1Ida Bagus Suryadharma, 2Habiddin, and 3Oktavia Sulistina Faculty of Mathematic and Science, Universitas Negeri Malang
1[email protected]; 2[email protected]; 3[email protected]
Abstract: University students’ difficulties in understanding some basic chemical concepts have been an area of interest in recent chemistry education research. Students’ difficulty in understanding triplet representation of chemistry including macroscopic, microscopic and symbolic, is of significant research interest. The lack of availability of chemistry handouts that accommodate this triplet representation is considered as one of the reason for student difficulties. Therefore, providing handouts emphasizing triplet representation in chemistry is a crucial point in general chemistry learning. The aim of this research was to develop a general chemistry handout in triplet representation that would be expected to help students overcome learning difficulties in a general chemistry course. The study was initiated by the identification of the conceptions of incoming chemistry students in the class of 2013, and chemistry students in year 1 in the class of 2012 at Malang State University. Difficulties uncovered from these students were considered as the primary focus to be discussed deeply in the handout. The prototype handout produced was validated by 3 educators considered competent with regard to their pedagogic knowledge and to be familiar with the chemistry content. Generally, all validators concluded that this handout should be recommended for use as a main reference in general chemistry learning. However, a subsequent empiric validation would be needed to produce the final handout suitable to be used widely in general chemistry learning.
Keywords: General chemistry, Teaching material, Triplet representation.
INTRODUCTION
Chemistry students’ mastery of chemical basic concepts obtained in their senior high schools plays a big role in their success in general chemistry class in the university. Some university lecturers generally assume that the incoming students’ have enough preconceptions to deal with general chemistry topics.
Therefore the class is conducted without identifying students’ preconception first. In fact, students get many difficulties in general chemistry class because the lack of preconceptions needed to support this class. As a result, in the next advanced courses such as physical chemistry, inorganic chemistry, analytical chemistry, organic chemistry and biochemistry students’ face a big challenge that generally they cannot overcome.
Carson & Watson (1999) proposed that the mismatch between students’ pre-conceptions and university lecturers expectation is one of the possible causes of students’ difficulty in constructing new knowledges.
Research on incoming chemistry students’ difficulties in fundamental chemistry concepts has been published by many researchers across the world. Marais & Mji (2009) reported that chemistry students year 1 in South Africa generally harbours insufficient pre-conceptions of the next chemistry learning. Habiddin (2011) found that many first year chemistry students’ at State University of Malang struggle with the particulate nature of matter concept and naming simple compound.
Chemistry students’ weaknesses on the prior knowledge for general chemistry class should be identified before they go to the class. Wasacz (2010), Weaver (2009) & Berg (1991) emphasized the significant role of students’ preconception to the success of their future learning. Furthermore, Wasacz (2010) stated that by establishing a framework of where their preconceptions come from and what they are, instructors, will have a better understanding of how to address preconceptions when beginning an organic chemistry course, or perhaps even before.
Another significant aspect that sometimes ignored by school and university teachers is identification students difficulty after students follow the whole learning process. In some circumstances, the assessment of students’ performance so far generally is intended for grading purposes only. Meanwhile, to reflect these results for improving the teaching and learning quality of the next classes is rare. In addition, research results confirm that one of students’ difficulties in chemistry learning is how to deal with the triplet representation of chemical concepts (macroscopic, microscopic and symbolic levels), particularly how to transform one level to another.
The effort in overcoming students’ difficulties in chemistry should be supported by the availability of chemistry handout that accommodate students’ needs. Bennett & Sözbilir (2007) argue that contextual based learning can be an initial effort in improving chemistry students understanding in some chemistry topics. Research result showed that the lack availability of teaching resources is one of factors that caused students in Kenya have low achievements in science (Ndirangu et al., 2003). Therefore, providing handout emphasizing in the triplet representation of chemistry is a crucial point in general chemistry learning.
Therefore, in this study, development of chemistry handout was initiated by the identification of students’
difficulties before and after general chemistry learning. Also, in considering the main classic problem of students in chemistry learning as proved by the huge research result in this aspect, including chemistry students at State University of Malang, this handout is constructed in triplet representation. Kozma and Russell in Talanquer (2011) indicated that to understand and to success in chemistry problem solving, students have to be able in transforming one level of chemistry concept representation to another.
METHOD
This developmental research is planned to be conducted for two years. The first year purpose is to develop chemistry handout with the emphasize of using triplet representation and the second year will be the empirical validation of the handout in order to produce the final handout to be used widely in chemistry learning in the university level. The first year study involved 25 incoming students who have not followed the general chemistry classes and 25 students who have taken a general chemistry class of chemistry education program, State University of Malang. This handout is constructed based 4-D model that is adapted from Thiagarajan, Semmel & Semmel, including Define, Design, Develop, and Dissemination. For this first year, the procedure was ended at the develop stage, while the final stage that is dissemination will be conducted in the second year. The procedure of this development in this first year is described below.
Define
- Development of an instrument to identify students’ preconception before general chemistry class and students’ conception after the class
- Content validity: Instrument produced was validated by three validators Revision of instrument based on feedbacks from all validators
- Test with the purpose to identify students real difficulties as a consideration in developing the handout
Design
- Development of handout Develop
- Content validity. The draft obtained from design step is validated by 3 validators - Revision, based on validator feedbacks
- Small group validation. In this step, the handout draft produced is validated in the small group of students in chemistry education, state university of Malang. The main purpose of this step is to figure out the legibility of this handout as learning source.
- Revision
- Draft 2 (prototype) that will be validated empirically in the real chemistry learning RESULT AND DISCUSSION
Preconception of incoming students
Incomplete understanding phenomena is generally harboured by incoming chemistry students. For example, identification of students’ preconception of the nature of the solution was given in two tasks. In the first task, student’s were asked to explain the definition of a solution. Almost 95% of students provide the expected answer. Meanwhile, in the task 2, when student’s were asked to choose which substances that can be categorized as solution from several substances available, student’s showed the mismatch between what the definition of the solution and what the examples of solution are.
What are the subtances below that can be categorized as a solution?
a. Seawater (NaCl in water) e. brass
b. Air f. lemon juice
c. Gasoline g. tea
d. Bronze h. soft drink Table 1. The example of question about solution
In answering the question of task 2 as displayed in the Figure 1, all students consider seawater, lemon juice, tea and soft drink as solutions. Meanwhile, the number of students who understand that air is an example of solution as well is only 20%; gasoline is chosen by 10% of students; particularly, bronze and brass are chosen by 0% of students.
This phenomena confirm that many students consider a solution as the dissolve of solids in a liquid and the homogenous mixture of liquids. However, the homogenous mixture of gas like air is generally not understood clearly by some students. The homogeneous mixture of solids such as bronze and brass in particular, is considered as the unfamiliar knowledge by all of student’s. By considering that solution is a familiar concept for students, it could be surprising that many students got into difficulty. However, this phenomenon confirms that it is often that a concept which is considered an easy or basic concept in teachers’
or lecturer’s opinion could be considered as a difficult concept for students. Therefore, overestimation of students’ preconception should be avoided by a teacher or a lecturer. Carson & Watson (1999) believed that one of the possible cause of an inefective teaching and learning in chemistry is the different between what students’ preconceptions expected by lecturer are and what the actual students’ preconceptions are.
In addition, this finding strengthens the previous research results in this concept. Students in secondary school showed many misconceptions in solution concept (Demircioğlu & Çağatay, 2014). Because the sample size in their research was small, they recommended to do the same research with the bigger sample in order to obtain the more general conclusion. Similar research published that students assumed a solution containing undissolved solute is a supersaturated solution; undissolved solute is a component of solution (Pinarbaş, Canpolat, Bayrakçeken, & Geban, 2006).
Actually, the finding in this research can be categorized either as a misconception or as an incomplete understanding. In terms of misconception, students believed that a solution should be accompanied by the involving of liquid substances. This conclusion is interpreted from the students’ answers which ignored air, bronze and brass as the examples of the solution. Furthermore, in terms of incomplete understanding, students considered sea water, gasoline, tea as solution examples, but ignoring others solution examples. The same result is published by Adadan & Savasci (2012) that students argued that a solution is a homogeneous mixture of a solid substance dissolving in a liquid (commonly water).
These understanding problems are caused by several factors. Firstly, language barrier. In Indonesian Language, “Larut” as the basic word of “Larutan (solution)” always associated with the involvement of liquid. This using word builds a mindset to the students that “larutan (solution)” always related to liquid, even though they state the definition of solution correctly which is a homogeneous mixture of two or more substances. Actually, this definition is not limited to the use of liquid only. As a consequence, school and university teachers are recommended to make sure that their students understand deeply the meaning of a definition of a concept.
Another example of a language barrier is stated by Gabel (1999), “in English, we are very familiar with expressions in which words in common usage have a different meaning from their meaning when applied to chemistry. For example, we say, “the coffee is strong,” rather than “the coffee is concentrated,” or
“the candy melts in your mouth,” rather than “the candy dissolves in your mouth.” In the USA, the word
“substance” is frequently used as a synonym for matter and it is necessary to say “pure substance” to reduce the ambiguity”. Secondly, the examples of solution displayed in chemistry learning in high schools are always limited to the involvement of the solution as well as the examples provided in their chemistry books.
Therefore, school and university teacher should give more comprehensive explanation and example to prevent this incomplete understanding.
The Quality of General Chemistry Handout in Triplet Representation (Prototype Produced)
As discussed in the Method session, the handout produced in this study is a prototype which needs to be empirically validated in the next step. The quality discussed in this paper is in term of the suitability of this handout to be implemented in teaching and learning. The criteria which was used to describe the quality of this handout as the teaching material in general chemistry class adopted the criteria recommendeed by Candy in Ndirangu et al., (2003). They stated that to determine the suitability of a teaching material, intrinsic intellectual and aesthetic quality aspects are highly recommended to be implemented. Intrinsic intellectual quality refers to:
- The ability of the prepared learning materials to model concepts correctly for easier understanding.
- Adequacy of factual content.
- Correctness of the factual content.
Meanwhile, the aesthetic criterion refers to the respondents views on the quality of visual appeal of the learning materials.
By considering these criteria proposed by Candy in Ndirangu et al., (2003) above, the criteria used to determine the quality of this handout ia discussed below.
- Appealing
This aspect describes how the physical performance of this handout can attract the motivation of student’s to read this handout. All validators stated that this handout has an interesting performance as expected. It implies that in their opinions, the physical performances of this handout including colour, pictures, and other aspects will attract students to consider as a learning material. However, some revision was applied in this aspect based on validators suggestion.
Figure 1. The example revision of physical performance
As provided in figure 1, the validator suggested that the symbolic and microscopic representations should be put in together closely. Therefore, students will recognize both representations in the same time. It believed will be easier for students to understand the symbolic and microscopic representations simultaneously.
- Scientific concepts
This aspect describes how accurate the chemical concepts in this handout. The discussion between validators and writers in this aspect happened in confirming some unclear explanations in this handout.
With several revisions, all validators confirm that chemical concepts explained in this handout is scientifically accepted. Basically, there was no disagreement between the validators and the authors in terms of scientific concepts.
- Relevance
This aspect describes how relevant the concepts in this handout to the student’s grade that is chemistry students year 1. With some revisions, all validator give a good credit to the relevance of the concepts in this handout with the learning needs of chemistry students year 1.
(a) Before revision
(b) After revision
NO2(g) + NO2(g) N2O4(g)
coklat gelap tidak berwarna
Reaksi diatas dapat digambarkan secara mikroskopik berikut ini
+
NO2(g) + NO2(g) N2O4(g)
coklat gelap tidak berwarna
+
The long discussion between validators and authors in this aspect related to the suitability of some concepts to be presented in the teaching material of university students year 1. For example, the validator suggested that the mathematical operation on how to arrive at some formulas in chemistry is not important to be understood by students year 1. Therefore, he/she suggested to present the formula such as without providing the explanation how they arrive at it. Validator argued that the advanced course such as physical chemistry will discuss this formula/equation comprehensively.
- Support
This aspect describes the possibility of the concepts in this handout in supporting students to be successful in the next advanced courses. All validators agrees that the concepts in this handout expected to support students, particularly in physical chemistry class.Validators believed that the concepts presented in this handout are sufficient to support students’ success in physical chemistry and other advanced courses. For example, how to predict rate laws for elementary reactions which is explained in this handout will strongly support students success in chemical kinetic course.
- Triplet representation
This aspect describes the advisability of triplet representation of chemistry concepts and how it can improve their understanding. Some revision proposed by validators in this aspect, such as the adjustment of molecular size, additional explanation to support some pictures, and some verbal explanation of some concepts. All in all, all validator believed that this handout will provide a better insight for students in understanding chemistry concepts. In addition, the triplet representation depicted in this handout considered fit with the concept represented. Therefore, this explanation will overcome students’ difficulties in understanding some chemical concepts. For example, Figure 2 will enrich students insight on the vapor-pressure lowering (colligative properties of solution). Commonly, without this representation students only imagined this concept and it often leads them to make an unscientific interpretation. However, this representation will help students to construct their understanding scientifically.
Figure 2. Microscopic representation of why when a nonvolatile solute is present, the vapor pressure of the solvent is lower than the vapor pressure of the pure solvent,
Bucat and Mocerino (2009) stressed the essential of imagination’s ability in developing visualisation abilities. According to Sanger (2000), microscopic models should be provided in learning, however students will understand better some conceptual questions. Also, Tan, Goh, Chia, and Treagust (2009) underlined that to facilitate students in the understanding of chemical reactions in the experiment of qualitative analysis, teachers are advised to design an activity that provides an opportunity for students to experience the reaction (at the macroscopic level), explain the relevant reactions with chemical equations (at the symbolic level) and use analogy and/or multimedia animations to describe what happens in the reactions (at the sub-microscopic level). Therefore, (Guzel & Adadan, 2013) recommended the application of multiple representational tasks combined with discussion and collaborative activities to aid pre-service chemistry teachers in building their scientific knowledge.
- Higher Order thinking skills
This aspect describes how the concepts displayed in this handout can stimulate Higher Order Thinking Skills (HOTS) of students. With the availability of triplet representation aspect in many concepts, validators predicted that this handout will provide a challenge to the students to explore their HOTS.
Many researchers emphasize the importance for students’ understanding of the three levels in order to
meaningfully understand chemistry. A good understanding in chemistry demands a good ability to cross between the boundaries of the triplet representation (Johnstone, 1991; Treagust et al, 2003).
All in all, all validators confirm that this handout can be used as a main teaching material in general chemistry class.
SUGGESTION
This study provided evidence that school and university teacher should be aware students’
preconceptions before chemistry class is started. In addition, they should be careful in providing some examples in a chemistry learning. Besides, they should be aware of the language barrier in learning
REFFERENCES
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