1. Teaching Assistants Facilitating Conceptual Understanding in an Introductory Chemistry Laboratory Course Using the Science Writing Heuristic: Quantitative and Qualitative Aspects Sozan Omar 1, Brian Hand 2 & Thomas Greenbowe 3 Curriculum & Instruction 1,2 and Department of Chemistry 3 Iowa State University Ames, IA 50010 Abstract Implementation of the science writing heuristic (SWH) has proven to facilitate better conceptual understanding from laboratory activities. However, the implementation requires changes to the instruction compared to the pedagogy used with traditional laboratory activities. In this study, the researchers focus on the teacher effect in promoting conceptual understanding when implementing the SWH. Students ’ scores on the practical examination and observations of four teaching assistants involved in the SWH laboratory sections were collected. Results showed a positive relationship between the implementation of the teacher ’ s template and student performance. Students in the laboratory section, where the teaching assistant implemented teaching strategies as defined by the SWH, obtained significant higher laboratory examination scores than students in laboratory sections where the teaching assistants did not properly implement the SWH. Introduction In developing the SWH, Hand and Keys (1999) constructed a template for both, teachers and students. The student template is centered on structuring the learning from the outcomes from the laboratory activities, while the teacher template focuses on the necessary pedagogy to support learning. Using the SWH provides opportunity for the students to think, negotiate ideas with peers and teacher, link claims to evidence, and reflect upon their learning through writing the laboratory report. However, using the SWH requires change to the pedagogy used by teachers for traditional laboratory activities. Teachers need to adopt more student-centered approaches so as to encourage students to take more control over their learning and facilitate their inquiries and negotiations. If the SWH were not viewed as the implication of both templates, then the student template component would merely represent a different writing format for a laboratory report and thus lose its significant meaning. The Science Writing Heuristic (SWH) Templates Teacher ’ s template Exploration of pre-instruction understanding Pre-laboratory activities Laboratory activity Negotiation- individual writing Negotiation- group discussion Negotiation- textbook and other resources Negotiation- individual writing Exploration of post-instruction understanding Student ’ s template Beginning questions or ideas What are my questions about this experiment? Tests and Procedures What will I do to help answer my questions? Observations What did I see when I completed my tests and procedure? Claims What can I claim? Evidence What evidence do I have to support my claim? How do I know? Why am I making these claims? Reading How do my ideas compare with others? Reflection How have my ideas changed Comparison and Contrast for the SWH Format vs. the Standard Format Research Questions Do students who use the SWH demonstrate better understanding than students using traditional laboratory approach in freshman chemistry laboratory classes? Does the pedagogical implementation affect student performance when using the SWH? Research Methodology Content Lecture Stoichiometry calculations including calculations of aqueous reactions and thermochemistry Laboratory Preparation of a salt, empirical formula of some simple compound, acids bases and their reactions, calorimetry, and applying Hess’s Law Teaching Assistants Jeffery* SWH 19 Students Standard 14 Students Linda* Standard 17 Students SWH 18 Students Bob* SWH 19 Students Standard 18 Students Danny* SWH 17 Students * All names are pseudonyms Quantitative Analysis Prior to the study Analysis of Variance for the ACS California Diagnostic Exam Scores with groups (SWH and standard) as independent variable After The Study A 2x4 Analysis of Covariance for the laboratory mid- exam scores with both groups and TAs as independent variables and the ACS California Diagnostic Exam as a covariate Qualitative analysis Observations Observations of TA’s performance in four laboratory SWH periods For each observation, the types of interactions promoted were classified and coded. Coding One-way interaction from: - TA to students in large group: LG (TA  Std) in small group: SG (TA  Std) - students to TA in large group: LG (Std  TA ) in small group: SG (Std  TA) - student to student in small group: SG (Std  Std) Two-way interaction between: - TA and students in large group: LG (TA  Std) in small group: SG (TA  Std) - Student and student in large group: LG (Std  Std) in small group: SG (Std  Std) Codes & Examples for All Types of Classified Interactions SG (Std  Std): Discussion of the beginning questions SG (Std  Std): Providing calculation for the results SG (TA  Std): Answering a question with a question SG (TA  Std): Answering student’s questions SG (Std  TA): Checking student’s beginning questions LG (TA  Std): Discussion of claims & evidences LG (Std  TA): Sharing the beginning questions LG (TA  Std): Modeling inquiry beginning questions LG (Std  Std): More control of the activity Quantitative Results Prior to The Study The result of the ANOVA for participants ’ ACS California Chemistry Diagnostic Exam with groups as the independent variable was not significant, F (1,125) = 0.288, p<0.592, η 2 = 0.002 After The Study The results of 2x4 ANCOVA analysis: was not significant for the groups F (1,114) = 2.624, p<0.108, η 2 = 0.023, was significant for the TAs effect F (3,114) = 11.88, p<0.000, η 2 = 0.238 TAs Effect TAs Groups Differences * Prior to the StudyAfter the Study Jeffery t (0.0167, 31) = 1.31 p<0.201 t (0.0167, 31) = 3.42 p<0.002 Linda t (0.0167, 33) = - 0.97 p<0.34 t (0.0167, 33) = -1.15 p<0.26 Bob t (0.0167, 35) = 0.25 p<0.80 t (0.0167, 35) = 0.12 p<0.91 * á = 0.017 ** Statistically Significant Qualitative Results TAs Two-way interaction TotalPercentage Total percentage Jeffery (41 Total) SG2151 83 LG1332 Linda (21 Total) SG629 48 LG419 Bob (27 Total) SG622 33 LG311 The results of this study indicate that no significant difference exist among groups (SWH and Standard); however, a significant teacher effect exists among the TAs. This suggests that the teaching strategy employed has an effect on student performance. The TA (Jeffery), whose SWH group performed significantly better than his standard group in the laboratory mid-exam, had promoted more two-way interactions (83%) compared to the other two TAs, Linda (48%) and Bob (33%). The qualitative results provide supporting evidence that to facilitate more learning from laboratory activities while using the SWH required changing to the traditional teaching strategy to adopt more student-centered through implementing more two-way interactions, whether in small or large group. Conclusion Future Work The researchers would consider the following in future work: Larger sample size for both TAs and Students Implement the study for a larger time Vary the observation periods along the study time Students’ performance in the lecture course Reference Hand, B., and C. Keys (1999). Inquiry investigation: A new approach to laboratory reports. The Science Teacher, 66, 27-29. Acknowledgement This study was funded by the National Science Foundation (NSF), project number 0088709