Thursday, July 20, 2017

How Fair Testing was Brought to Light from Pupils’ Responses in a Science Lesson through Lesson Study

by Rolando M. Tan

Experimental investigations such as those used in science classroom activities entail the need to control certain variables to validate changes observed from a single variable being investigated. This practice follows the fair test principle. Conducting fair test in experimental investigations eliminates the chance of making inconsistent conclusions; instead, it provides opportunity to draw out conclusions based on verifiable and reproducible evidence (Mclleland, 2006). This principle is an important issue in the field of elementary science education as most elementary school teachers have inadequate training and exposure to inquiry-based instruction as a pedagogical model for teaching science (Newman, 2004). This issue was brought out in a Lesson Study on a seed germination activity for fourth grade pupils as a means to foster evidence-based learning through the inquiry approach. The research lesson, prepared by Grade 4 science teachers, was implemented twice with post-lesson discussions that follow after each implementation. 

The first implementation of the research lesson was designed to make pupils infer which variable was able to initiate seed germination of mung beans. The experiment consisted of three setups: Setup A used dry soil, Setup B used wet soil, and Setup C used wet cotton. The pupils were asked to make these setups and to record their observations for four days. On the fifth day, the pupils posted their data on the blackboard and explained their findings including their answers to the questions in the activity. The implementing teacher was not able to see that the setups had two variables that were changed (type of medium and presence of moisture). As a result, the experiment had not been helpful to the pupils as they were only able to answer that water initiated the process of germination from a previous experience. One of them explained that the unexpected germination of the beans in the dry soil setup was caused by the rain that made the setup wet. Some pupils, however, answered that air and sunlight are the factors that initiated seed germination. From the post lesson discussion, the implementing teacher had not realized that the experimental setups in the seed germination activity was flawed and had overlooked how the pupils arrived at their conclusions. The flaw in the experimental setup was discussed during the first post lesson discussion. The lesson study team decided to include an additional setup containing seeds embedded in dry cotton, which will serve as the control for the other setup (seeds embedded in wet cotton). The revised research lesson used a pair of setups which had a wet soil setup and a dry soil setup as the control and another pair of setups which had a wet cotton setup and a dry cotton setup as the control. The lesson study team decided that half of the class will use the dry soil and wet soil setups while the other half will use the wet cotton and dry cotton setups. 

The second lesson implementation of the revised research lesson was implemented by another member of the lesson study team. A four-day observation period was carried out. On the fifth day, the class reported their observations. A discussion on the activity was conducted by the teacher. The teacher asked in vernacular (Tagalog): What is common and what is not in the pair of setups? The pupils responded better as the teacher emphasized the presence or absence of the independent variable by asking questions to make the pupils infer that water initiates seed germination regardless of the kind of medium (cotton or soil) used for germinating mung beans. During the post-lesson discussion, the team saw the need to put Tagalog translations on the research lesson especially on questions where discussion and concept development are constructed by the pupils. 

In summary, the pupils’ responses provided teachers helpful insights on their lesson development. First, the use of the vernacular language facilitated better student engagement in the discussion of the results of the experiment. Second, the experience from the two lesson implementations stressed the importance of how pupils arrive at an answer instead of just focusing only on the answer given by the pupils. This is aligned with the inquiry-based approach of making pupils construct evidence-based statements (BSCS, 2006; NRC, 2000).

The full version of this article is published in UP NISMED’s Lesson Study Book 2: Learning more together, growing in practice together.


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