Asia-Pacific Forum on Science Learning and Teaching, Volume 17, Issue 2, Article 6 (Dec., 2016)
Hüsnüye DURMAZ
The effect of an instructional intervention on enhancement pre-service science teachers’ science processes skills

Results

The results are displayed below by referring to the questions respectively.

(1) Did the SPSs levels of PSTs enhance significantly at the end of the instructional intervention?

In order to analyse the TSPS data, paired sample t-test was used to investigate whether the participants could enhance their level of integrated SPSs. Although the number of participants was n=38, two participants did not complete the posttest. Therefore, the final number of the participants was 36. The means and standard deviation of TSPS for both pre- and posttest are given in Table 3.

Table 3. Results for paired sample t-test of TSPS

 n X(mean) SD Df t p Pretest 36 62.222 4.008 35 10.668 .000* Posttest 36 68.389 2.464

Note: *p< .05

According to Table 3, a significant difference between the pre- and posttest scores of the participants’ SPSs was found (t(35) = 10.668, p < .05). When the means of pre- and posttest (X(pre)= 62.222; X(post)= 68.389) were examined, it was seen that the effect of the R-LASE-I course on the participants’ SPSs was in favour of the posttest.

Furthermore, the frequencies and percentages for the 36 items on the TSPS for both pre-and posttest were analysed in order to determine which item(s)’ rate of correct responding percentage is less than 50%. Consequently, for this sample, the items whose rate of correct responding percentage lower than 50% were 13, 15, 18, 30th item (identifying variables objective), and 27 (an identifying and stating hypothesis) in the pretest. On the other hand, it was found that the rate of correct responding percentages of 13, 15, 18, 30th items was 50% more successful in the posttest. However, for item 27, while the rate of correct responding percentage was 36.1% in the pretest, only 44.4% of participants correctly answered in the posttest. To sum, the lowest rate of correct responding percentage was 44.4% for item 27 in the posttest.

(2) Was there a significant correlation between the scores of the TSPS and performance-based scores of the PSTs?

A Pearson product moment correlation coefficient (r) was calculated to examine whether there was a significant correlation between the posttest score of TSPS and the performance-based assessment score. At the end of the R-LASE-I course, the experiment reports and/or worksheets were also assessed quantitatively by determining the accuracy of statements and/or using the scoring criteria developed by Temiz (2007) as mentioned before.

The worksheets and/or experiment reports were rated independently by 2 raters and the inter-rater reliability of the performance assessment was established as r = 0.879 at the p < .05 level. According to the result, a significant positive correlation at the p < .05 level was found out (r = 0.769) between the scores of TSPS and performance.

(3) What were the problems of the PSTs in using SPSs?

The results of the assessment based on performance of open-ended task are reported in Table 4 below.

Table 4. The results of the assessment based on performance of open-ended task

 Targeted skill Percent of response Hypothesis is formulated correctly. 77.77 Dependent variable is identified correctly. 88.88 Independent variable is identified correctly. 66.66 Controlled variables are determined correctly   -4 and more controlled variables are determined correctly.   -3 controlled variables are determined correctly.   -1 controlled variable is determined correctly. 22.22 66.66 11.11 All materials required of their experiments could be described obviously. 88.88 Data table and/or graph is/are formed. 100.00 Title of table and/or graph is written. 22.22 Data is recorded both forming a table and graph. 50.00 Replication is made.   -3 replications are made.   -2 replications are made. 0.00 25.00 Data is correctly and interpretively interpreted. 100.00 Conclusion is drawn correctly. 100.00 Statement is written whether data obtained is supported the hypothesis. 69.4

Examining the worksheets and/or experiment reports according to the correctness of the statements and/or using the criteria developed by Temiz (2007) revealed the PSTs had some problems as listed below:

1- Concepts of dependent and independent variables were confused with each other, and they were used interchangeably. For example; one PST stated that distance is dependent variable instead of independent variable in the activity of the car moving to the farthest is looser.

2- Non-descriptive variable names were used. For example; one PST defined only x matter instead of the kind of matter, matter mass or volume as controlled variables of the problem what affects the rate of dissolving?

3- Possible relation between dependent and independent variables was not indicated while formulating a hypothesis and more than one independent variable was used. For example; one of the PSTs expressed that my hypothesis is: temperature affect, and other PST mentioned that kind of liquid and temperature affect the viscosity of the liquid in the activity of what affect the viscosity of a liquid.

4- Titles of tables and/or graphics were not either written or appropriately written. For example; one participant wrote just Data Table as the title of the table.

5- Experiment was not replicated.

(4) What were the opinions of the PSTs about the effect of the R-LASE-I course process on enhancing SPSs?

Opinions of the PSTs were gathered from the question form consisted of 3 parts.

For part one, the percentile values of the responses distributed to some of 19 questions about the opinions of the participants on the R-LASE-I course process are displayed in Table 5.

Table 5. Some opinions of the PSTs about the effect of the R-LASE-I course process of the first part

 Items Yes Somewhat No f % f % f % Such lab implementations were exactly new for me 19 50 11 28.9 8 21.1 I prefer the implementations of lab as before 16 42.1 10 26.3 12 31.6 Such lab implementations were more tiring 17 44.7 14 36.8 7 18.4 I did not understand concepts of scientific process skills 2 5.3 8 21.1 28 73.7 The course session was effective on improving my own scientific process skills 23 60.5 12 31.6 3 7.9 My confidence increased on conducting science research 18 47.4 16 42.1 4 10.5 I can use what I learned at a scientific study 25 65.8 13 34.2 - - I want to study a research in more detail 23 60.5 9 23.7 1 15.8 I noticed my inadequacies’ of using the scientific process skills during the course 28 73.7 9 23.7 1 2.6 I understood much better on what I should pay attention in order to develop SPS of my own future students 31 81.6 6 15.8 1 2.6

When Table 5 is examined, it is seen that, for example, 47.4% of the participants affirmed that their confidence increased while conducting science research, 60.5% of them stated that they wanted to study a research in more detail, 60.5% of them answered that the course session was effective on enhancing their own SPSs, 73.7% of them confirmed that they noticed their inadequacies of using the SPSs during the course, and 81.6% of them stated that they understood much better on what they should pay attention in order to develop SPSs of their own future students.

Results obtained from the second part of the survey are shown in Table 6.

Table 6. Responses of the participants about the effect of the R-LASE-I course process of the second part

 Survey questions Responses I understood this subject very well before this course session I now understand this subject much better I still don’t understand this subject very well f % f % f % Formulating hypothesis 6 15.8 31 81.6 1 2.6 Defining dependent variables 3 7.9 33 86.8 2 5.3 Defining independent variables 3 7.9 33 86.8 2 5.3 Defining controlling variables 3 7.9 30 86.8 5 13.2 Developing appropriate controls for an experiment 11 28.9 27 71.1 - - What makes a hypothesis testable 4 10.5 32 84.4 2 5.3 Importance of replication of the experiment 20 52.6 18 47.4 - -

According to the results of the second part in the question form, most of the participants (81.6%) indicated that they understood how to state a hypothesis much better during the course, and the 86.8% thought that they understood how to identify dependent and independent and controlling variables after the course. It was remarkable that although 52.6% stated that they knew the importance of replication of the experiment before this course session and 47.4% of them understood this subject much better via this course, according to data obtained from their performances, nobody made at least 3 replications while only 25% of them made 2 replications.

The open-ended question section as the third part of the question form was examined. Some responses about effect of the R-LASE-I course process and recommendations for the future of the PSTs are quoted below:

One PST said that I had a lot of useful knowledge with even experiments which we firstly thought how simple they were. I learned that I should look to issues more perceptively and critically.

Another PST expressed that the experiments, in general, were not difficult, but we concluded deeper understandings because we thought more on them. On that account, the course was useful for me. I saw that I had much inadequacy of SPSs even with much simple a candle experiment.

Most of the PSTs recommended to have the LASE-I course for the next year that if activities or experiments are chosen from elementary science and technology textbook, it will be more useful on how to enhance SPSs of our own students’ in future.

PSTs’ responses to the difficulties because of performing the instructional intervention within the LASE-I course are identified as follows:

One of the PSTs stated that designing an experiment was a new thing for me; we had done experiments like cookbook by this time. Therefore, we had difficulty in determining a problem and conducting an experiment because we did not know what we would do.

Another PST said that I had difficulty in determining variables, formulating a hypothesis, and designing an experiment because this was the first time we applied those in this lab.

The other PST expressed that I had difficulty in defining dependent, independent, controlling variables, and designing own experiment. I was unfamiliar with such working; we were comfortable doing experiment before because everything was ready in front of us. Someone stressed that such working was not difficult but more time than usual was needed to perform.

Another PST reported that I could determine controlling variables, but noticed that I could not control those by doing experiment.

In the light of the results obtained, it is possible to suggest that the R-LASE-I course had a positive effect on the PSTs in enhancing their SPSs.

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