The effect of an instructional intervention on enhancement pre-service science teachers’ science processes skills

Participants

This study was conducted with 38 PSTs who took the LASE-I course in the Department of Mathematics and Science Teaching at the Faculty of Education at a state university in Turkey. The participants were educated to become science teachers for 5-8 grades in elementary schools. With respect to background of the participants of laboratory and science teaching courses, they took the courses of the general physic lab I-II (2 term), the general chemistry lab I-II (2 term), and the general biology lab I-II (2 term). They have not yet enrolled to the science teaching methods course before the LASE-I course.

Research Design

In this study, one group pretest-posttest preexperimental design (Ary, Jacobs, and Sorensen, 2010) was employed. At the beginning of the study, the Test of Scientific Process Skills (TSPS) was administered as pretest to measure SPSs of the participants. Next, an instructional intervention was performed by embedding inquiry-oriented activities into the LASE-I course. The instructional intervention is explained in detail in the procedure section. At the end of the semester, the TSPS was employed as posttest to measure the SPSs of the participants enrolled R-LASE-I course. Differences were then evaluated by comparing the pretest and posttest scores. The study lasted for approximately 12 weeks during one academic semester. Both quantitative and qualitative data collection tools were used to collect data in order to triangulate multiple data sources to enhance the validity of the study (Fraenkel and Wallen, 2009). Data collection was spanned the whole one semester in which PSTs were enrolled in the laboratory applications in science education-I course.

Data Collection Tools

The tools to collect data included The Test of Scientific Process Skills (TSPS); Analytic Criteria Scale of Designing Experiment, Checklist of Line Graph, and Tabulating Data Skills Test (TDST); the worksheets and/or experiment reports of the PSTs; and a question form.

The Test of Scientific Process Skills (TSPS) which was developed by Burns, Okey, and Wise (1985) and adapted into Turkish by Geban, Aşkar, and Özkan (1992) was administered to define integrated process skills of the participants. The TSPS instrument consisted of 36 multiple-choice questions that tested the students' ability to identify the integrated SPSs. The test includes five sub-sets process skill objectives (identifying variables, identifying and stating the hypothesis, operationally defining, designing investigations and graphing and interpreting data). The Cronbach’s alpha reliability coefficient of the test was found 0.716 for the participants. The TSPS was administered to the participants both at the beginning and the end of the semester.

Analytic Criteria Scale of Designing Experiment, Tabulating Data Skills Test (TDST), and Checklist of Line Graph developed by Temiz (2007) were utilized as scoring tools in order to quantitatively analyze the performance of the participants by means of worksheets and experiment reports. I selected these instruments because of including explicitly performance criteria. I used the analytic criteria scale of designing experiment to assess the PSTs’ skills to plan, and conducted a simple experiment for testing their hypothesis. This scoring tool consists of 4 subcategories (such manipulated variable, responding variable, controlled variables, and testing hypotheses), and maximum 7 point could be received. I employed the tabulating data skills test (TDST) and the checklist of line graph in order to assess the skills of recording data by constructing data table, graphical representation, and graph interpretation. The TDST involves 6 subcategories (such as table title, table structure, name of variables, using appropriate units of variables (if there is), recording data, and organisation), and maximum 15 point could be taken. The checklist of line graph also encloses 6 subcategories (such as titles, scaling and naming the axes properly, drawing a proper graph using data and organisation), and the maximum point was 20. PSTs’ written and observed performances were coded such as 3, 2, 1, or 0 according to the level of fulfilment of the expected responses.

The worksheets and/or experiment reports of the PSTs were used as qualitative data resources and to collect information on problems on the PSTs’ use of SPSs. The worksheets and/or experiment reports are important data tools reflecting the participants’ performances in using SPSs (Harlen, 1999). Therefore, they were collected throughout the semester to enable tracking the PSTs’ performances of using their SPSs. At the beginning of the study, the worksheets with scaffolding were given to draw attention to some elements such as variable-based scientific practices. As the study continued, -although the themes of the worksheets could be different according to their openness degree of the practical lab activity- in general, the parts of the worksheets included a research question or a scenario to capture students’ attentions, the hypothesis, let’s practice activity, let’s record data, let’s draw a conclusion, and what did I learn from this activity.

A question form which was consisted of 3 parts was administered at the end of the semester in order to find out the PSTs’ opinions about the effect of the course. The first part of the question form developed by the researcher consists of 19 questions including 12 positive and 7 negative items. For example, as positive items; the course session was effective on enhancing my own scientific process skills, and I realized my insufficient aspects of using my own scientific process skills through this lab course; and as negative items; I'm not sure I have developed my scientific process skills items were given. This part was 3-point Likert type categorized as yes, somewhat, and no. The second part of the question form was adapted from the survey questions from Hoefnagels and Rippel’s study (2003). Accordingly, the questions were first translated into Turkish by the researcher, and then an educational expert in both languages checked the appropriateness of the language of the questions. In addition to the original questions, one question was added to the survey by the researcher in order to understand the importance of the effective observation. The questions had three options: I understood this subject very well before this course session, I now understand this subject much better, and I still don’t understand this subject very well. The third part of the question form included three open-ended questions: (1) What do you think about the effect of the R-LASE-I course applied during one academic semester? (2) What are your recommendations about the LASE-I course for future? (3) Did you have difficulties because of performing the instructional intervention within the LASE-I course?

Procedure

Description of the laboratory applications in science education-I (LASE-I) course

The LASE-I is a compulsory course (4 hours per week, 2h lecture and 2h lab implementation), and it covers the importance and objective of laboratory in science education, scientific method and SPSs, test worksheets and test report, measurement and error, worksheets and experiment reports, evaluation and assessment in laboratory.

The LASE-I course is an instructional laboratory course. In this study, it was aimed to make connections between learning to do science and teaching science through various laboratory practical works in the LASE-I course. To this end, an instructional intervention was performed in order to integrate the learning of science process into the flow of the traditional cook-book LASE-I course by embedding inquiry-oriented activities into the R-LASE-I course. Redesigned laboratory activities in different variations from closed-ended to open-ended were used to enhance the participants’ SPSs through individual homeworks and small group assignments in- and off-class. The intervention was supported by means of scaffolding at strategic points such as how a hypothesis is formulated, how graphs and tables are used to present data, how experiment is designed etc. to focus on the desired learning outcomes of SPSs, performance-based assessment, and instructor feedback. The participants worked in groups of 4 or 5. Most of the activities were easy to perform, required little class time, and could easily be modified to their classes in the future. Table 1 briefly compares the traditional LASE-I course with the R-LASE-I course in which an instructional intervention was performed during the study.

Table 1. Comparison of the traditional LASE-I course and the R-LASE-I course

LASE-I course	R-LASE-I course
1. Traditional laboratory experiments were followed as cook-book. Practical activities were usually performed to confirm the theories or concepts.	The learning science process was integrated into the flow of traditional LASE-I course. An instructional intervention was performed by putting purposively emphasize on science process through inquiry-oriented activities. Multiple types of experimental activities from closed-ended to open-ended were used.
2. The PSTs worked in traditional groups of 4 or 5.	The PSTs worked in groups of 4 or 5. A cooperative learning technique was employed. Each group member had roles as recorder, spokesperson, responsible for material etc. and they rotated roles periodically.
3. Content knowledge of science was focused. Procedural knowledge and understanding of science were ignored.	Knowledge and understanding of the content and processes of science were integrated.
4. Improving process skills of science was not purposively emphasized.	Improving process skills of science was purposively targeted.

Additionally, a sample of intervened activity is presented in APPENDIX. Some laboratory activities practiced within the R-LASE-I course are given in the Table 2.

Table 2. Some of the activities intervened over the study

Name of activity	Objectives of science content	Objectives of science processes	Procedure
Let’s become a nutrition detective	Describing the basic chemical composition of carbohydrates, proteins, fats, and vitamins	Comparing and classifying; identifying similarities or differences, critical thinking	Given a question, materials, procedure, and Predict-Observe-Explain task
Is Ayse’s wristlet made of pure gold or imitation?	Defining density, and applications of it	Designing a measurement procedure; measuring; obtaining a value of a derived quantity (density)	Given a scenario and materials
Let’s know properties of the soil around us.	Using pH concept, learning some qualitative analysis techniques	Designing equipment for collecting data; collecting and recording data; making and interpreting tables and/or graphs	Given a question
The car moving to the farthest is looser!	Identifying the force of friction, learning how friction and surface texture can increase and decrease motion.	Identifying and controlling variables; describing relationships between variables; exploring how a dependent variable changes when each of independent variables changes	Given a question
Let’s Design an Experiment (Two of the problems given are below: Problem 1: Mr. Ali needs your help Ali uses antacid drug because he suffers from stomach-aches. Ali wants to take the antacid drug by dissolving it in water. Please help Ali, ‘what affects the rate of dissolving?’ Problem 2: Your friend says he/she uses laundry soda instead of calgon in laundry machine. Which one is more effective to soften the water? Design an experiment to indicate it to your friend.	Defining neutralization; defining rate of a reaction; determining what affects the rate of dissolving Defining water hardness; determining how water hardness can be removed	Designing and conducting a simple investigation	Given a scenario

PSTs were requested to design and conduct investigations through in total four task-oriented inquiry activities based on scenarios given by the instructor/researcher. Following laboratory practical activities, each lecture provided science background knowledge that explained the question under investigation and related natural phenomena. Feedback was given to the participants on their worksheets and experiment reports for each activity, and the participants were encouraged to think about the connection between scientific content knowledge and procedural skills. After completing the activities, through performance tasks, the PSTs were engaged in some aspects of science processes through specially designed 6 activity stations. This station work was adapted from Harlen (1998) with some different activities as assessment exercises. Each PST group of 4 or 5 performed each station-activity based on worksheets including activity directions. PSTs were asked to identify one or two main targeted process/inquiry skills used in each station-activity although there would be more than one SPS for each station-activity. The five targeted SPSs were: Observing, hypothesizing, determining and controlling variables, planning investigations, interpreting findings, and drawing conclusions. Then, each PST group explained their own idea, and discussed their ideas to come to an agreement with other groups on which SPS used. Moreover, an open-ended investigation as final project was assigned to the participants at the end of the term.

Data analysis

The data were analysed through the Statistical Package for the Social Sciences (SPSS). Before comparing pretest-posttest, normality assumption with descriptive statistical values was primarily tested by using Shapiro-Wilk test (n = 36) in order to employ t-test for the paired samples (Skewness = -.471, Kurtosis = -.355, Statistic(36) = .955, p = .155 for TSPS (pre); Skewness = -.421, Kurtosis = .320, Statistic(36) = .950, p = .103 for TSPS (post)). Since pretest and posttest scores showed normal distribution (p > .05), t-test was applied for the paired samples in parametric methods to determine whether there were statistically significant differences in the pre- and posttest scores of TSPS. Obtained data was evaluated at p = .05 significance level. Moreover, considering that pencil-paper assessment might not show students’ real performances on some aspects of investigative work, worksheets and/or experiment reports reflecting the PSTs’ performances were also assessed quantitatively by determining the accuracy of statements and/or by using the scoring criteria developed by Temiz (2007) as mentioned before. For example, skills of identifying problem, identifying dependent and independent variables, and formulating hypothesis were assessed by determining the accuracy of statements (1 point for each correct response) on their reports and/or worksheets. For the skills of controlling variables, it was expected that maximum 4 variables were determined (1 point each). Participants’ performance related to the skills of designing experiment, collecting-recording data and modelling were assessed in the sense of both process and product by utilizing the analytic criteria scale of designing experiment, the tabulating data skills test (TDST), and the checklist of line graph measuring the scoring criteria developed by Temiz (2007) as mentioned in Data Collection Tools section. In context of the skill of choosing proper materials in order to set up the experiment, PSTs were expected to determine maximum 7 experimental materials (1 point each) in order to assess the skills of identifying and using experimental materials. Also, for the skill of analyzing data, correct answers were scored as 4 points, partial correct/acceptable answers were scored as 2 points, and incorrect or blank answers were scored as 0 point. The worksheets and/or experiment reports were rated independently by the researcher and an expert on the science education, and the inter-rater reliability of the performance assessment was established as r = 0.819 at the .05 level. A Pearson Product Moment Correlation Coefficient (r) was also calculated between the posttest score of TSPS and the performance-based assessment scores measured with either by determining the correctness of the statements on the worksheets, or assessing through the criteria developed by Temiz (2007). Furthermore, frequency and percentile values of the distribution of the students’ responses about the course were calculated. The worksheets and/or experiment reports of the participants were examined qualitatively to provide information on the problems using SPSs.