The effect of constructivist science teaching on 4th grade students’ understanding of matter

Research design

In this study, the pre-test post-test control group of quasi-experimental research design was used (Cohen & Manion, 2000). The design of the study can be represented as follows:

Experimental G.	O1 (Pre-Test)	X (Constructivist Science Teaching)	O2 (Post-Test)
Control G.	O3 (Pre-Test)	(Traditional Science Teaching)	O4 (Post-Test)

The experimental and control groups have not been equated by randomization. However, quasi-experimental designs are applied to “much educational research where the random selection of classrooms is quite impracticable” (Cohen & Manion, 2000, p.169).

Participants

This study was conducted with 33 fourth grade students at a state primary school in the Babaeski-Kirklareli district located in the Northwestern part of Turkey during the autumn term of the 2007-2008 academic year. Students were divided into two groups, a control group (CG, n=17) and experimental group (EG, n=16). Groups were regular classrooms.

Table I. Description of the sample.

Gender	Grade 4 Control Group	Grade 4 Experimental Group	Total
Girls	10	7	17
Boys	7	9	16
Total	17	16	33

Data collection

The preparation of the research instrument

Initially, an achievement test consisting of 20 open-ended questions for the unit on matter was developed taking into account the views of chemistry, science and classroom teachers. The preparation of the questionnaire items took into account both the content and curriculum objectives of the 4th grade level textbook unit titled “We Shall Learn about Matter.” Then a questionnaire including 20 questions (13 questions about matter and its states, 7 questions about mixture, melting and dissolving) was pilot-tested in order to ensure the clarity of questions and to check the effectiveness of the research instrument. The pilot study was administered to a total of 15 fifth grade children from the same state primary school. This process provided valuable insights in relation to revision of the questionnaire. There was no particular problem concerning children’s understanding of questions, but a few responses led us to be aware of an interesting misconception and to include a question “Do you think that tomato is matter?” in the final questionnaire. Another point to be considered in the main phase of the study was the time given for the administration of the questionnaire. In the pilot study, this took around 35 minutes, which was too long for its successful administration. In addition, the scope of the literature review seemed to be too extensive in order to complete the study in the planned time. Therefore, the researchers eliminated 7 of the questions about mixture, melting and dissolving, and the final version of the achievement test included 13 open-ended questions about the matter and its states.

The application of the research instrument

The application of the study was completed in six weeks. During the first week, pre-tests were applied to both the CG and EG, in order to see whether there were differences in achievement between the groups. During the following four weeks, the EG was taught using the constructivist teaching practices in science lessons (four hours per-week) while the CG was taught using the traditional teaching practices based on direct speech and question-answer. In the last week, the post-tests were carried out to determine the effects of the constructivist teaching approach on student learning.

The application of teaching activities

The researcher (classroom teacher) carried out the teaching in both the CG and EG. For the EG, teaching materials and course plans were prepared in accordance with the science program. They included experiments based on scientific reasoning, concept maps, games, worksheets, signboards and meaning analysis tables. Keeping in mind the constructivist view that meaningful learning requires students’ existing ideas to be initially elicited, challenged and then exchanged with scientific ones, the teacher always started the lesson by asking questions to students about the topic of matter. Taking the students' preconceptions into consideration, the teacher organized the classroom activities to clarify misconceptions and to aid the development of a scientific view. According to the constructivist learning theory, students need to interact with objects in order to actively engage in the learning situation, and therefore, a great variety of matter was brought to the classroom for activities, e.g. a tomato, a newspaper, some vinegar, water, soil, rice, olive, soap, flour, bread, cream and rubber. Students were given many opportunities to use their knowledge in different situations.

During the science lessons, students usually worked in groups of four. They were often encouraged to share their ideas and talk about what they were doing. The aim was to help students go through the reasoning involved in the application of related concepts about the matter and its states. Below are a few examples of the teaching activities experienced by the experimental group.

The teacher entered the classroom with a bag containing various substances (e.g. a tomato, a newspaper, a rubber, a pencil, a soil, a stone, soap, a spoon, a button, wood and a nail). Directing several questions to the students, the teacher drew their attention to each of these items and then asked the students to list which objects represent matter and which do not. The students actively engaged in classifying each substance into groups. During this process, the teacher guided students through some critical questions such as: “What do we know about the features of matter?” and “Do you think that something around us could be called both matter and another name?”. Students seemed to experience difficulty in classifying the tomato as a matter. The teacher then gave a tomato and a blank card to each group, and instructed the students to think, “Is it a matter? Please, write your reasons on the card.” When they wrote down their answers based on the group consensus, the teacher redirected their attention to the front of the classroom to share and discuss their statements as a whole class. Questions were encouraged from the students. Later, this engagement was followed with a meaning analysis table. Students filled in the table for each item, based on the questions; “Is it matter?” and “What are its physical features?”

In another lesson, the teacher delivered various materials to each group of students, including some sand, limestone, flour, salt, a piece of plastic, a stone, a pebble and some sugar. The students were requested to categorize these substances based on their states. Blank cards then were given to each group. The name of the substance and the group consensus as to the state of the matter was to be written on one side of card, and the reason for the classification state on the other side. This categorization revealed many misconceptions the students held about the states of the various matters, e.g. sand is the state of powder, grain or liquid. The teacher considered the students’ misconceptions when organizing teaching activities and presented new substances in order to provoke the students’ thinking. For example, she gave a glass of water, vinegar, sugar and sand to each group and let them touch the materials. The students put their fingers into each substance and observed the changes on their surfaces. Later they put a spoonful of water, sugar and sand on a flat table, and talked about their appearances. Afterwards, each group crumbled limestone into pieces (dust) and commented on the state of limestone dust. During this process, the teacher moved around the classroom to assist groups, and directed students’ attention to the features of the states of matter. This created a good opportunity for the sharing, discussing and exchanging of students ideas, and seemed to be very effective in enhancing students’ understanding of the states of matter.

Teacher also benefited from games in the EG. For example, after reminding that all matter is composed of small particles, the teacher instructed students, “When I call out a state of matter, you must move like the small particles at that state.” Students stood up by their desks (solid). Students walked slowly around (liquid) and walked quickly or ran around the classroom (gas). Participating in such a demonstration game seemed to facilitate the students’ understanding of the states of matter as student pairs then successfully completed worksheets. Students even continued to play this game in their free time.

In the CG, the topic of matter was presented in a traditional, teacher-centered style by the same teacher (the researcher). The teacher followed only the textbook, but did not bring any matter-related materials or examples to the classroom. Demonstrations and inquiry questions were rarely used during the teaching process. Exercises in the textbooks have been done as a whole class rather than in small groups. During the class, the focus of teaching was on the teacher’s questions instead of the students’ questions. Very little time was provided for student questions and the exchange of views among students.

Data analysis

Initially, the content analyses of data were made for the students’ responses to the open-ended questions. The questions revealed different ranges of responses in terms of their accuracy. Analyses were conducted for each of the questions. Students’ responses to the questions have been categorized mainly as scientific, partially scientific and non-scientific in the tables. The scientific category represents mostly correct answers, while the partially scientific category includes partially correct responses or some correct incidences of scientific information. The non-scientific category includes incorrect responses or those that are not accepted as correct from a scientific viewpoint. However, there were considerable differences in children’s non-scientific responses in terms of the accuracy of their reasoning in relation to the scientific phenomenon in the question. Therefore, further classification of non-scientific responses was considered to be a necessity. Their non-scientific responses have been further classified as either misconceptions or nonsensical. The misconception category represented non-scientific beliefs, conceptual misunderstandings or preconceived notions, which do not match what is known to be scientifically correct. Nonsensical responses were those that are nonsense and unreasonable. For example, the statement “tomato is not matter because we eat it” was categorized as a nonsensical response, while the response “tomato is not matter, it is vegetable” was categorized as a misconception.

All categorization of responses were made based on the consensus of both researchers. After the number and percentage of each type of response was determined, a comparison of the responses between the CG and EG was made using a chi-square test to see if there were significant differences between them.