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Asia-Pacific Forum on Science Learning and Teaching, Volume 16, Issue 1, Article 4 (Jun., 2015) |
In general, students do not perceive science lessons in relevance to daily life and see them merely as content that is learned at school (Ledbetter, 1993). However, it is very important that students recognize how science process skills learned in science classes, such as search and inquiry, can be applied to problems they encounter in their daily lives. Learning science is not remembering content, but also learning to master the science process skills and to apply those skills in scientific investigation (Jeenthong, Ruenwongsa and Sriwattanarothai, 2014). Students who have these kinds of experiences will realize the usefulness of their knowledge, learn how to reach sources of knowledge, and produce new knowledge using their present knowledge. In order to achieve this result, students should learn the scientific research process (Gay, Mills & Airasian, 2009:5). The scientific research process can be taught through using science process skills (American Association for the Advancement of Science, 1989). The scientific research process can be described as identifying a problem, gathering data, analyzing the data and interpreting the gathered results (Fraenkel & Wallen, 2006:7). Therefore, scientific research develops students’ higher level thinking skills, such as asking questions, doing research, solving problems (Cuevas, Lee, Hart, & Deaktor, 2005). In fact, we know that science process skills are related to scientific research process (Aydoğdu, Erkol & Erten, 2014). Science process skills help students to become active individuals in the learning process (Çepni, Ayas, Johnson, & Turgut, 1996). Using science process skills is an important indicator of transfer of knowledge which is necessary for problem-solving and functional living (Akinbobola & Afolabi, 2010). Therefore, these skills are necessary for individuals living in a rapidly developing society. Individuals with these skills have the ability to make a major contribution to the improvement of society.
Individuals who have science process skills have learned to solve problems (Aktamış & Ergin, 2007) and have developed higher-ordered thinking skills. Science process skills (SPS) are among the most frequently used thinking skills (Gagne, 1965: 145; Aydoğdu, Tatar, Yıldız-Feyzioğlu & Buldur, 2012), and their acquisition is one of the most important aims of science teaching (Bybee & Deboer, 1993). Myers, Washburn & Dyer (2004) stated that SPS form the basis of science, enabling individuals to discover the results at their research and inquiries results, so enabling students to acquire these skills in science education is extremely important. SPS are not only used in the learning-teaching process at school, but are also used in daily life (Rillero, 1998; Karslı & Şahin, 2009). Therefore, everyone, not only scientists, should acquire these skills (Huppert, Lomask & Lazarowitz, 2002). Rillero (1998) emphasized that individuals who cannot use SPS will have difficulty succeeding in daily life. Therefore, these skills affect the personal, social, and global lives of individuals (Aktamış & Ergin, 2008). Similarly, Roth & Roychoudhury (1993) stated that students who frequently used SPS to solve open-ended questions were more academically successful. Harlen (1999) and Ferreira (2004) highlighted the importance of science process skills to the acquisition of scientific literacy in science teaching. Science teaching thus needs to be redesigned in a way that emphasizes science process skills (Saat, 2004).
SPS are defined as tools for acquiring information about the world and for ordering this knowledge (Osborne & Freyberg, 1985; Ostlund, 1992). Harlen (1999) claimed that students who cannot adequately learn SPS may not understand the world around them and form the necessary connections. Tobin & Capie (1982) defined SPS as identifying a problem, formulating a hypothesis about the problem, making valid predictions, identifying and defining variables, designing an experiment to test the hypotheses, gathering and analyzing data, and presenting rational findings that support the data. These skills are handled in the related literature in two categories: basic and integrated SPS (Yeany, Yap, & Padilla, 1984; Burns, Okey & Wise, 1985; Carey, Evans, Honda, Jay & Unger, 1989; Rubin & Norman, 1992; Germann, 1994; NRC, 1996; ;Martin, 2003; Saat, 2004). Basic SPS form the basis of integrated science process skills. Therefore, the basic SPS are designed to provide a foundation for learning the more complex integrated SPS (Padilla, 1990; Rubin & Norman, 1992; Rambuda & Fraser, 2004). While basic SPS includes skills like: observing, classifying, communicating, measuring, using space/ time relationships, using figures, inferring and predicting, integrated SPS include skills like identifying the problem, identifying and controlling variables, formulating hypotheses, interpreting data, defining operationally, reading/constructing graphs and experimenting (Yeany, Yap, & Padilla, 1984; Padilla, 1990; Germann, Aram & Burke, 1996; Martin, 2003; Turiman, Omar, Daud & Osman, 2011; Chabalengula, Mumba, & Mbewe, 2012). Generally, basic SPS can be acquired from the preschool period onward while integrated SPS can begin to be acquired in secondary (5th through 8th grades) school (Ergin, Şahin-Pekmez & Öngel-Erdal, 2005: 7), as students are in the concrete operational stage during preschool and primary school (1st through 4th grades). On the other hand, the formal operational stage starts in secondary school. A study conducted by Padilla, Okey & Dillashaw (1983) found that there was a positive and high correlation (r=0.73) between students’ integrated SPS and formal operational skills. In this context, when students go to secondary school they are expected to acquire integrated SPS. Acquisition of SPS becomes deeper in higher stages (Çepni & Çil, 2009: 52).
This study aims to examine preservice science teachers’ skills of formulating a hypothesis and identifying variables in detail. Since only preservice science teachers’ skills of formulating a hypothesis and identifying variables shall be examined in this study, those skills are given in detail below.
Formulating Hypotheses
It is easier for any individual who has developed the skill of formulating hypotheses to create conceptual knowledge (Lawson, 2001). For this reason, individuals’ skill of formulating a hypothesis must be developed. A hypothesis is defined as describing possible results of a study suppositionally (Abruscato, 2000:46; Fraenkel & Wallen, 2006:46). Turgut, Baker, Cunningham, Piburn, & Roger Cunningham (1997) described a hypothesis as a possible explanation of events or a possible solution to a problem, whereas Martin (2003:132) described it as a statement of the best anticipation of correlation between two variables. Sittirug (1997) indicated that the formed hypothesis should reflect the research design. While constructing a hypothesis, the relationship between variables should be considered (Martin, 2003: 133). In this study, the stated definitions of hypotheses were accepted. Abruscato (2000:46) specified that any hypothesis to be formulated should depend on observations or arguments. For example, students may observe that a cube of sugar will melt faster in hot water than it will in cold water. On the basis of this observation, the students may formulate the hypothesis that all substances that can dissolve in water will dissolve faster in hot water than in cold water. A hypothesis may also be produced from an argument. For example, if a glass jar is put on a burning candle, the candle will be extinguished in a short time. One may formulate the argument on the basis of this observation that the candle was extinguished due to lack of oxygen. Later, the students may formulate the hypothesis that the candle covered by the glass jar will be extinguished when the oxygen the in jar is depleted (Abruscato, 2000:46). Since hypotheses can be formulated in different structures, probable structures of hypotheses are examined in detail in this section. Hypotheses can be constructed in two different ways: as a null hypothesis and as an alternative (research) hypothesis. A null hypothesis (H0), indicates that there is no difference or relationship between two variables; an alternative (research) hypothesis (H1) indicates that there is a difference or relationship between variables (Gay, Mills & Airasian, 2009:6). Alternative hypotheses are examined in two groups: H1 (one-directional) and H1 (non-directional). In an H1 (one directional) hypothesis, the direction of the difference or correlation between the variables is stated while in H1 (non-directional) hypothesis, the direction of the correlation between the variables is not stated (Fraenkel &Wallen, 2006).
Identifying and Controlling Variables
One of the most significant components of research is the variables. Variables can be divided into three categories: dependent, independent and control (Lawson, 1995: 43). Independent variables are any factors or conditions in an experiment voluntarily changed by a researcher; dependent variables are any factors or conditions that may be affected as a result of this change. Finally, control variables are the variables that should be kept fixed in an experiment (Ramig, Bailer, & Ramsey, 1995). In order to conduct a controlled experiment, identifying dependent, independent and control variables is very important (Saat, 2004). When variables can be clearly defined and controlled, better results are achieved (Turgut et al., 1997) because the ability of any researcher to make any research question open depends on his/her ability to determine the variables and control them (Ramig, Bailer, & Ramsey, 1995). When conducting an experiment, only one independent variable’s effect on the dependent variable should be examined, and depending on the study’s aim, other variables should be kept unchanged (Padilla, 1990; Abruscato, 2000:45; Martin, 2003:127). Children cannot intuitively know that they are required to identify and control variables in any research. This requires ability to perceive which there is more than one attribute to given object and which could not only be seen in object’s physical properties but also in the behaviors of objects. For example when we think about a toy truck, the children should be able to perceive that the same toy truck may go faster or slower. This requires perception of interaction between the two occurrences (for example, affecting the speed of the toy truck, roughness of the surface etc.) (Martin, 2003:127). In such an experiment, the dependent variable may be determined as the speed of the truck and the independent variable may be determined as the roughness degree of the surface and the control variable may be determined as the initial speed of the truck.
As it is known, the questions for measuring basic and integrated science process skills of students are given in Trends in International Mathematics and ScienceStudy (TIMSS) which allow international comparisons. Turkey participates in those TIMSS examinations in certain periods with 4th and 8th grade students. It is extremely significant to determine the level of students studying in Turkey in terms of science process skills through TIMSS examinations. In the general ranking the TIMSS-1999 and TIMSS-2007, Turkey was 33rd of 38 and 31st of 50 countries, respectively. In the TIMSS-2011 results, 4th and 8th grade were ranked 36th of 50 and 21st of 42, respectively.
An analysis of the TIMSS-1999 questions showed that some of the questions were intended to evaluate students’ knowledge about scientific research and the nature of science. The headings under scientific research and the nature of science are the scientific method (formulating a hypothesis, making observations, inference, generalization), designing experiments (experimental control, materials and processes), scientific measurements (validity, repetition, experimental mistakes, consistency, scale), using scientific equipment, carrying out routine experimental processes, data collection, organization, representation (units, tables, images and graphics), and describing data and interpretation (Bağcı-Kılıç, 2003). An analysis of the content of the TIMSS-2007 questions showed that there were reasoning questions. Questions evaluating reasoning skills consist of problem solving skills, conducting analysis and synthesis, formulating a hypothesis, making predictions, designing experiments, and the planning, deducing and generalizing, and evaluating stages of an experiment (National Center for Education Statistics-NCES, 2007; Bayraktar, 2010; NCES, 2011). TIMSS-2011 was adapted from the content of TIMSS-2007. These results indicate that in Turkey, primary school students’ knowledge of science process skills is low (NCES, 1999; 2007; 2011). In the TIMSS-2011 examination, questions for assessing students and teachers are given. Teachers were asked what kind of practice exercises they prepared for the students. When the answers given by the teachers participating in Turkey were examined, it was determined that they generally had the students perform practice exercises containing knowledge and understanding in the classes (80%), and less frequently hypothesis formulation and scientific study design (20%). Those results indicate that the teachers commissioned in Turkey are over the international average in terms of giving attention to activities containing knowledge and understanding (78%), but they are lower than the international average for hypothesis formulation and scientific study design (21%). In fact, the statements of the teachers are parallel to the low scores that the students studying in Turkey gained in the TIMSS-2011 examination.
Some studies about primary school students’ knowledge of science process skills in Turkey observed that the students’ average scores were low (Temiz, 2001; Tan & Temiz, 2003; Aydoğdu, 2006; Çakar, 2008; Hazır & Türkmen, 2008). Studies conducted in Turkey show that high school students have poor science process skills (Dönmez & Azizoğlu, 2010; Şen & Nakipoğlu, 2012). The same is true at the university level. These studies identified that the science process skill of preservice science teachers are weak (Akar, 2007; Aydoğdu, Yıldız, Akpınar & Ergin, 2007; Bağcı-Kılıç, Yardımcı & Metin, 2009; Karslı & Ayas, 2010; Aydoğdu, Buldur & Kartal, 2012; Demarrias & Tanrıverdi, 2012; Çelik & Özbek, 2013). However, the acquisition of sufficient science process skills is very important for preservice science teachers. Studies have shown that teachers who have stronger science process skills were more successful in teaching science process skills as compared to teachers with poorer science process skills (Aydoğdu, 2006). Therefore, it is extremely important that preservice science teachers (who will soon be teaching) should both have strong science process skills and be able to transfer these skills to their students. Previous studies have examined preservice science teachers’ skills of formulating a hypothesis and, found that their skills were low (Aydoğdu, Yıldız, Akpınar & Ergin, 2007; Bağcı-Kılıç, Yardımcı & Metin, 2009; Tatar, Karakuyu & Tüysüz, 2011). Other studies analyzed preservice science teachers’ skills of identifying and controlling variables and found that these skills were also low (Ateş, 2005; Aydoğdu, Yıldız, Akpınar & Ergin, 2007; Bağcı-Kılıç, Yardımcı & Metin, 2009; Saka, 2012). Other studies conducted in this field showed that preservice science teachers’ science process skills were poor, but the reasons for this poor performance were not analyzed in detail.
In this study, preservice science teachers were first given two scenarios (Scenario-1 & Scenario-2) containing two different research problems, which examined in detail preservice science teachers’ skills of formulating a hypothesis and identifying variables. Then, pre-service science teachers were divided into three groups, and three pre-service science teachers were selected from each group. They were asked to teach formulating a hypothesis and identifying variables based on two scenarios (Scenario-3 & Scenario-4) and observed for confirmation. Therefore, this study is limited to formulating a hypothesis and identifying variables, which is two of the integrated science process skills that preservice science teachers should gain.
Aim of the study:The aim of this study is to examine preservice science teachers’ skills of formulating hypotheses and identifying variables.
The research question and sub-research question related to the study performed for this aim are given as follows.
Research Question
How well can preservice science teachers formulate a hypothesis and identify variables?
Sub-Research Questions
- What is the accuracy level of preservice science teachers in formulating hypotheses and identifying variables skills?
- While formulating a hypothesis, which hypothesis structure (H0, H1-non-directional and H1-directional) do preservice science teachers use?
- What are preservice science teachers’ mistakes in identifying variables?
- According to preservice science teachers, what causes their mistakes in identifying variables and formulating a hypothesis?
