Downloaded via ARIZONA STATE UNIV on July 6, 2018 at 14:17:50 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.
Chapter 3
Discovering Laboratory Safety Misconceptions in Secondary Students To Promote Science Conceptual Understanding W. E. Schatzberg* Physical Science Department, Dixie State University, St. George, Utah 84770, United States *E-mail:
[email protected].
Student cognitive constructions are based on a variety of information students experience, such as media, personal experience, and previous classroom work. The student constructs experiencial information together to create theories about how the world works around them. The study of student misconceptions, ideas that differ from the commonly accepted theories that are accepted by experts in the field, can give an insight into how students are cognitively connecting ideas together and formulating educational theories that are harmful to the student and to their academic career. Researchers (Erickson, G. L. Sci. Educ. 1980, 64, 323−336; Doran, R. L. J Res. Sci. Teach. 1972, 9, 127−137) have previously showed that misconceptions students have about the world are useful to instructors and curriculum developers because the researchers can use this knowledge to construct activities to aid students developing a more reasonable understandings. Understanding how high achieving students construct concepts and what types of misconceptions are present may give new information into the role curricula plays in student learning. Singapore is consistently one of the foremost countries in student science scores and has been for many years. The goal of this research project is to discover Singaporean student misconceptions involving laboratory science theories using a Laboratory Concept Questionnaire and discover how students are forming these misconceptions.
© 2018 American Chemical Society Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
Introduction Misconceptions are student conceptions that do not correspond correctly to scientific theory. These misconceptions can hinder student learning and prevent students from achieving goals within their student career. Hammer (3) named misconception properties as: (1) having a strongly held cognitive structure, (2) differing from expert cognitive constructions, (3) affecting students’ understanding of natural phenomena, and (4) something that must be eliminated from students’ mental models (3). Many researchers have noted that the failure to address student misconceptions may be due to a mismatch between a student’s common knowledge and school knowledge (4–7). A major difference between school and a student’s home is the “heavy use of tools to solve problems in everyday settings (8).” Resnick (8) noticed that in contrasting school and home environments, abstract knowledge is favored in the school lectures while contextual knowledge is favored at home. This difference in knowledge types may provide insights into how misconceptions form and how the laboratory, where scientific theory is applied in the physical world, may be the place that misconceptions can be more readily eliminated. Abstract reasoning can be reinforced by showing students contextualized material that is akin to their home environment (9). Student conceptual understanding is defined as students having the ability to use knowledge, apply it to problems, and associate ideas to create new concepts (10, 11). Students build conceptual knowledge using newly acquired information, incorporating it into their existing mental structure, and then create a cohesive mental model in the process (12). However, students often have imprecise and incoherent knowledge before entering the classroom and any new knowledge students learn may be incorporated incorrectly into their mental model. Examples of this are seen when students use the knowledge pieces to lend support to a previous misconception, rather than incorporating the whole knowledge concept that challenges their preconception. Students may not understand the new knowledge they gained and hence the student may misinterpret the information based on previous cognitive models. Students may create piecework knowledge structures based more upon rote memorization than full conceptual understanding (13, 14). This compartmentalized information allows for only surface level understanding and does not allow the student to use and adapt the information into a functional mental model (15). Traditional teaching philosophies (14, 15) suggest that students come into the classroom first as blank slates and absorb theories only within the classroom. Recent theories about how students create misconceptions deviate from the previous teaching philosophies, suggesting that students learn by adapting previously acquired information into a cognitive web and add or remove from the web when new information is learned and applied. These learning theories would explain how students arrive at different conclusions when the students are provided the same knowledge within the science classroom. Constructivist theory states that students do not walk into a science classroom as blank slates but as those who construct new understandings based upon their prior knowledge. According to Strike and Posner (16), along with McCloskey (17), students’ 28 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
prior knowledge consists of misconceptions that are maintained due to students creating a transitional stage level of understanding. Misconceptions exist as stable knowledge in students’ conceptual understanding as a result of students fluctuating between their original conception, and the new conception they are learning (18–20). This mental construction is how students accommodate inconsistencies in their reasoning. The constructivist theory hypothesizes that conceptual change occurs when a student is confronted with evidence that contradicts the old conceptions and then the student is able to repair the misconception with scientifically accepted theory (16). This study focuses on identifying students’ misconceptions about chemistry theory and its application within the laboratory. Understanding what misconceptions students have about science theory gives an insight into how students are applying lecture concepts and provides valuable information into what experimental procedures are reinforcing misconceptions or assisting in eliminating them. Misconceptions occur when a student’s mental representation of a concept does not correspond to scientifically accepted representations; with safety considerations, these misconceptions can be dangerous to both the student and others within the laboratory classroom (2). Identification of common student misconceptions is important to determine what topics are the most difficult for students to clearly understand and to create appropriate curricula that challenges these conceptions. Misconceptions can lead to decreased academic performance and possibly create hazardous laboratory conditions. Unlike other coursework, the sciences ask the student to adapt abstract theories they learn in lecture to the practicality of the laboratory. This makes laboratory misconceptions more hazardous to students because a student mistake potentially has real world consequences beyond failing the coursework (21). Laboratory work is recognized as a place for students to acquire laboratory techniques and a place for students to apply lecture theory to real life applications. Laboratory safety is of importance because students are working around dangerous chemicals and need to know about proper handling techniques. The hazards with the laboratory are prevalent and while there is some consideration for the novice learning, such as the use of low concentration solutions, there are some chemical and physical hazards that cannot be completely avoided. Students may go through a safety talk or test at the beginning of a laboratory class, but there is the possibility that the students may not retain the information or apply pertinent chemistry theory appropriately to working in the laboratory. The science education literature contains a number of studies about students’ misconceptions regarding different areas of chemistry, but not to a large extent about misconceptions regarding laboratory concepts. Previous studies on science misconceptions have addressed specific classes such as atmospheric chemistry (21, 22) or in specific groups of people (3, 23), but it does not appear that a broad spectrum of lower level undergraduate chemistry courses have been questioned about laboratory safety conceptions. One of the most recent published research studies on the topic of laboratory safety by Churchill (24) who did a study on laboratory hazards but did not fully address students’ misconceptions about laboratory safety. This study is designed to fill in the information gap of student laboratory misconceptions and use science theory in laboratory practices. There 29 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
have been some misconception studies done previously in Asia but the subject matter has been mostly within biological field pertaining to subject-specific topics such as light and vision (25, 26). While it is important to know students’ misconceptions in biology, it would also be of importance to discover what misconceptions are occurring in the field of chemistry laboratory safety. Identifying misconceptions can give an instructor insight into what their students believe about science and provide important information into what concepts are difficult for a student to master (27). By understanding the students’ misconceptions an instructor can identify how students are creating a conceptual framework. The relevant information can be used to produce a student relevant example of how their erroneous concept does not work with an applicable real world example (28–30). The purpose of this study is to determine student laboratory misconceptions by using an open ended written questionnaire and evaluating students and instructors on a quantitative and qualitative scale. The Laboratory Concept Questionnaire was given to observe any student misconceptions and identify which misconceptions were most prevalent among the students. The Questionnaire has been previously used in research studies and evaluated qualitatively for reliability and validity on United States students in first semester general chemistry laboratory classes (31). The student and instructor answers were analyzed by key words and concepts for the given questions. The Laboratory Concept Questionnaire is composed of fourteen case study essay questions that present a situation to the student and ask them within the context of the question to define key terms, describe any emotions they felt, and elaborate on how the student would use their knowledge to handle the situation. The questions are posed as scenarios rather than single sentence questions to promote students into responding similar to how they would truly react within the laboratory. This is to promote student answers that reflect their beliefs rather than have students respond with a memorized answer. There are only fourteen questions in the questionnaire due to the nature of the questions; essay questions with students responding with in-depth high cognitive load answers. There were four types of questions, with some of the questions having more than one theme: procedural (6 questions), concepts (6 questions), terminology (3 questions), and daily life reference (2 questions).
Methods Singapore was known for its excellent with mathematics and science education (32) and the country was a mixture of eastern and western culture. The primary language in Singapore was English, which allowed qualitative interviews to be conducted without the added variable of a language translation skewing the data. Appropriate human subject paperwork was filed at both the school and country level to allow for student participation. Students in Singapore were solicited for participation and the Questionnaire was administered via computer over approximately thirty minutes. Each participating student section had their classroom instructor and a member of the research team present in the room while the Questionnaire was given. The supervision was planned to insure that 30 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
the instructor could supervise the students, handle any difficulties, and prevent students from referencing outside sources. The Questionnaires were given at end of the spring semester after the students had completed a full year of chemistry coursework. Students were chosen based on the premise that they had become familiar with chemistry concepts found in the Questionnaire and instructors had opportunities to correct any concept mistakes shown by the students. The overall participation rate was 95% of the combined enrollment from each school, with 91% from the Secondary School (72 out of 79 students) and 99% from the Junior College (72 out of 74 students). The schools were chosen based on the willingness of instructor participation. The Questionnaire was slightly adapted to the Singapore research population by soliciting expert opinions. The adapted Questionnaire had one change in wording: “fume cupboard” rather than “fume hood”. Both terms refer to the standard piece of equipment found in a general chemistry laboratory, the term is slightly different due to the difference between American and Singaporean English. The change in the Questionnaire was deemed negligible to the study analysis by experts in Singapore and the United States. The adapted Questionnaire was used in the two study classrooms and can be found in the Appendix. The Questionnaire had been previously used in research studies and evaluated qualitatively for reliability and validity with United States students in first semester general chemistry laboratory classes (31). The Questionnaire grading rubric used in this study was based on country specific answers provided by Singaporean chemistry laboratory experts and instructors. Experts, defined as those who have taught chemistry for three or more years within Singapore, were solicited to complete the laboratory safety questionnaire as a basis of comparison. Each Questionnaire question was evaluated quantitatively and qualitatively, with each question being assigned a score consisting of a numerical component and coded for key words. This study focused on identifying students’ misconceptions about chemistry theory and its application within the laboratory. The central objective of the proposed research was to understand what misconceptions about chemistry and laboratory safety were prevalent among school students regarding the chemistry laboratory. The Laboratory Concept Questionnaire was analyzed by identifying key words and concepts for the given situations posed to the students. In the Questionnaire, students were prompted to demonstrate proper usage of chemistry theory in real world applications and to create an atmosphere where students were encouraged to use informed decisions with regard to chemical hazards.
Discussion One of the goals of this questionnaire was to assess the student’s misconceptions about chemistry laboratory safety practices within a chemistry laboratory class at both the Secondary and Junior College level. Analysis was carried out by identifying evidence of key words and primary concept knowledge. The Questionnaire data was verified using student interviews and using inter-rater reliability. Reliability was confirmed via student interviews two months after the 31 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
initial interviews and comparing student responses between the interview and the Questionnaire. Reliability was confirmed if students repeated their answers they had given previously. Questionnaire validity was established in student interviews by verifying that the researcher’s interpretation of Questionnaire answers matched the student interpretation of their answers. Student interview and researcher coding agreement was seen as appropriate validity check upon the research results. The establishment of Questionnaire analysis keywords was verified using inter-rater reliability using Singapore and United States experts. The experts evaluated a small sample of student questionnaires and independently created the same keyword set in evaluating the student answers.
Question Types The concepts addressed in the Questionnaire dealt with hazard rankings of acids versus bases, mercury spill, gas leak, fume cupboard usage, strong versus weak acids, unknown chemical spill, dilution of a concentrated acid, and definitions of the terms toxic and carcinogenic (Appendix, Figure 1). Analysis of the questionnaire data shows that students appear to have some difficulties with understanding specific terminology due to previous learning outside of the laboratory classroom. This hypothesis is based on students confusing chemistry concepts on both the Questionnaires and during the interviews using information based personal experience at home and in their lives.
Real Life References Questions were asked to determine if students were relating real life experiences to the laboratory and if those real life scenarios were having an effect on laboratory procedures. Questions 5b and 7 were questions that were the most direct in asking students a question similar to something they would see in real life with the terminology carcinogenic and how to handle a gas leak. Carcinogenic is a term that was confirmed to have real world relevance by asking in student interviews if the students had seen the term outside the laboratory. The students recognized the term in the context of a warning about grilling foods and on cigarette packages. Students knew the warning in the real world, as stated in interviews they gave examples about smoking and grilling, but when questioned about what the term would mean in the laboratory context they were confused. The gas leak question was considered to have real world relevance in student interviews. The majority of secondary (71%) and junior college (75%) students answered that they would turn off the gas line themselves and in interviews were articulate that they felt comfortable handing this situation due to experience with natural gas in their own kitchens.
32 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
Figure 1. Clustering of Question Types Scientific Terminology Questions 1, 5, and 9 introduced a scientific laboratory term such as “toxic” or “carcinogenic” and asked the student in a case study what the term meant. The term ‘toxic’ (Question 1) appeared to be easily recognized by the students and understood, with majority of students associating the term with poison, dangerous, and/or harmful. Carcinogenic (Question 5) was a term that most students did not answer but still had a good population that did write that it related somehow to cancer. For question 9, strong vs. weak terminology, the common usage of the terms strong and weak in everyday language gave the students an incorrect idea about properties of acids and bases. Approximately 78% of the Junior College students and 81% of the Secondary students believed that strong acids would be more hazardous than weak acids. In student interviews, no students, when asked 33 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
to elaborate upon their choice of strong over weak, mentioned anything besides that strong meant powerful or concentrated. The student discussions of what the term ‘strong’ meant rarely mentioned the theory of hydrogen dissociation within the solution. Since the terms ‘strong’ and ‘weak’ had been discussed in lecture these results may be evidence to students not bridging between concepts learned in lecture and the application of said concepts in the laboratory. Procedural The chemistry laboratory emphasizes the learning of proper laboratory techniques and hazardous chemical handling. Questions 1, 3, 4, 5, 7, and 8 referred to these procedures to question students about these laboratory practices. These questions pertain to how to deal with chemical spills, dilution, and general chemical handling. An unexpected occurrence was seen with the evaluation of data pertaining to the question about the dilution of a concentrated acid (Question 6a). The same percentage of Junior College students (6%) and Secondary students (6%) correctly answered that acid needs to be poured into water and not water into acid. The Junior College students were expected to have a higher percentage of correct responses because they have had more laboratory experience in using these concepts than the Secondary school students. An explanation of these results could be that the upper division students became too involved with describing the equipment needed for the procedure rather than describing the theory behind the process. In student interviews, this phenomenon of over description of the equipment and under description of the chemical concepts was seen. Scientific Concepts A variety of scientific concepts were incorporated into the questionnaire to determine if students were applying lecture content to the laboratory experience. Questions 2, 3, 4, 6b, 8, and 9 discussed topics such as acid dissociation, gas theory, and neutralization. A common misconception is that acids are worse than bases (Question 2) whereas it can be either acids or bases that can cause harm. The decrease 91% Secondary students, 68% Junior College) in the percentage of students answering in this manner may be due to instructor reinforcement of alkali chemicals hazards or the introduction of new material that allowed the student to change their viewpoints. From interviews and student elaboration on the Questionnaire, the primary source of this misconception appears to be media such as books, television, movies, etc. describing acids to be extremely hazardous to someone’s health but rarely describing bases being shown as a threat or hazard.
Conclusion The analysis of what misconceptions were occurring with students is of importance from both the safety aspect and from science theory laboratory applications. Students need to be able to apply scientific theory to laboratory work and use chemistry concepts to evaluate their own safety risks. This research 34 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
study was done to identify common misconceptions and discover possible causes for students’ misconceptions. Terms such as ‘weak’ or ‘strong’ appear difficult for students to understand, possibly due the terminology denoting different phenomena in the chemistry laboratory compared to real life usage of the terms. The acid dilution concepts appears to have the same amount of students incorrectly answering the question throughout students’ academic career and perhaps instructors should devote more emphasis on safety training in regards to this topic. While acid dilution may be seen as a purely technical laboratory concept, the concept of acid and water interaction concerns both laboratory and lecture learning. Lecture and Laboratory instruction should reinforce what is occurring when acids are in water, why dilution is important and describe the physical processes. The addition of new instructional materials may give students a better understanding to why laboratory techniques are done and reinforce acid/base chemistry.
Acknowledgments The author would like to acknowledge that this project could not have been completed without the assistance of the Singapore Ministry of Education, Singapore National Institute of Education (NIE), Nanyang Technological University, and the National Science Foundation EAPSI fellowship (NSF# 1015151). Dr. Baohui Zhang of Shaanxi Normal University in Xi’an, China, was a great help to the success of this research project and assisted in the data collection. In addition, I would like to thank the experts, principals, teachers, and students at the participating schools for their cooperation and assistance.
Appendix: Laboratory Concept Questionnaire 1a. Julia who works in a chemistry laboratory and held up a chemical bottle and reads the label on it. The label reads “Toxic”. What does “Toxic” mean to you? 1b. What precaution would you suggest to her when handling the chemical? 2a. You walk into your laboratory class to do your experiment. Your lab partner has already got the chemicals, acids and bases, which you need for the experiment. Which chemical type, acids or bases, should you have more caution to work with and describe your reasoning for your answer. 2b. What chemical concepts and theories did you use in thinking about the previous question discussing the hazards of acids and bases? 3.
You and your lab partner are working on your laboratory project and your lab partner gets some chemicals to start the experiment. While getting the chemicals your lab partner accidently gets a moderate amount of 35
Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
unknown chemical on their skin, but doesn’t feel any effect from the spill. How should you and your lab partner react to the spill? 4.
Your classmates would like to know what types chemicals need to be handled in a fume cupboard/fume hood. What would you tell them?
5a. A student asks you to explain in simple terms what carcinogenic means. What would your answer be? 5b. Have you seen the term carcinogenic in a laboratory or in daily life? 6a. A student is asked to dilute a concentrated acid solution with water. Explain to the student how should they do this and provide instructions on the necessary safety precautions. 6b. What chemistry concepts and theories did you think about when you answered the last question? 7.
A student enters a vacant laboratory room and realizes that someone has forgotten to turn off the gas line used for bunsen burners and that a bunsen burner is still on. What should the student do and why?
8a. Mary accidentally broke a mercury thermometer while rinsing it in the sink after an experiment. What do you think she should she do and why? 8b. Describe your answer to the previous question. Why were the actions you described appropriate in the previous question? 9.
Mike looks at two chemicals he found in the fume hood. One is labeled as a strong acid and the other is labeled as a weak acid and both solutions have the same concentration. Which solution is more harmful and why?
References 1. 2. 3. 4. 5.
6.
Erickson, G. L. Sci. Educ. 1980, 64, 323–36. Doran, R. L. J Res. Sci. Teach. 1972, 9, 127–137. Hammer, D. Am. J. Phys. 1996, 64, 1316–1325. Allen, B. A.; Boykin, W. A. School of Psychology Review 1992, 21 (4), 586–96. Au, K.; Jordan, C. In Trueba, H. T.;Guthrie, G. P.; K. H. Au, K. H., Eds.; Culture and the Bilingual Classroom: Studies in Classroom Ethnography; Newbury House: Rowley, MA, 1981; pp 139−152. Boykin, A. W.; Toms, F . D.; Editor, H. P. McAdo0; J. L. McAdoo; Black Child Socialization: A Conceptual Framework; Sage Publications, Inc.: Thousand Oaks, CA, 1985; pp 33−51. 36 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
7.
8. 9. 10. 11.
12.
13. 14. 15. 16. 17. 18. 19. 20.
21. 22.
23. 24. 25. 26. 27. 28. 29. 30. 31. 32.
Erickson, F.; Mohatt, G., Eds.; Cultural Organization of Participation Structures in Two Classrooms of Indian Students; Holt, Rinehart, and Winston: New York, 1982; pp 132−144. Resnick, L. B. Ed. Res. 1987, 16 (9), 13–20. Johnson-Laird, P. N.; Wason, P. C., Eds.; Thinking: Readings in Cognitive Science; Cambridge University Press: Cambridge, UK, 1978. Stevens, S. Y.; Delgado, C.; Krajcik, J. S. J. Res. Sci. Teach. 2010, 47 (6), 687–715. Bransford, J. D.; Brown, A. L.; Cocking, R. R., Eds.; How People Learn: Brain, Mind, Experience and School; National Academy Press: Washington, DC, 2000. Linn, M. C.; Eylon, B.; Davis, E. A., Eds.; The Knowledge Integration Perspective on Learning; Lawrence Erlbaum Associates: Mahwah, NJ, 2004; pp 29−46. DiSessa, A. Constructivism in the Computer Age; Erlbaum: Hillsdale, NJ, 1988; pp 49–70. Griffiths, A. K.; Preston, K. R. J Res. Sci. Teach. 1992, 29 (6), 611–628. Taber, K. S. Sci. Educ. 2008, 17, 179. Strike, K. A.; Posner, G. J. A Conceptual Change View of Learning and Understanding; Academic Press: New York, 1985. McCloskey, M. Sci. Am. 1983, 249, 122. Thornton, S.; Garrett, K. J. J. Soc. Work. Ed. 1995, 31, 1. Maloney, D. P.; Siegler, R. S. Int. J. Sci. Ed. 1993, 15 (3), 283–296. Carey, S. The Origin and Evolution of Everyday Concepts. Cognitive Models of Science; University of Minneapolis Press: Minneapolis, MN, 1992; Vol. XV. Kerr, S.; Waltz, K. J. Chem. Ed. 2007, 84, 1693. Derya, K. N., D. Identification of Pre-Service Physics Teachers’ Misconceptions on Gravity Concept: A Study with a 3-Tier Misconception Test; AIP Conference, 2007. Nakiboglu, C.; Tekin, B. B. J. Chem. Ed. 2006, 83, 11. Churchill, D. G. J. Chem. Ed. 2006, 83, 1798. Toh, K.; Boo, H. K.; Woon, T. L. Res. Sci. Tech. 1999, 6, 1. Boo, H. K. Sci. Learn. Teach. 2007, 8 (1), 72007. Taber, K. S. Chemical Misconceptions; RSC Publishing; Cambridge, UK, 2002. Abraham, J.; Meir, E.; Perry, J.; Herron, J.; Maruca, S.; Stal, D. Evolution: Education and Outreach 2009, 2 (3), 393–404. Akkuş, H.; Kadayıfçı, H.; Atasoy, B.; Geban, Ö. Res. Sci.Tech. Ed. 2003, 21 (2), 54–56. Khurshid, M.; Iqbal, M. Z. Bull. Educ. Res. 2009, 31 (2), 61–74. Schatzberg, W. E.; Suits, J.; Pacheco, K. A. O.; Jones, L. J. Chem. Ed. 2018. PISA 2015 Results (Volume I): Excellence and Equity in Education; OECD Publishing: Paris, 2016.
37 Cox and Schatzberg; International Perspectives on Chemistry Education Research and Practice ACS Symposium Series; American Chemical Society: Washington, DC, 2018.
