because when we talk about flow chart, we talk about a more professional way and this is college, students have to learn and practice how to be professional…”

“…. regarding the flow chart I think you should assign it as mandatory since the beginning of the semester. Students usually do not do anything if don’t have to. An advice is to give some credit for doing the flow chart, it always works…”

STUDENTS’ PROGRESS

At the beginning of the course, obviously, the students did not know how to make the flow chart, but by the middle of the course most of them, about 75% of the class, had learned how to do it. In order to quantify how well the students had learned how to prepare their experiments, during the last four labs the flow charts were collected and graded by the instructor. For the first one collected, only about 15% of the students obtained an A grade, 70% received a B grade and the remaining 15% received a C grade. By the end of the four labs collected, almost all the students obtained A and B+ grades. The most significant fact was that 90% of the students obtained an A grade in the flow chart question of the final lab exam which demonstrated that most of them had acquired the skills to prepare the flow chart and to understand the way experiments should be performed.

The flow chart technique has been extensively used by chemists, mathematics, biologists engineering in different ways. That it helped students to develop a new way of reasoning using algorithms is clear because from on-going discussions with them regarding the advantages of the flow chart procedure it was apparent that students realized how these methodological skills can be used beyond the lab duties. For example, in the last lab of the course, the efficient use of the flow chart gave time to both apply and understand a mathematical technique called Least-Square Analysis, which fits experimental outcomes to a straight line in order to find unknown quantities (Nelson and Kemp A12). Computational programs to do this analysis in order to improve these statistical experiments analysis were used as well. It was very surprising that about 60% of the class, even when it was not mandatory, prepared their lab reports by drawing on this analysis. This shows not only how the use of the flow chart and the math in the lab became more accessible to most of the students, but also how a different way of reasoning, synthesis and analysis could guide the students to build useful knowledge skills and allow them to go further in their active learning process.

In the spring 2009 term we hope to assess the use of the flow chart experience in the learning process of the General Chemistry II students (CHE 220 course). This class will be formed by students who have used the flow chart technique in CHE 210 and for those who have not used it yet. After running this experiment for two semesters, we will be able to see how these two different groups of students with dissimilar backgrounds in the use of the flow chart will develop their lab skills. We will also have a better idea about how effective the use of this technique could be in improving the performance of our students in the laboratory and in their learning process in general.

FUTURE DIRECTIONS

In the future, depending on what we learn from the experiment to be conducted in spring 2009, we are planning to include the flow chart in the syllabus as a requirement in order to encourage the students to be prepared before the lab starts. Clear rubrics will be provided for them, so they can become familiar with the flow chart preparation at the beginning of the course. We believe that this strategy, which was suggested by some students (Figure 1), will help foster students’ problem-solving skills by improving their ability to interpret scientific observations, analyze relevant aspects of the experiments they have to carry out, and delineate conclusions. A long-term goal will be to prepare a final lab exam asking the students to use the flow chart strategy by synthesizing the results of different experiments where they would have to make a hypothesis, predict and propose possible techniques in order to solve specific problems.

We think that this strategy should be able to inspire students to have scientific curiosity and give them opportunities to develop the expected hands-on and experimental design experience and the statistical and computational skills as well. It is important to point out that this flow chart initiative is just part of the current curriculum innovation and revision strategies in the chemistry courses. At present, many faculty members in the Physical Sciences Unit of the Natural Sciences Department are revisiting the teaching and learning methods in chemistry by considering our students’ weak- nesses and strengths in order to make this pedagogical process more “inviting” to the students in light of the growing demand for scientists in our world today.

Yoel Rodríguez
Natural Sciences

Nelson Nuñez-Rodríguez
Natural Sciences

WORKS CITED

Association of America Colleges and Universities (AACU) Report. College Learning for the New Global Century: A Report from the National Leadership Council for Liberal Education and America’s Promise., Washington, D.C.: Association of America Colleges and Universities, 2007. Print.

Mervis, Jeffrey. “Biomedical Training: NIH Told to Get Serious About Giving Minorities a Hand.” Science 311.5759 (2006): 328-329. Print.

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Nelson, John H. and Kenneth C. Kemp. Chemistry: The Central Science. 10th ed.

New Jersey: Prentice Hall, 2006. Print.

Rochin, Refugio I. and Stephen F. Mello. “Latinos in Science: Trends and Opportunities.” Journal of Hispanic Higher Education 6.4 (2007): 305-355. Print.

Zumdahl, Susan Arena. “Mission impossible? Improving retention of science majors among minorities and women.” Journal of Chemical Education 73.11 (1996): A266-A267. Print.