In the Classroom
Student-Centered Learning: A Comparison of Two Different Methods of Instruction
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Kelli M. Slunt* and Leanna C. Giancarlo Department of Chemistry, Mary Washington College, Fredericksburg, VA 22401-5358; *
[email protected] Incorporating Student-Centered Teaching Approaches
Concept Checks
One of the recent pedagogical changes in classrooms is the use of student-centered activities (1–9). Such activities actively involve the student in the learning process rather than allow the student to passively gather information from a delivered lecture in the more traditional “sage on the stage” method of instruction. Numerous student-centered activities have been described in this and other publications (1–9). In this paper, we describe and compare the use of two studentcentered approaches, Concept Checks (2) and Just-In-Time Teaching (JiTT)(1). These methods were tested in two different small lecture classes, general chemistry and organic chemistry. This paper will briefly describe the methods, discuss their use in the classroom, and compare the effectiveness of the two strategies. At our small liberal arts institution the two-semester sequence of general chemistry (CHEM 111 and CHEM 112) and the two-semester sequence of organic chemistry (CHEM 211 and CHEM 212) are taught as multi-section courses during the academic year and single sections during the summer session. These courses have a maximum enrollment of 24 and 22 students per section, respectively. Concept Checks have been used in specific sections of general chemistry since Fall 1997 and in organic chemistry since Fall 1999. The JiTT approach was introduced in general and organic chemistry during the summer sessions of 2002.
The use of Concept Checks was adapted from an approach developed by Karen Timberlake (2) and is similar to the strategies reported elsewhere (7–8). At the conclusion of a lecture topic, one to five multiple-choice questions that focus exclusively on the concepts introduced in class are inserted into the lecture. Each question has three possible answers. After a designated amount of time, the students hold up a card(s) with the number 1, 2, or 3 to indicate their answer(s) to the question. Some of the questions require that the students hold up multiple cards. An example of Concept Checks used in general chemistry and organic chemistry is shown in Figure 1. After the instructor notes the answers, the class discusses the question. For cases in which the class is almost equally divided between two possibly correct answers, the instructor informs the students to turn to their neighbors and convince them of the correctness of his or her own choice; a re-vote is then cast. This method offers a pause in the lecture and allows the students to demonstrate comprehension of the material; if necessary, it also provides the instructor with an opportunity to re-explain difficult concepts.
Concept Check Consider the following data System E a /kJ H /kJ 1 ⴚ20 75 2 110 ⴙ50 3 ⴚ75 50 Which system has the slowest rate?
Concept Check Which of the following compounds are aromatic? 1) 2) 3)
Figure 1. Typical concept checks used in general chemistry and organic chemistry.
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Just-In-Time Teaching (JiTT) Just-In-Time teaching is a student-centered learning technique developed originally for undergraduate physics courses by Novak, Patterson, Gavrin, and Christian (1). This method uses Web-based, student-centered activities that are completed by the student prior to lecture. Some activities involve drills of previously covered lecture material while others involve warm-up or preview questions that allude to material in the next or future lectures. The approach also includes “Good-for” exercises and puzzles that demonstrate how the current concept or subject matter relates to real life. Students read essays and refer to Web pages about a topic-related news event and then complete an associated assignment. Novak et al. (1) have also developed applets that illustrate the physical concepts in a puzzle format. For the general chemistry and organic chemistry courses we have primarily adapted the Web-based drills and preview quizzes. These assignments are completed by a pre-determined time prior to the lecture, often one hour, and submitted electronically to the instructor. The instructor views the responses and tailors the lecture to the student responses (“just-in-time”). The initial portion of the lecture can usually be spent discussing any questions from the online homework and the concerns of the students. The preview material is then considered in the context of the new lecture information. During the summer sessions, the students completed JiTT assignments almost every day. During the academic year, the frequency of the assignments was once or twice a week
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for a semester-long lecture course that meets three times a week. The general chemistry students were instructed that the preview questions were meant to gauge their understanding of a major concept or topic before that material was presented in class. Students were allowed to use prior knowledge or other resources to answer the questions. A typical question and selected student responses from an early topic in the general chemistry course are provided below. • What is a “mole”? What does it represent? Why is it important? Student A: “A mole is a unit for measuring things like atoms in a molecule or compound I think… a mole deals with [Avogadro’s] number 6.02 × 1023 and that’s all I can come up with.” Student B: “A mole is amount of substance that contains as many elementary units (atoms, molecules, formula units) as there are atoms in exactly 12 g of the isotope carbon-12. A mole represents an element’s abundance considered against carbon-12. It is important because it allows us to calculate uncountable figures. A mole lets us deal with particles that are on the microscopic level.” Student C: “A unit of measure of a substance (Ex. Carbon 12 atoms) that is used in calculations. It is 6.02 × 10 to the Michael Jordan.” (Michael Jordan’s jersey number is 23.) Most of the students had an understanding of Avogadro’s number (Students A, B, and C) and the fact that this number relates to moles, but significantly fewer made the connection that a mole enables one to deal with measurable amounts rather than atoms (Student B). Other preview questions asked students to supply examples to identify understanding versus regurgitation of “book” facts. Similar questions were asked of the organic students. An example question that was posed near the beginning of the organic chemistry I course is given below with several student responses. • Covalent bonds can be cleaved homolytically or heterolytically. Explain what is meant by these terms. Student A: “In homolysis, the electrons are distributed equally in heterolysis, when the bond breaks on (sic) substance has the electrons and the other does not.” Student B: “Homolytically means that the shared electron pair is split so that one electron goes with each component. Heterolytically means that one of the components gets the entire pair of electrons and the other now will carry a positive charge.” Student C: “Homo-without breaking a certain part of the molecule? Hetero-breaks a certain part of the molecule?” Student D: “No idea, all I can picture is the old lady in three bling (sic) mice taking a wack (sic) at these poor bonds.” Most of the students (70%) had an understanding of covalent bond cleavage prior to a lecture discussion as demonstrated by the responses of students A and B. The responses by students C and D show the types of incorrect responses often provided. As with the example given from general chemistry, the students exhibited some understanding about how the bonds are cleaved but often did not include a discussion of the resulting species. The drill questions for both general and organic chemistry were taken from testbanks with only minor revisions. As noted above, the answers to these questions began each day’s lecture, and new material was only begun when the stu986
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dents had finished asking questions about the previous material. Generally, between 10 and 20 questions were assigned per topic or chapter. Assessment Methods At the conclusion of the Spring 1998 course, the general chemistry students were surveyed concerning their opinions about the use of Concept Checks. A similar survey was used to assess student opinions about JiTT at the conclusions of the Summer 2002 sessions and Fall 2002. Student performances in the courses were compared using average course GPAs and in a few cases the same examinations. Copies of selections from the surveys with results can be found in the Supplemental Material.W Student Participation In all courses, there was 98% student participation in the online drill assignments and over 95% participation with the preview questions. In contrast, 75% of the class or less were actively engaged by the Concept Checks despite repeated attempts to motivate the students to make a selection. In addition, there was less instructor confidence when the students did “vote”, since it was not obvious that they were thinking about the material rather than merely guessing. In terms of effectiveness of promoting student learning, the JiTT approach forces the student to study the material seriously. The students received credit for each correct answer in the drill exercises and for writing a response to each preview question. The responses did not need to be correct, but the students were asked to attempt to answer the questions in earnest. In order to motivate the students to put forth this sincere effort, an incentive or penalty must be associated with completion of the assignment. In the second iteration of this approach (Fall 2002), the students received credit for writing a response to the preview question and extra credit for a correct answer. The developers of JiTT also commented in their book that students are more highly motivated by items that affect their course grade (1). The Concept Checks provide a less stressful approach to assessing student understanding of concepts, since no grade is associated with the assignment. It has been observed, both in our experience and others’ (7), that students are often less likely to take the activity seriously and are frequently swayed by peer pressure (looking around at other students’ answers); thus, the “roomful” of correct answers may not truly gauge the level of student understanding. The chance to pause the lecture and move to a student-centered activity, however, does provide an often-needed change of pace that leads to an increase in the students’ retention. Student Performance Student achievement in courses utilizing JiTT was improved more than in courses utilizing concept checks or no student-centered activities. Tables 1 and 2 show class averages for grade point average (GPA) and average class exam grade on identical examinations. Due to the small sample size, a χ2 statistical analysis was not performed; these results are meant to provide qualitative evidence supporting the fact that students who have used Concept Checks and/or JiTT per-
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In the Classroom
form as well as, if not better than, students who have not been introduced to these student-centered teaching approaches. The results also reveal that the JiTT approach has a greater impact on improving student performance than the use of Concept Checks or lecture-only courses. Unfortunately, due to multiple sections of organic chemistry, only a few students who completed general chemistry utilizing only Concept Checks or using Concept Checks and JiTT enrolled in the organic chemistry course investigating the use of these student-centered activities. Of the 13 students who fall into this category, performance in organic chemistry appears to be the same. The students (10) completing general chemistry with Concept Checks only and the students (3) completing general chemistry utilizing JiTT both had an average GPA of 2.9 in organic chemistry. Benefits and Drawbacks of the Approaches Both approaches require the instructor to create a variety of questions. The Concept Check questions were included at appropriate breaks in the PowerPoint presentations used to give lectures. After the initial work of developing the questions is completed, these questions can be used with minor
Table 1. Class Grade Point Averages by Courses Using Different Student-Centered Approaches Teaching Approach for Course
Average Class GPA (1.0–4.0)
Number of Students
General chemistry course without a student-centered teaching approach
2.1
143
General chemistry courses using Concept Checks
2.1
175
General chemistry courses using Concept Checks and JiTT
2.3
135
Organic chemistry courses using Concept Checks
2.2
110
Organic chemistry courses using Concept Checks and JiTT
2.6
131
Table 2. Student Performance on Identical Examinations in Organic Chemistry Courses Using Different Student-Centered Approaches Teaching Approach for Course
Average Class Exam Grade (%)
Number of Students
Organic chemistry exam I in courses using Concept Checks
79
42
Organic chemistry exam I in courses using JiTT
86
32
Organic chemistry final exam in courses using Concept Checks
73
42
Organic chemistry final exam in courses using JiTT
73
revisions, if necessary, in future lectures. The online drills and preview questions for the JiTT approach were written and delivered to the students using classroom management software (Blackboard). The preview questions were written in a short-answer and essay format, while the drills had a variety of forms (multiple choice, fill-in-the-blank, short answer, etc.). Initially, this imposes a substantial workload on the instructor. The students complete the online activities by the assigned date and time. At the end of each quiz, students can inquire about a particular topic or inform the instructor of specific problems and areas of confusion. Students receive immediate feedback regarding their progress on the drills in that their answers are marked correct or incorrect upon submission. This provides them with an opportunity to review their work and find the error. The instructor views either individual responses or a composite analysis of the class’s answers to each question and structures the day’s lecture to include a discussion of questions most frequently missed by the class and any misconceptions that surface in the preview questions. It was enlightening as an instructor to learn about some misconceptions that might not have been uncovered except through the use of this approach. The ability to assess students’ grasp of the material several times a week rather than a few times a semester benefits both instructor and student. In addition, successful use of Concept Checks and JiTT requires that the instructor be agreeable to let the class “dictate” the lecture in the sense that topics not mastered by the majority of the students will need to be repeated and discussed in an alternate fashion. This means instructors must be willing to be flexible, addressing the needs of the students; furthermore, instructors should also hone the ability to “think on your feet”, since in both methods there is very little lead time to develop the “perfect” explanation in striving to hit upon a better means to explain a difficult concept. Student Opinions about These Teaching Approaches At the conclusion of some of the courses, the students were asked to complete an optional survey about the organization of the course and delivery of material using these approaches. The results of selected questions from the survey can be found in the Supplemental Materials.W In general, as indicated by the responses to the multiplechoice and free-response questions, the students appreciated the inclusion of Concept Checks and the JiTT approaches in their courses. In answer to the survey question “What was effective in promoting your learning in this course?” many students responded with remarks such as these: • “The online quizzes motivated me to actually look stuff up in the textbook” • “Having a quiz for each chapter was most effective. It forced me to do at least ten problems on each subject” • “The review quizzes because I couldn’t afford to slack off ” • “The quizzes were great because it gave us extra practice besides the practice problems [and] going over the quizzes in class helped” • “Having the quizzes and concept problems daily was tough at times, but made me get more involved in the material”
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• “The online quizzes also helped in understanding and keeping up with the class”
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Conclusions The success of the JiTT approach in the lower-level courses prompted instructors to use JiTT in the Biochemistry I course. Similar results of increased student performance were observed in this course as well, as indicated in Table 3. While both JiTT and Concept Checks are valuable methods for shifting the burden of responsibility onto the student for participating in his or her own education, Justin-Time Teaching is perhaps more effective in actively engaging the student. The student is responsible for reviewing previous material as well as reading ahead to prepare for the next lecture. The students realize the benefits this method: “I found that I learned more when I put more effort into completing the preview quiz because I had a better understanding when the material was discussed in class. It would have helped me more if I had completed every preview quiz as if it was a real quiz.” The use of Blackboard for course management of online material provides a means through which the student can receive instant feedback about his or her progress in the course. It also provides a non-threatening way in which students’ questions can be answered. W
Table 3. Student Performance on Identical Examinations in Biochemistry Courses Using Different Student-Centered Approaches Teaching Approach for Course
Average Class Exam Grade (%)
Number of Students
Biochemistry exam I in lecture-only course
85
18
Biochemistry exam I in courses using JiTT
89
31
Biochemistry final exam in lecture-only course
83
17
Biochemistry final exam in courses using JiTT
85
30
3. 4.
Supplemental Material
Selections from the student surveys’ results are available in this issue of JCE Online.
5.
Literature Cited
6.
1. Novak, G. M.; Patterson, E. T.; Gavrin, A. D.; Christian, W. Just-In-Time Teaching: Blending Active Learning with Web Technology; Prentice-Hall: Upper Saddle River, NJ, 1999. 2. Timberlake, K. C. In Proceedings of the 27th Conference of the International Society for Exploring Teaching Alternatives;
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7. 8. 9.
Frederickton, New Brunswick, Canada, October 1997; pp 171–172. Collard, David M.; Girardot, Steven P.; Deutsch, Howard M. J. Chem. Educ. 2002, 79, 520–523. Challen, P. R.; Brazdil, L. C. The Chemical Educator 1996, 1(5), http://chemeducator.org/tce/papers/0001005/15cha897.pdf (accessed Mar 2004). Bradley, Alexander Z.; Ulrich, Scott M.; Jones, Maitland, Jr.; Jones, Stephanie M. J. Chem. Educ. 2002, 79, 514–519. Hinde, Robert J.; Kovac, Jeffrey D. J. Chem. Educ. 2001, 78, 93–99. Wimpfheimer, Todd. J. Chem. Educ. 2002, 79, 592. Mazur, E. Peer Instruction: A User’s Manual; Prentice-Hall: Upper Saddle River, NJ, 1997. Wiediger, Susan D.; Hutchinson, John S. J. Chem. Educ. 2002, 79, 120–124.
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