Pre-Service Teachers’ Understanding of the Nature of Science in a Reformed, Standards-Driven Science Content Course
April Dean Adams, Northeastern State University
Monica Macklin, Northeastern State University
Pamela G. Christol, Northeastern State University
Skyleen Willingham, Mounds Public Schools
Vicky Hurst, Beggs Public Schools
Melissa Underwood, Glenpool Public Schools
Abstract
This paper documents the changes in pre-service teachers’ understanding of the nature of science after taking a reformed, standards-based science content course. The SUSSI, an instrument with both Likert items and open-ended responses was given at the beginning and again at the end of the course. Over three-quarters of the participants were white (76.1%) with the remaining participants primarily American Indian (18.7%). The pretest was used to determine initial views of the participants. The paper presents the pretest-posttest subscale differences, both Likert and open-ended responses, for which there was a significant difference in scores. The open-ended responses were used to clarify the changes in pre-service teachers’ thinking after taking the course. How this innovative course might have resulted in significant student improvement concerning some aspects of the nature of science and what changes might be necessary to additionally improve pre-service teachers’ understanding is also discussed.
Introduction
In science education, there exists the expectation of producing ‘scientifically literate’ individuals, defined as all citizens having an understanding and ability in science in order to be fully functioning citizens (American Association for the Advancement of Science (AAAS), 1989; 1993; National Research Council (NRC), 2000). One component of being scientifically literate is an understanding of the nature of science (NOS). Certain aspects of the NOS have been debated, but agreement has been reached among science educators that a set of general characteristics separates science from other disciplines. The NOS has been described as the values and assumptions inherent to the development of scientific knowledge (Lederman & Zeidler, 1987).
Teaching the NOS to improve scientific literacy has had widespread support (Hand et al., 1999) and researchers have given much consideration to assessing student understanding of the nature of science (Cleminson, 1990; Craven, et al., 2003; Lederman, 1992, 1998; Alters, 1997; Norris, 1997; Matthews, 1998). Although scientific inquiry and the NOS have been identified as essential components of scientific literacy, multiple studies of students and teachers conclude that neither group reliably demonstrates a clear understanding about the process of how science operates or the development of scientific knowledge (Aikenhead 1987; Cooley & Klopfer, 1961; Lederman, 1992; Rubba & Anderson, 1978; Abd-El-Khalick & Lederman, 2000a, 2000b). Alters (1997) and Lederman (1999) report unsuccessful attempts to address the NOS with students. Studies have further found that implicit instructional approaches that attempt to teach student understanding of the NOS through activities and project work fall short of achieving the goal at the college level (Ryder & Leach, 1999).
Matthews (1994) states that when teachers understand the NOS, they tend to make decisions that promote a deeper sense of scientific literacy. More recently, Khishfe and Lederman (2006) have shown that explicit NOS instruction can improve high school students understanding of the NOS. According to Siebert and McIntosh (2001, p. xviii), “The pre-service courses and the future teachers they serve will, in large part, determine the nation’s comfort with, knowledge about, and interest in science.” Therefore, an understanding of the development of pre-service teachers’ knowledge of the NOS is critical to teacher education programs.
Context of Study
The course investigated in this study is a science content requirement for all elementary education, early childhood education, and special education majors at a regional university in Oklahoma. The total enrollment on the university’s three campuses is approximately 9,500 students. The original campus primarily serves students from rural Oklahoma. The other campuses serve students from more urban areas. The university is a comprehensive, primarily undergraduate institution that focuses on teacher preparation. The College of Education is the largest college, and teacher preparation is an important mission of the university. Methods courses for specific content areas are taught in the content area college, not the College of Education. This practice facilitates the hiring of science education and math education faculty by the College Science and Health Professions.
Description of the Course
Entitled, Science in the Elementary School, the course is a general science content course that teaches science through inquiry. One of the major goals of the course is to help students integrate knowledge of science, learning, pedagogy and students. The course utilizes integrated hands-on inquiry, discussion, demonstration, and lecture format in which students and instructors are able to move seamlessly from one instructional format to another as needed. Whenever feasible, concepts are taught through guided inquiry using hands-on materials. Discussions and interactions with groups and individual students are used to draw attention to important aspects of the inquiry including the nature of science. Short lectures provide explanations that are not directly available through hands-on inquiry and focus on fundamental concepts. Students are given time to explore for themselves before class discussion and explanations.
The course also attempts to help pre-service teachers integrate knowledge concerning science, learning, pedagogy, and students by providing contexts in which integration may occur and providing tasks that require integration of knowledge bases. Students write a science unit plan for their choice of grades kindergarten through 8th-grade. The unit plan is aligned with state science standards and must include both science content and science process skills from the Oklahoma Priority for Academic Student Skills (PASS) (Oklahoma State Department of Education, 2002) for the appropriate grade level. These standards are in alignment with the National Science Education Standards (NSES) (NRC, 1996). The PASS standards emphasize inquiry as an appropriate means of teaching content. The common misconceptions of K-8th grade students and how to address them are also discussed in the course.
The course is guided by the following NSES professional development standards:
Professional Development Standard A: Professional development for teachers of science requires learning essential science content through the perspectives and methods of inquiry. (p. 59)
Professional Development Standard B: Professional development for teachers of science requires integrating knowledge of science, learning, pedagogy, and students; it also requires applying that knowledge to science teaching. (p. 62)
The instructor for the rural campus (First Author) taught two sections of the course in fall 2005. She holds a B.S. in Physics, an M.S. in Biology, and an Ed.D. in Curriculum and Instruction, Science Education. The instructor for one of the more urban campuses (Third Author) taught five sections of the course in fall 2005. She holds a B.S. in Elementary Education, an M.S. in Curriculum and Instruction, and a Ph.D. in Environmental Science. Both of the instructors are College of Science and Health Professions fulltime faculty. Naturally there were some differences in instruction due to the fact that there were two different instructors for the sections. However, the instructors have worked carefully to achieve course goals, and the inquiries incorporated into the course were done in all sections. Data from all seven sections were combined into one data set because it is the framework and goals of the course that we are attempting to evaluate.
The Science Teaching Efficacy Beliefs Instrument Form B (STEBI-B) (Riggs & Enochs, 1990) was administered as a pretest and posttest to 51 pre-service teachers who were enrolled in this course during the spring of 2005. The STEBI-B consists of two subscales: a Personal Science Teaching Efficacy (PSTE) Belief Scale and the Science Teaching Outcome Expectancy (STOE) Scale. An independent, two-tailed t-test was applied to the STEBI-B PSTE subscale scores and to the STEBI-B STOE subscale scores separately to determine if there was a significant difference between the means of the pre-tests and the post-tests. The comparison indicated a statistically significant improvement was found in self-efficacy, but no statistically significant change was found in outcome expectancy (Christol & Adams, 2006).
Participant Demographic Information
The participants in this study were 134 pre-service teachers enrolled in the course, Science in the Elementary School. The total enrollment in the seven sections was approximately 180. However, some students chose not to participate, and some students did not complete the pretest or posttest survey. Those students were deleted from the analysis. Table 1 summarizes the demographic information for the 134 participants. The participants were primarily women (91.8%). Over half of the students were 18-24 years of age (53.7%) and over one-third of the students were 25-40 years of age (35.1%). Over three-quarters of the students were white (76.1%) with the remaining students primarily American Indian (18.7%). The majority of the students were Elementary Education majors (67.2%) with 23.1% of the students Early Childhood majors and 5.2% Special Education majors. The Elementary Education program prepares 1st-8th grade teachers and the Early Childhood degree prepares PK-3rd-grade teachers. Most of the students (94.7%) were in their third or fourth year of college study.
Table 1
Participant Demographic Information
|
Characteristic |
Number of Participants (Percentage) |
|
Gender Women Men No Response |
123 (91.8%) 10 (7.5%) 1 (0.7%) |
|
Age 18-24 years of age 25-40 years of age Over 40 years of age No Response
|
72 (53.7%) 47 (35.1%) 14 (10.4%) 1 (0.7%) |
|
Ethnicity (Self Identified) White American Indian Asian/Pacific Islander African American Latino/Hispanic Other No Response |
102 (76.1%) 25 (18.7%) 2 (1.5%) 2 (1.5%) 1 (0.7%) 1 (0.7%) 1 (0.7%) |
|
Major Elementary Education Early Childhood Education Special Education Natural Science Secondary Science Other No Response |
90 (67.2%) 31 (23.1%)
7 (5.2%) 2 (1.5%) 1 (0.7%) 2 (1.5%) 1 (0.7%) |
|
Current Level of Study First year of college Second year of college Third year of college Fourth year of college Graduate student Other No Response |
0 (0.0%) 0 (0.0%) 46 (34.3%) 81 (60.4%) 2 (1.5%) 4 (3.0%) 1 (0.7%) |
N = 134
Methodology
Research Questions
The following research questions were investigated in this study:
Development and Validation of the Instrument
The Student Understanding of Science and Scientific Inquiry (SUSSI) questionnaire was developed over a period of three years in collaboration with an international research team that included researchers from the United States, China, and Turkey. (Liang, et al., 2005; Liang, et al., 2006). The instrument was translated into Chinese and Turkish and administered to pre-service teachers in each country. Previous students enrolled in Science in the Elementary School were participants in this project and were part of the U.S. sample. The instrument was designed to be used with large samples. It utilizes both quantitative data which can be analyzed statistically and qualitative data for each subscale. There are six subscales:
Within each subscale, there is an open-ended prompt that relates to the four Likert items in the subscale. The purpose of the open-ended item is to provide qualitative data that can be utilized to clarify student Likert responses and to provide additional details concerning student thinking. The Likert responses can be used to select students from a large sample based on their responses. The qualitative responses of these selected students can then be analyzed for patterns.
Procedure
The SUSSI was administered as a pretest and posttest during the first week and last week of class respectively. Of the students enrolled in the course on two of the three campuses, 134 students responded to all Likert items on both the pretest and posttest and were included in the study. The means on the pretest and posttest were compared with a two-tailed, paired t-test. In addition, subscale means were compared using the same method. Participants with open-ended pretest and posttest responses who also scored at least four points higher on the posttest than they did on the pretest for Subscale 3: Laws vs. Theories (N = 9) and Subscale 5: Imagination and Creativity in Scientific Investigations (N = 14) were selected for further analysis. For each of these participants’ surveys, unchanged and changed responses for each Likert item in the subscale were summarized, and unchanged and changed aspects of the associated open-ended responses were compared to the Likert analysis.
Results
Summary of Pretest Understanding of the Nature of Science
An analysis of the frequencies of pretest responses on the Likert items of the SUSSI was conducted in order to determine the initial views of this particular sample of students. Table 2 summarizes these frequencies.
1. Observations and Inferences Subscale
Most of the participants seem to have an informed view concerning the formation and interpretation of observations. Ninety-one percent of the sample agreed that prior knowledge may affect observations. Only 12.7% agreed that observations of the same event will be the same because scientists are objective, while 75.4% disagreed with the statement that observations of the same event will be the same because observations are facts and 71.6% disagreed with the statement that observations of the same event will be the same because scientists are objective. A large portion of the sample (97.8%) agreed that scientists may make different interpretations based on the same observations.
2. Nature of Scientific Theories Subscale
The participants also seem to have informed views concerning the tentativeness of theories. A large portion agreed that theories are subject to ongoing testing and revisions (94.8%), that theories may be completely replaced by new theories in the light of new evidence (89.6%), and that theories may be changed because scientists reinterpret existing observations (75.4%). However, only 66.4% disagreed with the statement that theories based on accurate experimentation will not be changed.
3. Scientific Laws vs. Theories Subscale
The results from the Likert items indicate that, like many others, these pre-service teachers agreed that scientific laws are theories that have been proven (82.8%) and that unlike theories, scientific laws are not subject to change (61.9%). In addition, many agreed that scientific theories exist in the natural world and are uncovered through scientific investigations (72.4%), while only 47.8% agreed that scientific theories explain scientific laws.
4. Social and Cultural Influence on Science Subscale
The majority of participants seemed to hold informed views on social and cultural influences on science. Most participants agreed that cultural values and expectations determine what science is conducted and accepted (56.0%) and how science is conducted and accepted (61.9%). In addition, most participants disagreed with the statements that scientific research is not influenced by society and culture (68.7%) and that all cultures conduct scientific research the same way because science is universal and independent of society and culture (78.4%).
5. Imagination and Creativity in Scientific Investigations Subscale
Many of the participants held uninformed views concerning the role of imagination and creativity in science. Less than half of the respondents agreed that scientists use their imagination and creativity when they collect data (43.3%) and when they analyze and interpret data (29.9%). In addition, less than half of the respondents disagreed with the statements that scientists do not use their imagination and creativity because these conflict with logical reasoning (36.6%) or because these conflict with objectivity (35.1%).
6. Scientific Investigation Subscale
This subscale had mixed results. Ninety percent of the respondents agreed that scientists use a variety of methods to produce fruitful results and 83.6% agreed that experiments are not the only means used in the development of scientific knowledge. However, many respondents also seemed to believe in a correct method of doing science. Only 36.6% disagreed with the statement that scientists follow the same step-by-step scientific method, and only 40.3% disagreed with the statement that when scientists use the scientific method correctly, their results are true and accurate.
In summary, according to the Likert pretest items,
· Most participants held informed views concerning observations and inferences (71.6% - 97.8%), the tentativeness of theories (66.4% - 94.8%), and the influence society and culture has on science (56.0% - 78.4%).
· Less than half of the participants had informed views on the differences between laws and theories (6.0% - 47.8%) and the importance of imagination and creativity in science (29.9% - 43.3%).
· Most participants had mixed views concerning the methods of science. Most thought that there are many ways to do science (83.6% - 90.0%), but less than half disagreed with the statements concerning a correct method in science (36.6% - 40.3%).
Table 2:
Frequencies of the Pretest Likert Responses on the SUSSI
|
Item |
Frequency of Strongly Agree and Agree (Percentage)
|
Frequency of Unsure Response (Percentage) |
Frequency of Strongly Disagree and Disagree (Percentage) |
|
1. Observations and Inferences Subscale
|
|
|
|
|
1A. Scientists’ observations of the same event may be different because scientists’ prior knowledge may affect their observations.
|
122* (91.0%)
|
2 (1.5%) |
10 (7.5%) |
|
1B. Scientists’ observations of the same event will be the same because scientists are objective.
|
17 (12.7%) |
21 (15.7%) |
96* (71.6%) |
|
1C. Scientists’ observation of the same event will be the same because observations are facts.
|
21 (15.7%) |
12 (9.0%) |
101* (75.4%) |
|
1D.Scientists may make different interpretations based on the same observations.
|
131* (97.8%) |
2 (1.5%) |
1 (0.75%) |
|
2. Nature of Scientific Theories Subscale
|
|
|
|
|
2A. Scientific theories are subject to on-going testing and revision.
|
127* (94.8%) |
6 (4.5%) |
1 (0.75%) |
|
2B. Scientific theories may be completely replaced by new theories in light of new evidence.
|
120* (89.6%) |
5 (3.7%) |
9 (6.7%) |
|
2C. Scientific theories may be changed because scientists reinterpret existing observations.
|
101* (75.4%) |
20 (14.9%) |
13 (9.7%) |
|
2D. Scientific theories based on accurate experimentation will not be changed.
|
25 (18.7%) |
20 (14.9%) |
89* (66.4%) |
|
3. Scientific Laws vs. Theories Subscale
|
|
|
|
|
3A.Scientific theories exist in the natural world and are uncovered through scientific investigations.
|
97 (72.4%) |
27 (20.1%) |
10* (7.5%) |
|
3B. Unlike theories, scientific laws are not subject to change.
|
83 (61.9%) |
30 (22.4%) |
21* (15.7%) |
|
3C. Scientific laws are theories that have been proven.
|
111 (82.8%) |
15 (11.2%) |
8* (6.0%) |
|
3D. Scientific theories explain scientific laws.
|
64* (47.8%) |
40 (29.9%) |
30 (22.4%) |
|
4. Social and Cultural Influence on Science Subscale
|
|
|
|
|
4A. Scientific research is not influenced by society and culture because scientists are trained to conduct “pure”, unbiased studies.
|
20 (14.9%) |
22 (16.4%) |
92* (68.7%) |
|
4B. Cultural values and expectations determine what science is conducted and accepted.
|
75* (56.0%) |
34 (25.4%) |
25 (18.7%) |
|
4C. Cultural values and expectations determine how science is conducted and accepted.
|
83* (61.9%) |
25 (18.7%) |
26 (19.4%) |
|
4D. All cultures conduct scientific research the same way because science is universal and independent of society and culture.
|
10 (7.5%) |
19 (14.2%) |
105* (78.4%) |
|
5. Imagination and Creativity in Scientific Investigations Subscale
|
|
|
|
|
5A. Scientists use their imagination and creativity when they collect data.
|
58* (43.3%) |
20 (14.9%) |
56 (41.8%) |
|
5B. Scientists use their imagination and creativity when they analyze and interpret data.
|
40* (29.9%) |
27 (20.1%) |
67 (50.0%) |
|
5C. Scientists do not use their imagination and creativity because these conflict with logical reasoning.
|
61 (45.5%) |
24 (17.9%) |
49* (36.6%) |
|
5D. Scientists do not use their imaginations and creativity because these interfere with objectivity.
|
63 (47.0%) |
24 (17.9%) |
47* (35.1%) |
|
6. Scientific Investigation Subscale
|
|
|
|
|
6A. Scientists use a variety of methods to produce fruitful results.
|
120* (90.0%) |
7 (5.2%) |
7 (5.2%) |
|
6B. Scientists follow the same step-by step scientific method.
|
58 (43.3%) |
27 (20.1%) |
49* (36.6%) |
|
6C. When scientists use the scientific method correctly, their results are true and accurate.
|
50 (37.3%) |
30 (22.4%) |
54* (40.3%) |
|
6D. Experiments are not he only means used in the development of scientific knowledge.
|
112* (83.6%) |
20 (14.9%) |
2 (1.5%) |
N=134
*Indicates informed response
Statistical Analysis of Pre-Test/Post-Test SUSSI Responses
Table 3 summarizes the results of the two-tailed, paired t-tests conducted on pretest-posttest total SUSSI scores and on the six SUSSI subscales. The pretest mean 81.87 (SD=7.30) and posttest mean 82.77 (SD=9.07) were not found to be statistically significantly different. Two subscales were found to have statistically significant increases in pretest and posttest means. The Scientific Laws vs. Theories Subscale pre-test mean was 9.70 (SD = 2.16) and the post-test mean was 10.17 (SD = 2.24) at p < 0.05 (t = 1.98). The Imagination and Creativity in Scientific Investigations Subscale pretest mean was 11.49 (SD = 3.67) and the posttest mean was 12.62 (SD = 4.17) at p < 0.003 (t = 3.10).
Table 3:
Results of Two-Tailed, Paired t-Tests
|
SUSSI Subscales |
Pretest Mean (SD)
|
Posttest Mean (SD)
|
t Statistic |
Significance |
|
1. Observations and Inferences Subscale
|
16.16 (2.39)
|
16.22 (2.442) |
0.2.46 |
NS |
|
2. Nature of Scientific Theories Subscale
|
15.95 (2.32) |
15.66 (2.58)
|
-1.02 |
NS |
|
3. Scientific Laws vs. Theories Subscale
|
9.70 (2.16)
|
10.17 (2.24) |
1.98 |
p < 0.05 |
|
4. Social and Cultural Influence on Science Subscale
|
14.65 (2.64) |
14.20 (3.06)
|
-1.85 |
NS |
|
5. Imagination and Creativity in Scientific Investigations Subscale
|
11.49 (3.67)
|
12.62 (4.17) |
3.10 |
p < 0.003 |
|
6. Scientific Investigation Subscale
|
13.91 (2.04)
|
13.89 (2.29) |
0.099 |
NS |
|
Total Score
|
81.87 (7.30) |
82.77 (9.07)
|
1.17 |
NS |
N = 134
Note: The higher the mean score, the more informed the response.
Comparisons of Likert Items and Open-Ended Responses for Statistically Significant Subscale Pretest-Posttest Means
Scientific Laws vs. Theories Subscale Analysis
The prompt for the open-ended response stated, “With examples, explain the difference between scientific theories and scientific laws.” Of the twenty respondents who increased their score on this section by at least four points, nine of them responded to the open-ended prompt for this subscale on both the pretest and the posttest. The open-ended responses of these students were analyzed in conjunction with their pretest and posttest Likert responses. This analysis resulted in nine individual descriptions of how students’ concepts did, or did not change after taking the course. The results are summarized in Table 4.
Table 4:
Summary of Patterns and Supporting Data for Subscale 3: Scientific Laws vs. Scientific Theories
for High-Gain Students with Pretest and Posttest Open-Ended Responses
|
Student (Points Gained on Posttest}
|
Unchanged Concepts |
Changed Concepts |
Inferences |
|
HG2 (5) |
-Theories exist in the natural world and are uncovered through scientific investigations (L).
-Laws are theories that have been proven (L&O).
-Theories explain scientific laws (L).*
-Theories are not proven (O).* |
-Laws are subject to change (L).*
|
The participant seems to have reversed hierarchy of laws and theories. Now theories are laws that have been proven. (O) In addition, the student seems to contradict themselves by stating, that laws are theories that have been proven and that laws are subject to change. Both L & O indicate confusion about the difference between laws and theories.
|
|
HG3 (5) |
-Theories exist in the natural world and are uncovered through scientific investigations (L).
-Laws are theories that have been proven (L&O).
|
-Unsure about laws being subject to change (L).
-Theories explain laws (L).* |
Although the participant states that laws are theories that have been proven, he or she is also unsure if laws are subject to change. This seems to be a contradiction. |
|
HG5 (5) |
-Theories exist in the natural world and are uncovered through scientific investigations (L).
-Laws are not subject to change (L).
-Theories can change (O).*
-Theories explain laws (L).*
|
-Laws are not theories that have been proven (L). *
-Laws are not subject to change, but they can be manipulated (Airplanes fly because they manipulate the law of gravity.) (O).
|