pre-service irish science teachers' misconceptions of ...

PRE-SERVICE IRISH SCIENCE TEACHERS’ MISCONCEPTIONS OF CHEMISTRY Muireann Sheehan1,2, Peter E. Childs1, and Sarah Hayes1 1 Department of Chemical and Environmental Sciences & National Centre for Excellence in Mathematics and Science Teaching and Learning, University of Limerick 2 Irish Research Council for Science Engineering & Technology Abstract: Science teachers in Ireland are prepared through either a concurrent model or a consecutive model of teacher training. The university involved in this study offers a concurrent model of science teacher training. Like many other pre-service science teachers and students of science worldwide, these students have many misconceptions in chemistry. It has been noted that this is, in the main, due to the abstract nature of the subject which requires learners to operate at a high cognitive level. The issue of misconceptions in chemistry is a significant issue for the quality of pre-service science teachers as they may leave their third level education without having ever had their misconceptions addressed. For an improvement in science education to occur teachers must be able to apply the findings of research into chemistry misconceptions, yet many pre-service chemistry teachers have numerous misconceptions themselves. The poor subject matter knowledge of these preservice teachers is likely to lead to the transmission of misconceptions to their students. This study aims to investigate the number and type of chemistry misconceptions pre-service science teachers possess and whether these misconceptions are altered as they progress through their degree programme. Keywords: Pre-service science teachers; Chemistry misconceptions; Science education; Subject Matter Knowledge

INTRODUCTION The development of adequate subject matter knowledge (SMK) in pre-service teachers is one of the main goals of teacher education programmes. Teachers must have sufficient knowledge to be able to understand the underlying structures and organisation of a subject (Shulman 1986). Misconceptions in chemistry have been widely reported in international literature (Mulford and Robinson 2002; Tan and Taber 2009). They are known to be deeply rooted, resistant to change (Mulford and Robinson 2002) and their presence can interfere with new learning (Clement 1982). In order to address this problem, teachers must be prepared to directly address these misconceptions. Teachers’ SMK must be sufficient such that teachers have a sound understanding of the subject and hold relatively few misconceptions themselves (Shulman 1986). The pedagogical content knowledge (PCK) of science teachers must also include knowledge of common misconceptions, which they may expect to find in their students, and strategies to reduce these misconceptions (Shulman 1986).

BACKGROUND & CONTEXT Prospective science teachers in Ireland are prepared through either the concurrent or consecutive model. The concurrent model involves a four year degree programme in science, pedagogy and education. In the consecutive model, graduates of science complete a Postgraduate Diploma in Education. The university involved in this study offers a concurrent model of science teacher education. The mode of science instruction is a traditional lecture style, which has been found to emphasise lower order cognitive skills such as recall (Zoller 1993), and may result in inadequate pre-service teachers’ SMK. The SMK of teachers has been shown to have a significant effect on teachers’ ability to plan lessons, use appropriate representations and detect the misconceptions of their students. Teachers with underdeveloped SMK are more likely to include misconceptions in lesson plans and use inaccurate representations which reinforce these misconceptions (Hashweh 1987). During the spring semester 2010, the results of an exploratory study involving third year preservice teachers suggested that a number of chemistry misconceptions, particularly in the area of the particulate nature of matter (PNM), were present. A larger scale pilot study including pre-service teachers from all four years of study was then carried out. The research questions guiding this study were: 1. What chemistry misconceptions do these pre-service science teachers hold? 2. Is there a link between these misconceptions and gender, age, previous school experience of mathematics and chemistry or pre-service teachers’ chosen course of study? 3. Are the misconceptions present in the first year of pre-service teachers’ concurrent programme altered over the course of four years of formal study?

METHODOLOGY Participants in this study were required to complete a pencil-and-paper instrument designed to assess for the presence of misconceptions in chemistry. Table 1: List of Concepts & Questions included in the Instrument Concept Area

Particulate Nature of Matter

Mole Concept Chemical Bonding Equilibrium

Subtopic (where relevant) Atomic Structure Chemical Formulae & Equations Phase Change

Question No.

Concept(s) being tested

Source of Questions

Q7 Q5, Q6, Q11

Factors influencing ionisation energies Meaningful conversions from symbolic to microscopic

Taber (2003); Tan & Taber (2009) Mulford & Robinson (2002)

Q3

Understanding of phase change

Conservation

Q4

Conservation of matter

Composition of Matter

Q1, Q2

Microscopic nature matter

Q8, Q9, Q10, Q12

The mole as a counting unit, use in stoichiometry and molar volumes Process and energetics of bonding, effect of bond type and structure of ionic compounds Dynamic nature of equilibrium and the equilibrium constant

Yezierski & Birk (2006); Sheehan (2010) Mulford & Robinson (2002) Sanger (2000); Mulford & Robinson (2002) Sheehan (2010); Claesgens & Stacy (2003)

Q13, Q14, Q15, Q16, Q20 Q17, Q18

Peterson & Treagust (1989); Mulford & Robinson (2002) Krause et al. (2004); JCE website

Chemistry misconceptions and concepts related to the Leaving Certificate syllabus were identified based on the literature. The resulting instrument, described in Table 1, was composed of 23 questions and reviewed by experts. It was administered to each year group of pre-service teachers expected to receive a qualification to teach science. A response rate of 77% (212 participants) was achieved. Responses were analysed using PASW.

RESULTS The percentage of first, second, third and fourth year pre-service teachers in each grade band are shown in Figure 1. The majority of pre-service teachers (>80%) achieved less than 40%.

Figure 1: Performance of Pre-service Teachers in Instrument Table 2 shows the average score for the entire sample group of 212 for each conceptual area included on the instrument. Pre-service science teachers displayed poor understanding of all the conceptual areas in the instrument, with PNM being the most poorly understood area. Table 2: Breakdown of Mean Scores for Each Conceptual Area in Instrument Concept Area

Questions


Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q11 Q8, Q9, Q10, Q12 Q13, Q14, Q15, Q16, Q20 Q17, Q18

Stoichiometry Chemical Bonding Equilibrium All Areas

Average Score (n=212) 28.2%

% of Sample not Attempting Section 0

43.0% 32.7% 31.1% 30.8%

0.5 1.4 0.9 0

In the pre-service teachers’ responses, a number of significant factors emerged as having an effect on their performance. The year of study had no significant effect on their performance. A summary of the statistical tests performed may be found in Table 4. Figure 2 shows the performance of each year group for each question in the instrument. Nine questions were answered correctly by less 20% of the total cohort, with five questions related to PNM and two to chemical bonding. The highest number of misconceptions was in the PNM. Common misconceptions were a failure to conserve atoms (74.9%) and confusing the meaning of subscripts and coefficients (56.5%). Table 3 provides a list of the misconceptions.

Table 3: List of Specific Misconceptions found in more than 10% of Pre-service Teachers Concept Area

Subtopic (where relevant)

Misconceptions Identified


Atomic Structure

Stoichiometry

The Mole

Use of Octet Rule analogy to explain differences in ionisation energies Use of relation-based reasoning to explain differences in ionisation energies Confusing the meaning of coefficients and subscripts A failure to conserve atoms or understand the role of a limiting reagent A belief that a phase change from liquid to gas involves the breaking of covalent bonds Matter not conserved as gas weighs less or is less dense than solid Attributing macroscopic properties such as density, melting point and structure to a single atom Identifying all pure substances composed of elements as homogeneous mixtures Identifying pure substances composed of compounds as heterogeneous mixtures Identifying substances containing more than one element as compounds The mass of a particle affects the number of particles in one mole of substance The type of particles affects the number of particles in one mole of substance 12g of Carbon contains a mole of electrons Unable to apply mole ratio to generic chemical equation Belief that a solution of 1M contains molecular mass of substance in 1 L of water Belief that an ionic bond involves the sharing of electrons The electron pair is centrally located in a covalent bond Breaking bonds releases energy Ionic bonding is always stronger than covalent bonding The presence of metallic bonds raises the boiling point of a substance N2H4 is a resonance structure Lone pairs can never exist on adjacent atoms Nitrogen forms triple bonds when possible Reactant concentration increases as equilibrium is established Concentration fluctuates as equilibrium is established Failure to understanding meaning of equilibrium constant

Chemical Bonding

Equilibrium

Chemical Formulae & Equations Phase Change Conservation Composition of Matter

Volumetric Analysis

% of Sample (N=212) 42.0% 34.4% 56.5% 74.9% 30.1% 27.8% 52.4% 20.7% 25.5% 30.2% 31.1% 10.4% 58.0% 30.2% 19.8% 15.6% 30.2% 61.1% 19.3% 12.7% 15.6% 16.5% 26.9% 28.8% 20.3% 49.0%

Table 4: Significance of Relationships in the Study Relationship being Tested

Statistical Test(s)

Result

Meaning

Gender & Overall Score on CMII

Independent Samples TTest

t(210) = -4.43, p < 0.05

On average, male participants (M = 35.7, SE = 1.5) achieved higher scores than female participants (M = 28.1, SE = 0.96).

Age & Overall Score on CMII

Bivariate Correlation

r = 0.153, p < 0.05

Older pre-service teachers were found to achieve significantly higher scores.

Course of Study & Overall Score

One-Way ANOVA Hochberg Post-Hoc Test One-Way ANOVA Hochberg Post-Hoc Test Independent Samples TTest

F(5, 206)=8.29, p0.05

Leaving Certificate Chemistry Level & Overall Score Leaving Certificate Mathematics Level and Overall Score Year of Study & Overall Score

F(2, 171)=7.58, p