Use of Modified Laboratory Instruction for Improving Science Process Skills Acquisition N. K. Goh, K. A. Toh, L. S. Chia Institute of Education, 469 Bukit Timah Road, Singapore 1025, Republiqof Singapore One ofthe aims of the present science curriculum development in Singapore, is to prepare students for acquisition of cognitive thinking and investigative skills (science process skills) ( I ) . I t is a common belief that the latter can be acquired through laboratory experimentation. As a result, in Singapore high schools about one third of the curriculum time isdevoted to laboratory work in each of the pure science sut~jects:viz., Chemistry, Physics, or Biology at "0" level. The mode of assessment of the laboratory work is based on the written report of a practical examination (2). As a consequence of this, teachers emphasize getting the "correct" answer and often resort to the verification of something that is alreadv known. Under such a scenario, how can students' acquisition of science process skills be improved? The Modified Laboratory lnstructlon Framework In light of the above, we have constructed a modified laboratory instruction (MLI) in the area of qualitative analysis. The conceotual framework of the MLI is shown in the figure. It depicts how the development of process skills can be svstematicallv achieved and also how the acauisition of succ process skills may, in tum, determine the students' achievement in science ~racticals.The direction of each arrow in the figure is intekded to convey the importance of a preceding action on the outcomes of another action. In operational terms, MLI can be divided into two levels. At Level 1, the study makes use of handouts and assignments for "Mental Preparation" and "Following Instructions" to provide the necessary foundation. Mental preparation involves eettine students to ~ r a c t i c ementallv some of the manipulative s k h . The tecliique used in mental practice is the strateev of " eettine students to "feel" their way through the skill sequence &her consideration (3). Here the students studv the information given in the handouts in the comfort of their homes. ~hese-handoutsare designed to include pictorial representation of certain manipulative skills. They also provide the "what", "why", and "how" of qualitative analysis, which are important for mental practice of the skills involved. In going through the handouts/assignments, the students are "trained" to follow instructions. At the staee of Level 2. the Drocess skills (desiened from simple to complex) are ;ntrokuced systemkicaky to the learners. At the same time. continual monitorina of the ~ r o cess skills by the teacher '(through direct ohse&ationand markine of worksheets) serves t o ensure that learning of these skills takes place.For the area of qualitative anaGsis we have identified three clusters of skills-manipulative, observational, and inferential-as the essential- process skills. These would also be relevant for, say, quantitative analysis. Some of the MLI features t h a t should perhaps be highlighted are:
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1. The logical thinking and reasoning underlying the steps used in
the analysis are illustrated or explained. It is hoped that students can follow these idess and understand the objectives and ratio-
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Journal of Chemical Education
LEVEL 2
Formative monitoring to ensure mastery
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---- Mani&ulJztive
\ Observational Skills
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LEVEL 1
Handouts and assignments given to provide foundation
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Mental Preparation
Following Instructions
nale. This is to avoid the situation where many students just follow instructionsblindly without thinking about what they are doing. 2. The design stressea the relationship and pattern by which inferences can be drawn from observations. In particular, emphasis is placed on: the nature of the reagent used (i.e., its function as an acid, a orecioitant. or an oxidizinz aeent. etc.). how iogicaldeductions can h i made frim the observations. Wherever possible, the organization of instructional materials is Piaget-based.A high proportion of open-ended questionsis used. 3. The student is encouraged, Like any good scientist, not to ignore information that presents itself, whether expected or unexpected. It is from the scientist'scuriositv leadine him or her to investieate further an unex~eetedasoec
