THE IMPROVEMENT OF STUDENTS’ PROBLEM SOLVING SKILLS IN CONCEPT OF SEPARATION METHOD BY USING PROBLEM BASED EXPERIMENTS.

(1)

Siti Ashri Sahidah Lisdiani, 2013

The Improvement Of Students Problem Solving Skills In Concept Of Separation Method Through Problem Based Experiment

Universitas Pendidikan Indonesia | repository.upi.edu

THE IMPROVEMENT STUDENTS’ PROBLEM SOLVING

SKILL IN THE CONCEPT OF SEPARATION METHOD BY

USING PROBLEM BASED EXPERIMENT

RESEARCH PAPER

Submitted as requirement to obtain degree of Sarjana Pendidikan in International Program on Science Education study program

Proposed by

Siti Ashri Sahidah Lisdiani

0902124

INTERNATIONAL PROGRAM ON SCIENCE EDUCATION

FACULTY OF MATHEMATICS AND SCIENCE EDUCATION

INDONESIA UNIVERSITY OF EDUCATION

(2)

THE

IMPROVEMENT STUDENTS’ PROBLEM SOLVING

SKILL IN THE CONCEPT OF SEPARATION METHOD BY

USING PROBLEM BASED EXPERIMENT

Oleh

Siti Ashri Sahidah Lisdiani

Sebuah skripsi yang diajukan untuk memenuhi salah satu syarat memperoleh gelar Sarjana Pendidikan pada Fakultas Matematika dan Ilmu Pengetahuan Alam

Juli 2013

Hak Cipta dilindungi undang-undang.

(3)

APPROVAL FORM OF RESEARCH PAPER

SITI ASHRI SAHIDAH LISDIANI

0902124

THE IMPROVEMENT OF STUDENTS’ PROBLEM SOLVING SKILLS IN CONCEPT OF SEPARATION METHOD BY USING PROBLEM

BASED EXPERIMENTS

APPROVED AND AUTHORIZED BY:

Supervisor I

H. Hayat Sholihin, M.Sc. Ph.D

NIP: 195711231984031001

Supervisor II

Rini Solihat, S.Pd, M.Si

NIP: 197902132001122001

Head of Study Program of

International Program on Science Education

Dr. Diana Rochintaniawati, M.Ed

(4)

iv

THE IMPROVEMENT OF STUDENTS’ PROBLEM SOLVING SKILLS IN CONCEPT OF SEPARATION METHOD BY USING PROBLEM BASED

EXPERIMENTS

ABSTRACT

This research is conducted under the needs of education to solve ineffectiveness of traditional experiment method which could not provide enough facility in developing student skill of problem solving in science Instruction. This research is aimed to investigate the improvement problem solving skill in 1) domain of problem analysis, 2) domain of problem solving planning, 3) domain of conducting problem solving, and 4) domain of problem solving evaluating as the result of problem based experiment implementation. The method which is used in this research is descriptive quantitative method. Sample of research is gained by using purposive sampling which sample is students in higher achiever class of secondary 2 in one of Cambridge based International School in Bandung. According to research result, it can be concluded that the improvement of students

’skill in problem understanding is categorized as low with n-gain value is 0.1.The

improvement of students’ skills in problem solving planning domain is classified

as medium with n-gain value is 0.6, The improvement of problem solving skill in domain of conducting problem solving is medium with n-gain value is 0.5, and domain of problem solving evaluating improved in high category with value is much as 0.8.

(5)

v Siti Ashri Sahidah Lisdiani, 2013

TABLE OF CONTENT

APPROVAL FORM

DECLARATION

PREFACE………i

ACKNOWLEDGEMENT……….ii

ABSTRACT ………..iv

TABLE OF CONTENT………... v

TABLE LIST………vii

FIGURE LIST……….viii

APPENDIX LIST ………...ix

CHAPTER I INTRODUCTION A. Background………...1

B. Research Problem …...3

C. Research Objective………...4

D. The Significance of Research ………...4

CHAPTER II PROBLEM BASED EXPERIMENT AND PROBLEM SOLVING SKILLS A. Problem based Learning ...5

B. Problem based Experiment...6

C. Problem Solving Skill………...10

D. Content Analysis of Separation Method ……...12

E. Rationale Framework…...15

CHAPTER III METHODOLOGY A. Location and Research Subject …... 19

B. Research Method………... 17

C. Operational Definition ………... 17

(6)

vi Siti Ashri Sahidah Lisdiani, 2013

E. Instructional Tools ………...22

F. Research Instrument ………...24

G. Instrument Development ………...……...29

H. Data Analysis Procedure ………32

CHAPTER IV RESULT AND DISCUSSION A. Result ……….……….... 35

1. The improvement of Students’ Problem Solving Skills in Domain of Problem Analysis………... 38

2. The improvement of Students’ Problem Solving Skills in Domain of Problem Solving Planning ………... 39

3. The improvement of Students’ Problem Solving Skills in Domain of Domain of Conducting Problem Solving ………... 40

4. The improvement of Students’ Problem Solving Skills in Domain of Problem Solving Evaluating ... 41

5. Students’ Response toward Problem based Experiment ……….. 42

6. The Implementation of Problem based Experiment ………...……….. 46

B. Discussion……… 54

CHAPTER V CONCLUSION AND RECOMMENDATION A. Conclusion ………...64

B. Recommendation ……….64

BIBLIOGRAPHY………..………. 66

(7)

vii Siti Ashri Sahidah Lisdiani, 2013

TABLE LIST

2.1. Rationale Framework …………...……...16

3.1.Syntax Arrangement of Problem based Experiment in each meeting …….…………. 22

3.2.Blueprint of Problem Solving Skill Test ……….. 25

3.3.Blueprint of performance test rubric ……….……….……. 27

3.4.Analyses of Instrument Trial………..………...31

4.1. Improvement of Problem Solving Skills ………..……... 36

4.2. Improvement of Problem Solving Skills in Domain of Problem Analysis ……...….. 38

4.3. Improvement of Problem Solving Skills in Domain of Problem Solving Planning….39 4.4. Improvement of Problem Solving Skills in Domain of Conducting Problem Solving ………...40

4.5. Improvement of Problem Solving Skills in Domain of Problem Solving Evaluating ………...41

4.6. Students’ Response toward Science Instruction …...………....43

4.7. Students’ Response toward Problem based Experiment ……….……….44

4.8. Observation Result of Teacher Activity ………...48

4.9. Observation Result of Students Activity ………...51

(8)

viii Siti Ashri Sahidah Lisdiani, 2013

FIGURE LIST

2.1. Problem based Learning Cycle (Silver,2005) ………...……….… 5

2.2. Problem based Learning: Gallet Model ………... 8

3.1. Research Plot ………... 21

4.1.Pre-test and Posttest Comparisons of Problem Solving Test………. 37

4.2.Percentage Comparisons of Teacher Activities during the Implementation……... 50

(9)

ix Siti Ashri Sahidah Lisdiani, 2013

APPENDIX TABLE

A.1. Lesson Plan ………63

A.2. Experiment Module A.2.1. Experiment Module……….…...68

A.2.2. Experiment Module 2 ...……… 69

A.2.3. Experiment Module 3 ……….. 70

A.2.4. Experiment Module 4..……….. 71

A.3. Individual Worksheet .………...77

B.1. Problem Solving Test Blue Print ………...78

B.2. Problem Solving Test Draft ………...87

B.3. Performance Test Rubric ………...92

B.4. Performance Test Draft ………...………..94

C.1. Teacher Observation Sheet C.1.1. Teacher Observation Sheet of 1st Meeting ………..…. 96

C.1.2. Teacher Observation Sheet of 2nd Meeting ………... 99

C.1.3. Teacher Observation Sheet of 3rd Meeting………...…100

C.2. Student Observation Sheet C.2.1. Student Observation Sheet of 1st Meeting ……….. 102

C.2.2. Student Observation Sheet of 2nd Meeting ………..104

C.2.3. Student Observation Sheet of 3rd Meeting ………..106

C.3. Student questionnaire C.3.1. Blueprint of Students’ Questionnaire………. 108

C.3.2. Students’ Questionnaire Draft……….... 110

D.1. Instrument Analysis of Problem Solving Test ……… 112

D.2. Data interpretation of Problem Solving Test Analysis ………113

D.3. Judgment Result ………. 114

(10)

x Siti Ashri Sahidah Lisdiani, 2013

E.2. Data Distribution of Post-Test ……….. 118

E.3. Analysis for Problem Solving Test ……….……….119

E.4. Data Distribution of 1st Performance Data Analysis ………..….120

E.5. Data Distribution of 2nd Performance Data Analysis………121

E.6. Normalized gain Analysis for Performance Test ……….122

E.7. Questionnaire Analysis ………123

E.8. Analysis of Teacher Observation Sheet E.9.1. Analysis of Teacher Observation Sheet in 1st Meeting……… 124

E.9.2. Analysis of Teacher Observation Sheet in 2nd Meeting ……….… 126

E.9.3. Analysis of Teacher Observation Sheet in 3rd Meeting ………..… 127

E.9. Analysis of Students Observation Sheet E.9.4. Analysis of Students Observation Sheet in 1st Meeting ………..…… 128

E.9.5. Analysis of Students Observation Sheet 2nd Meeting ……….…… 131

E.9.6. Analysis of Students Observation Sheet 3rd Meeting ……….……… 133

E.10. Analysis of Worksheet Fulfillment E.10.1.Analysis of Group Worksheet….………...135

E.10.2.Analysis of Worksheet Fulfillment ….………136

F. Documents ……….145

F.1 Covering Letter of Research………..156

F.2 Annotation Letter of Research ………..….... 157

F.3 Documentation……….. 160

(11)

xi Siti Ashri Sahidah Lisdiani, 2013

(12)

1

Universitas Pendidikan Indonesia | repository.upi.edu CHAPTER I

INTRODUCTION

A. Background

The needs of science education are essential to the life challenge where science education is one of important aspects in developing high quality human resources. It is emphasized that science education aims to foster students who eligible for pursuing life challenge by showing excel capacity in solving real life problem. Like other thinking skills, problem solving is quite important to be mastered by students. This competency is essentially important to have by each individual in facing daily life situation where knowledge that they have should be enganged with the problems of daily which is generally have unobvious solution. Problem solving is also fostering better citizenship as Problem Solving Expert Group (PEG) (2010) stated that developement of problem solving includes the willingness to engage with

such situation in order to achieve one’s potential as a constructive and reflective

citizen. The importance of problem solving skills is also reflected while in 2012 OECD develops PISA 2012 Problem Solving Assessment which has objective to measure individual Problem Solving competency of the students as one of basic competency that should belong to the students (PEG, 2010).

(13)

2

the process of problem solving where usually it involves scientific investigation of problem.

In fact, science laboratory activity has only been emphasized on the process of conducting experiment without considering development of problem solving skill. During the implementation of experiment activity which generally uses cookbook method, Students are rarely engaged in the material. Accordingly, Kelly et al. (1994) stated that students can be successful in their laboratory class even with little understanding of what they are actually doing.This methods seems to be effective while most of the time students are be able to conduct laboratory activity successfully. As the impact, the result foster that students intend to perceive if they need to follow instruction and getting the right answer (Unal & Ozdemir, 2013), thereby defining unreachable developing of problem solving.

Based on the argumentation abive, the use of novel method of experiment activity is needed considering that cookbook method fails to meet the requirement of problem solving development.Problem based experiments is triggered to fullfill the needs of improvement in science experimental work from traditional or cookbook model. Problem based experiment is experiment activity which is redesigned using problem‐based learning.

(14)

3

te process of problem based experiment where they are able to apply the concept of knowledge with real situation.

This research is aimed to study the implementation of problem based experiment as the effort to improve students’ problem solving skills. In this study, the implementation will be implemented to secondary level students of 8th Grade in the concept of separation method. Concept determination is reconsidered based on characteristic analysis of the concept where it is contextually related with daily life. This concept is compatible with the characteristic of problem based learning which the problem comes from daily activity and familiar condition that usually faced by students.

B. Research problem

In line with the explanatory backround that has been described, problem that rose in this research is stated in the following question:

“How is the improvement of students’ problem solving skills in the concept of separation method by using problem based experiment?”

1. Research Question

Elaborating the research problem above, the research attempts to explore the following questions:

a. How is the improvement of students’ problem solving skill in domain of problem analysis, problem solving planning, and problem solving evaluating?

(15)

4

c. How is the improvement of students’ problem solving skills in domain of conducting problem solving?

d. How is the improvement of students’ problem solving skill in domain of problem solving evaluation?

2. Research Scope

The problem stated is limited to the aspects a follows:

a. Problem solving skills which is examined in this research refers to problem solving skills domain proposed by Mettes et. Al (1981) included problem analysis, problem solving planning, conducting problem solving, and evaluating problem solving.

b. The concept of separation method which is described is limited to the indicator arranged in Cambridge curriculum for secondary two students.

C. Research Objectives

This research is aimed to investigate the improvement of students’ problem solving skills as the result of problem based experiment Implementation in the concept of separation method.

D. The Significance of Research

(16)

17

Universitas Pendidikan Indonesia | repository.upi.edu CHAPTER III

METHODOLOGY

A. Location and Research Subject

This research is conducted at one of private school in Bandung which is implementing Cambridge Curriculum. The school is determined based on consideration where the school is regularly dealing with curriculum reflecting problem solving skills in its structure.

Moreover, the subject of research is 16 students of secondary 2 in high achiever class. Sampling technique of research subject is determined by using purposive sampling. Accordingly, educational research is often utilized quota/ purposive sampling in difficulty to take probability (McMillan, 2012). Yet, High Achiever Class is taken as the consideration from preliminary study where student’s cognitive achievement is excell as the effort to prevent cognitive load during the implementation.

B. Research Method

Research method used in this research is descriptive quantitative as the purpose if the research is appropriate with this method. Descriptive quantitative method is utilized to describe the phenomena or the condition of certain variables (Arikunto, 2002).

C. Operational Definition

In order to prevent missinterpretation and missconception in understanding some of the term used in this research, therefore some of the terms need to be explained as the following explanation:

(17)

18

activity where the process runs based on problem proposed. The implementation problem based experiment in this research is regarding to the syntax of problem solving process which includes (1) formulating problem, (2) defining the problem, (3) problem analysis, (4) present the informarion techniqally and theoritically, (5) analyse the parameter to solve the problem, (6) Elaborate the alternatives, (7) choosing the procedures and experiments, (8) conducting alternative experiments, (9) validating experiments by group, (10) Judging the best procedures, (11) reporting data from each group (12) discussion of experimental result, (13) report of discussion ,(14) Determine the conclussion, (15) reconsideration of experiment results.

2. Problem solving skill as cognitive ability is defined as the process of understanding,analysing,and identifying problem which has no obvious solution method ,then transform it into alternate solution with basic prior knowledge consideration. The information of students’ problem solving skills is gained by using problem solving test for those domain in which including problem analysis, problem solving planning, and problem solving evaluating. Moreover, performance test is conducted to gain data about students’ problem solving skills in domain of conducting problem solving. Its improvement is seen from normalized gain of pretest and posttest according to Hake (1998).

D. Research Procedure

There are several procedures that are conducted in the implementation of this research. Therefore, the procedure is generally classified into three stages which is note as preparation stage, implementation stage, and analysis and conclusion stage. Each of stage consists of several activities which are conducted during the experiments.

1. Preparation Stage

(18)

19

a. Literature review was conducted in analyzing the information about: 1) problem based experiment, 2) problem solving skills, and 3) learning indicator in the topic of separation method.

b. As the result of literature review, research problem is identified and continuously research questions were arranged.

c. According to the needs in answering research questions, instruments were arranged as tools to obtain data. Arrangement of instrument arrangement including 1) problem solving test, 2) performance test rubric, 3) observation

sheet, and 4) students’ questionnaire.

d. Instructional tools which are including lesson plan and experiment module and worksheet was arranged to help the implementation of problem based experiments.

e. Judgment of instruments was conducted by experts.

f. Trial test of problem solving test instrument was conducted to identify the quality of instrument.

g. The result of problem solving test trial was analyzed.

h. Revision of instruments was done based on judgment result and test item analysis.

2. Implementation Stage

These activities below are conducted in the implementation stage which consists of four main activities. The activities are:

a. Pre-test was conducted to identify students’ preliminary skills b. Treatment was conducted in three meeting, including:

1) 1st meeting : problem solving analysis and procedure designing 2) 2nd meeting : experiment activities and1st performance test 3) 3rd meeting : data reporting

c. Post-test was conducted

(19)

20

Universitas Pendidikan Indonesia | repository.upi.edu 3. Analysis and Conclusion Stage

Analysis and conclusion stages consist of four stages, which are enlisted as follows:

a. All of data which is obtained was calculated b. The result of data calculation was analyzed

c. Discussion was done to elaborate the result of analysis d. Conclusion was obtained based on the result

(20)

21

Figure 3.2 Research Plot

2nd Stage : Implementation

Judgement

2nd Performance Test

Pre-test Treatment & 1st Performance Test Post-test

(21)

22

Universitas Pendidikan Indonesia | repository.upi.edu E. Instructional tools

Instructional Tools that is used in the implementation of this research is enlisted as follows:

1. Lesson Plan

Lesson plan is the design of instructional arrangement that will be used in the implementation.These arrangement is set in every unit of class meeting implemented by the teacher. The arrangement of lesson plan refers to the syntax of problem based experiments proposed by Gallet (1998). There are mainly seventeen syntaxes that should be conducted in one cycle of problem based experiments. However, the implementation of problem based experiments in this research is arranged for only one cycle which syntaxes are divided into three meeting.

Lesson plans were also arranged according to the learning objective stated in the scheme of work of Cambridge IGCSE curriculum for the concept of separation method. The objective are 1) describe methods of separation and purification, and 2) suggest suitable purification techniques. Those objectives were developing while learning indicators were arranged to measure the fulfillment of objectives. The scope of separation method concept includes four technique of separation, there are: 1) Filtration, 2) Crystallization and Evaporation to Dryness, 3) Separation Funnel, and 4) Magnetic Separation. Accordingly the arrangement of lesson plan can be seen in appendix A.1 page 69.

For further description of syntax implementation for each meeting related with learning indicators, the table below is arranged.

Table 3.1 Syntax Arrangement of Problem based Experiment in Each Meeting

Meeting Indicators Problem based Experiment Syntax

(22)

23

Meeting Indicators Problem based Experiment Syntax

Meeting in daily life related to separation method

2. defining the problem, 3. problem analysis ,

4. present the informarion technically and theoritically,

5. analyse the parameter to solve the problem,

6. Elaborate the alternatives, 7. choosing the procedures, 8. choosing the experiments 10.validating experiments by group, 11.Judging the best procedures, 12.Data collection in the way to solve

problem

13. reporting data from each group 14. discussion of experimental result, 15.report of discussion ,

16.Determine the conclusion, 17.reconsideration of experiment

2. Experiment Module

Experiment module is the additional tools that helps the implementation of

lesson plan in real activity. Experimental Module is used to be students’ guidance

(23)

24

Experiment Module consist of both group and individual worksheets which respectively arranged based on syntax and the scope of learning objective of separation method. There are four modules which were arranged based on daily life problem. The problems were synthesized regarding to the concept scope of separation method. The problems are including:

a. Kitchen Tragedy Problem: Involve the concept of separation funnel separation method in separating two substances with different density.

b. Iron Mining : Involve the concept of magnetic separation method in separating paramagnetic-diamagnetic heterogeneous mixture

c. Pure it! : involve the concept of filtration method in purifying heterogeneous solution

d. Salt Farming Problem: involves the concept of crystallization and evaporation to dryness in separating homogenous solution with different evaporation and solubility.

Experimental modules were given in all three meetings as students’ guidance. Each of

part were arranged accordingly with syntax and partially given to students. In order, group worksheets were given during group work. On the other hand, individual worksheet was given when the activity is emphasized on individual work. Further, draft of experimental module can be seen in appendix A.2 page 74.

F. Research Instrument

The analysis of problem based experiment implementation in improving problem solving skill is conducted by using several instruments. The instruments will be elaborated as the following explanation.

1. Problem Solving Skill Tests

(24)

25

solving test is according to problem solving domain proposed by Mettes (1981) which include 1) problem Analysis, 2) problem solving planning,3) conducting problem solving, and 3) problem solving evaluating. However, in line with consideration that conducting problem solving domain is analyzed as technical, thus, this domain is uninvolved in this test.

There are six questions proposed which is arranged in open-ended essay type questions. According to Nitko &Brookhart (2007) essay is compatible to measure thinking skill such as Higher .Each domain is represented in two questions that is arranged according to problem passage give. The arrangement of problem solving skill test can be seen in Appendix B.1 and B. 2 page 82 and 85.

Moreover, the arrangement of Problem Solving Test is illustrated in the following table.

Table 3.2 Blueprint of Problem Solving Skill Test

Problem Solving

Domain

Indicators Topic Question

Number

Problem Analysis Analyze the problem in daily life related to solving steps of separation method proposed

Crystallization and Evaporation method

2

(25)

26

This test is conducted into two phases including pre-test and post-test. Pre test is conducted before students engange into the experiment activity.The objective of pre test is to investigate basic knowledge and students skill so that Students’ problem solving skill can be identified. On the other hand, post test which is conducted after students already have enganged the experiment activity. The purpose of conducting post test is to measure how far is the developement of problem solving skill skill after experiment conducted. Similar to pre-test activity; the type of question used is also essay question.

2. Rubric of Performance Test

Rubric of performance test is arranged as the effort to analyze problem solving skill in domain of conducting problem solving. This domain has different characteristics compare to others where it involves technical skill mastery in separation method.Hence, different instrument is arranged to analyze the

improvement of students’ skill in this domain.

In this research, performance test is used to identify problem solving domain of conducting problem solving. There are three technical skills

(26)

27

In general, the rubrics of performance test regarding to the arrangement of technical skills is described in the table below.

Table 3.3 Blueprint of Performance Test Rubrics

Learning

Indicator

Technical Skills Scoring Indicator

Conduct

7 =Apparatus complete, and clean &dry 8 =Apparatus complete, clean and dry, and arranged correclty

5 = Students is not following the procedure 6 = Student is following the procedure and product is not formed

7 = Student is following the procedure, Mixture is separated in small amount 8 = Student is following the procedure, Mixture is separated in big amount 3. technique of tools, some of tools are broken

6 = Incorrect technique in using separation tools, nothing is broken

7 = Correct technique is using separation tools, some of tools are broken

(27)

28

During performance tests, students were ordered to do experiment activity according to problem solving design that has been arranged before. The tests were conducted two times. The first test was conducted during the implementation of problem based experiment. In this way, students’ prior skill of conducting problem solving can be analyzed. During this test, students were used design of problem solving experiment that they arrange by themselves according to their own problem in group module. On the other hand, the second test was conducted after the implementation. In this test, teacher used performance test draft which is arranged based on problem solving design.

The tests were conducted two times, while the first test was conducted during the implementation of problem based experiment. In this way, students’ prior skill of conducting problem solving can be analyzed. On the other hand, the second test was conducted after the implementation. Furthermore, the result of both 1st and 2nd

performance test is analyzed to identify students’ improvement in conducting

problem solving skill domain. The result is elaborated further in the following explanation.

3. Observation Rubrics

The analysis of teacher and students activity is conducted to identify

implementation quality which is appeared from teacher’s activity coherence with the

syntax of problem based experiment which has been arranged before. In obtaining data, observation rubrics of students and teacher activity were arranged. The arrangement of observation rubrics is in line with syntax sequence and teaching and learning activities arranged in lesson plan. The observation sheet is used to analyze the quality of implementation according to the syntax of problem based experiment.

(28)

29

recorded in the observation sheet which is available by giving score between 0 until 4. Each of score represents the quality of implementation. Further the arrangement of observation sheet can be seen in Appendices C page 102.

4. Questionnaire

In the way to identify students’ response toward the implementation of problem based

experiments, questionnaire of students’ response is used to meet the need. The

questionnaires were distributed to 16 students whom the implementation has been treated.

The Indicators of students’ response are classified into two main indicators, those are: 1) students response toward science instruction through experiment activity, 2) student response toward problem solving skills,. The first indicator is

generally including statements about students’ response toward science instruction and through experiment activity in science classroom activity. On the other hand, the

second indicator is emphasized on students’ response toward the activity of problem

based experiment and the advantage of problem based experiment for the students.

The questionaire is arranged by using Likert Scale where each indicator consists of positive and negative statements. In the arrangement of questionnaire response, students are requires to choose appropriate response in one of category including: 1) Strongly Disagree, 2) Disagree, 3) Agree, 4) strongly Agree. The complete arrangement draft and blueprint can be seen in appendix C.3 page 114.

G. Instrument Development

(29)

30

form of instrument used is in essay form, thus the calculation is only done to identify validity, reability, Difficulty index, and readibility.

1. Instrument Validity

In the term of measurement procedure, validity is the ability of an instrument to measure what is measured. The validity of the instrument itself is depened on the effectiveness of its function in measuring data that is supposed to be collected for the needs of reseasrch.There are various type of validity measurement.In this research, constructive validity is used in evaluating instrument.Meanwhile, to calculate the validity of test item, it is proposed to used the formula of correlation of Pearson Product-Moment Correlation in Sudjana (2005: 144). Theinterpretation of validity is classified into some catogories.The categories is arranged based on Guilford (Suherman, 2003).

2. Reliability

Reability is the degree of concistency and stability of the instrument .Thus,the concept of reability has the meaning where the research tools is consistence and stable, and hence predictable and accurate. In other words, reliable instrument is the tool that gives same result when the measurement is given into the same subject whenever ,wherever,and whoever it is implemented (Suherman, 2003)

In particular, the test is considered as single test as it consists of one set test applied in one group of sample in particular time.The reability is determined by the value of reability coeeficient by using K-R 20 formula (Sugiyono, 2008 : 132). Furthermore , The interpretation of reability coefficient is classified into some categories.The categories is arranged based on Guilford (Suherman, 2003).

3. Difficulty Index

(30)

31

who answer a test item correctly. Difficulty level represent the difficulty degree of test item that is implemented. This index will determine whether the test is classified into easy or difficult. Difficulty index for essay test is calculated by the formula of difficulty level (Sudjana, 2005: 137).Further , the classification of difficulty index is represented according to the criteria of difficulty level in Suherman (2003).

4. Discrimination Power

Discrimination Power of item test represent how strong the test item in differenciating between the sample that able to proposed right answer and wrong answer or blank answer (Suherman,2003). If the test and an item measure the same ability or competence, we would expect that those having a high overall test score would have a high probability of being able to answer the item. We would also expect the opposite, which is to say that those having low test scores would have a low probability of answering the item correctly. Thus, a good item should discriminate between those who score high on the test and those who score low.

Indeed ,discrimination power is supposed to give verification that the test item can be used to differenciate between high achiever and low achiever.In obtaining discrimination power, the formula of discrimination power stated in Tinambunan (1988: 140) is used.Likewise, the classification of Discrimination Power coefficient is described by using the category in Suherman ( 2003).

In identifying the quality of problem solving test, instrument a trial was conducted by applying the test into 25 samples of secondary 2(8th grade) of students which already learnt about separation method topics. The calculation of test item analysis was helped by using software Anates 4.0. In summary, the result of problem solving test quality is presented in the following table below:

Table 3.5 Recap of Instrument Analysis

Test Item

Validity Difficulty Index Discrimination Power Note

Value Category Value category Value Category

(31)

32

According to the table above it is identified reability value of instruments is as much as 0.91 which is categorized as very high. In conclusion, it is determined that the instruments are qualified to be used in the research.

H. Data Analysis Procedure

1. Analysis of Problem Solving Test

Problem solving test is conducted two times as pre-test and port-test. Both of the result of test gain data which is advantageous to analyze domain of problem solving skills in cognitive aspects. The process of data analysis is enlisted in the following explanation.

a. Scoring process

Scoring process is initiated by analyzing right answer based on scoring rubrics stated in blue print. Each of questions is given score from the interval between 0-4. After all of the question analyzed, the total score is calculated and transformed into percentage value by using the following formula

b. Analysis of average skill of Problem solving

The analysis of problem solving is determined by calculating average value from total score in problem solving skill test. The calculation is arranged based on formula stated in Arikunto (2006)

c. Determine problem solving profile in each domain

(32)

33

Determination of score percentage in each domain is conducted in a way of analyzing students profile in each domain. The result of analysis can be used as supporting information of improvement in each domain. The calculation of domain average uses the formula of average value calculation stated in Arikunto (2005).

In identifying problem solving profile, the percentage that has been calculated is categorized by level of problem solving category arranged by Syah (1999).

d. Significance test

To analyse the correlation of pre-test and post-test result, the determination of normalized gain index is conducted. Normalized gain is calculated by using the formula proposed by Meltzer (Wardhani, 2006 :39)

Moreover , to identify the quality of problem solving skill improvement, normalized gain index is interpreted. The criteria used for interpretation process is criteria proposed by Hake (1999).

2. Analysis of Performance Test Rubric

a. Determining Average Score of Performance Test

Performance test generally was conducted by evaluating performance of student in conducting experiment by using performance rubrics as scoring guidance. The calculation is conducted by using average formula calculation ( Arikunto ,2005)

b. Significance test of Conducting Problem Solving Domain

Normalized gain Index is calculated to analyze the improvement of students’ skill in conducting problem solving during 1st performance test and 2nd performance test. The identification of normalized gain index of this test is conducted by using same steps as significance test in problem solving test analysis (see part I.1.d)

3. Rubrics and Student Worksheet analyses

(33)

34

Universitas Pendidikan Indonesia | repository.upi.edu Score =

x 100%

The interpretation of score precentage is categorized into certain level according to Kunjaraningrat (Suherman,2001:6).

5. Questionnaire Analysis

Analysis of students questionnaire is used by classifying data based on alternative answers given. In the time of data analysis,the result of questionnaire is identified by calculating the percentage of response:

P = x 100%

Keterangan : P : Precentage

f : frequence of the answer n : total of the respond.

(34)

58

Universitas Pendidikan Indonesia | repository.upi.edu CHAPTER V

CONCLUSION AND RECCOMENDATIONS

A. Conclusion

Taking into account previous research findings, it can be concluded that students problem solving skills in the concept of separation method through problem based experiment are improved with the improvement of each domain described as:

1. The improvement of students ’skill in problem understanding is categorized as low with n-gain value is 0.1.

2. The improvement of students’ skills in problem solving planning domain is classified as medium with n-gain value is as much as 0.6.

3. Domain of problem solving evaluating improved in high category with value is much as 0.8.

4. The improvement of problem solving skill in domain of conducting problem solving is medium with n-gain value is as much as 0.5.

B. Recommendation

Considering that the implementation is still need to be developed in a way to find perfection, the following recommendations are suggested for further work and research:

1. The analysis of students’ attitude toward the implementation is recommended to be done. This analysis will emphasize the aspect of students’ response toward the implementation.

(35)

59

3. It is recommended to pay attention in arranging group of students considering that most of the syntax involving group work. The appropriate group arrangements will decrease students resistance in activity involvement

(36)

60

Universitas Pendidikan Indonesia | repository.upi.edu BIBLIOGRAPHY

Adesoji, F.A. (2008). “Student’s Ability Levels and Effectiveness of

Problem-Solving Instructional Strategy”. J.Soc.Sci. 17 (1). 5-8.

Al-Irsyad Satya Islamic School. (2012). Scheme of Work Secondary 2 Science. Mathematic and Science Department Al-Irsyad Satya Islamic School.

Ananiadou, K. and Claro. M (2009). “21st Century Skills and Competences for New

Millennium Learners in OECD Countries”, OECD Education Working

Papers, No. 41, OECD Publishing.

Arikunto, S(2006). Dasar Evaluasi Pendidikan (Edisi Revisi). Jakarta : Bumi Cahaya.

Arikunto, S. (2010). Prosedur Penelitian Suatu Pendekatan Praktik. Jakarta: Rineka Cipta.

Anderson, L.W. and Karthwohl. D.R (2001) . “ A Taxonomy for Learning, Teaching, and Assessing”. New York : Longman.

Chang, R. (2007). Chemistry 8th Edition. New York :Mc.Graw Hill.

Chin,C. and Chia L. (2005). “Problem-Based Learning: Using Ill-Structured Problems”. Wiley Periodicals, Inc. Sci Ed 1(90):44 – 67.

Depdiknas. (2006). Kurikulum 2006 Standar Kompetensi Mata Pelajaran. Jakarta: Depdiknas.

Gallet,C. (1998) “Problem-solving teaching in the chemistry laboratory: Leaving the

cooks” Journal of Chemical Education 75 (1).72-77.

(37)

61

Hake, R.R. (1999). Analyzing Change/Gain Scores, available in http: //www .physics.

indiana. edu/~sdi/AnalyzingChange-Gain.pdf. [11 May 2013].

Hmelo-Silver, H.C.E. (2004). ”Problem-Based Learning : What and How Do Student

Learn”. Education Psychology Review. 16 (3). 235-266.

Klegeris,A & Hurren. H. (2011).” Problem based Learning in a Large Classroom Setting: Methodology, Student Perception, and Problem Solving Skill. Advance Physiology Education. 35 (1).418-415.

Mc. Millar, J.H. (2012). Educational Research : Fundamental for the Customer,Sixth Education. Pearson Edcation, Inc: Boston

Mettes CTCW & Pilot (1981). Teaching and Learning Problem Solving in Science. Part II :Learning Problem Solving in a Thermodynamics Course. Journal of Chemical Education. 58 (1).51-55

Nitko,Anthony. Susan M Brookhart.2007. Educational Assessment of Students 5th Edition. New Jersey : Pearson

O’neil, Jr. John Schater. (1997). Test Specification for Problem Solving Assessment.

Los Angeles: The Regents of The University of California

PEG (2010) Pisa 2012 Field Trial Problem Solving Framework.Melbourne : OECD

Polya,G.(1973). ”How to Solve it: A New Aspect of Mathematical Method”.New Jersey: Princeton Inc.

Suherman, E. (2003). Evaluasi Pembelajaran Matematika. Bandung: JICA FPMIPA UPI.

(38)

62

Syah,M. (1999). Psikologi Pendidikan dan Pendekatan Baru. Bandung. Remaja Rosa Karya

UCLES (2009) Cambridge IGCSE Combined Science Syllabus code 0625 For examination in June and November 2013.

Unal,C & Ozdemir O.F (2013). : “A Physics Laboratory Course Designed Using Problem-based Learning for Prospective Physics Teacher”. European Journal of Science and Mathematics Education. 1 (1).29-33.