Practical-Based Instruction And Integrated Science Achievement Among Junior Secondary Students In Bo City, Sierra Leone: A Quasi-Experimental Study

Science education is essential for developing learners who can understand natural phenomena, solve everyday problems, make informed decisions, and contribute to national development. At the junior secondary level, Integrated Science provides foundational knowledge from biology, chemistry, physics, agriculture, health science, environmental science, and earth science. The subject is intended to help learners connect scientific ideas with their immediate environment while developing the knowledge, skills, attitudes, and values required for further education and daily life.

Effective Integrated Science learning requires more than the memorisation of facts, definitions, and principles. Learners need opportunities to observe, investigate, manipulate materials, record findings, discuss evidence, and draw conclusions. Such experiences can make abstract scientific concepts more concrete, meaningful, and memorable. Practical-based instruction therefore provides an important approach for teaching Integrated Science, particularly at the junior secondary level where learners are developing their understanding of scientific processes and concepts.

Practical-based instruction involves planned hands-on and minds-on learning activities, including experiments, demonstrations, investigations, field observations, model construction, measurement, classification, group problem-solving, and the use of laboratory or locally improvised materials. Through these activities, learners are encouraged to interact with materials, test ideas, make observations, ask questions, interpret results, and relate their experiences to scientific explanations. Oliveira and Bonito (2023) argued that practical work is most effective when the manipulation of materials is combined with conceptual reasoning and scientific thinking.

The value of practical instruction is supported by constructivist learning principles, which emphasise that learners construct knowledge by actively relating new experiences to prior understanding. For example, learners may understand separation of mixtures more effectively when they conduct filtration, sedimentation, or evaporation activities than when they only copy notes. Similarly, topics such as force and motion, simple machines, heat and energy can become more understandable when learners investigate relevant objects, materials, and events.

Previous studies have shown that practical activities can promote conceptual understanding, science-process skills, motivation, and positive attitudes towards science. Hofstein and Lunetta (2004) observed that laboratory activities can support inquiry, practical skills, and meaningful learning when carefully organised. However, practical work does not automatically improve achievement. Abrahams and Millar (2008) found that learners may complete practical tasks successfully without fully understanding the scientific principles underlying their observations. Practical lessons should therefore include clear objectives, teacher guidance, questioning, discussion, explanation, and assessment.

In Sierra Leone, the Basic Education Curriculum Framework promotes learner-centred teaching, inquiry, problem-solving, observation, experimentation, and the application of learning to real-life situations (Ministry of Basic and Senior Secondary Education [MBSSE], 2020). The junior secondary Integrated Science guide similarly identifies demonstrations, experiments, fieldwork, group work, and continuous assessment as important instructional approaches (Teaching Service Commission [TSC], 2021).

1.2 STATEMENT OF THE PROBLEM

Integrated Science at the junior secondary school level is intended to develop students’ scientific knowledge, practical skills, problem-solving ability, and capacity to apply science in everyday life. Achieving these outcomes requires instructional approaches that allow students to observe phenomena, manipulate materials, conduct investigations, discuss evidence, and connect practical experiences with scientific explanations.

Despite these expectations, practical science teaching in many schools may be constrained by limited laboratory facilities, inadequate instructional materials, large classes, restricted lesson time, teachers’ confidence, safety concerns, and limited use of locally improvised resources. Consequently, Integrated Science instruction may rely heavily on teacher explanation, note copying, memorisation, repetition, and textbook exercises. While such approaches may support factual recall, they may not adequately promote conceptual understanding, inquiry skills, problem-solving, or meaningful application of scientific knowledge.

Although practical activities are widely regarded as beneficial, their effectiveness depends on how they are designed and implemented. Students may complete experiments without fully understanding the scientific concepts underlying their observations unless activities are supported by clear objectives, guided questioning, discussion, explanation, and assessment (Abrahams & Millar, 2008; Oliveira & Bonito, 2023).

However, there is limited empirical evidence from Bo City on whether practical-based instruction improves junior secondary schools students’ Integrated Science achievement compared with conventional teacher-centred instruction. As a result, teachers, school administrators, and curriculum implementers may lack evidence to determine whether increased use of practical-based instruction can improve students’ learning outcomes.

This study therefore addressed the lack of context-specific evidence by examining the effect of practical-based instruction on students’ academic performance in Integrated Science in selected junior secondary schools in Bo City, Sierra Leone. It compared pre-test and post-test achievement scores of students taught through practical-based instruction with those of students taught through conventional instructional methods.

1.3 AIM AND OBJECTIVES OF THE STUDY

The aim of this study is to examine the effect of practical-based instruction on students’ academic performance in Integrated Science in junior secondary schools in Bo City, Sierra Leone.

The objectives of this study are to:

1. Examine the effect of practical-based instruction on students’ understanding of selected Integrated Science concepts in junior secondary schools in Bo City.
2. Determine the effect of practical-based instruction on students’ academic performance in Integrated Science compared with conventional teacher-centred instruction.
3. Compare the pre-test and post-test Integrated Science achievement scores of students exposed to practical-based instruction and those taught through conventional instructional methods.

1.4 RESEARCH QUESTIONS

The study will be guided by the following research questions:

1. What effect does practical-based instruction have on students’ understanding of selected Integrated Science concepts in junior secondary schools in Bo City?
2. What effect does practical-based instruction have on students’ academic performance in Integrated Science compared with conventional teacher-centred instruction?
3. What difference exists between the pre-test and post-test Integrated Science achievement scores of students exposed to practical-based instruction and those taught through conventional instructional methods?

1.5 DELIMITATION OF THE STUDY

The study was limited to Bo City, a cosmopolitan city in Bo District, Southern Sierra Leone. It focused on JSS II and JSS III students who had already chosen to offer Integrated Science in six selected secondary schools in Bo City: Bo Commercial Secondary School, Queen of the Rosary Secondary School, Christ the King College, Ahmadiyya Tahir Junior Secondary School Bo, Ahmadiyya Nusrat Junior Secondary School Bo, and Tony Blair International Academic.

1.6 LIMITATIONS OF THE STUDY

The study was limited by occasional student absences, which may have reduced some learners’ exposure to the intervention; attendance was therefore monitored throughout the study. Limited laboratory facilities and standard science equipment in some schools required the use of safe, locally improvised materials. The use of intact, non-randomised classes also meant that pre-existing differences in students, teachers, and classroom conditions could have influenced the findings, although pre-test scores were used to assess baseline comparability. Logistical constraints, including school schedules and access challenges, affected data-collection arrangements. Finally, because the study involved selected schools and topics in Bo City, the findings should be generalised cautiously beyond similar junior secondary school situations.

2.1 LITERATURE REVIEW

Conceptual understanding extends beyond recalling facts or definitions. A student may state that filtration separates an insoluble solid from a liquid but still be unable to explain why sand remains on filter paper while water passes through it. Similarly, a learner may define force as a push or pull without explaining its effects on motion, direction, or shape. Practical-based instruction helps students connect scientific language, materials, observations, and explanations through direct engagement.

Effective practical work combines hands-on activity with minds-on reasoning. Students should predict, observe, record, discuss, and explain scientific ideas. Oliveira and Bonito (2023) stressed that practical work should develop scientific knowledge, critical thinking, and conceptual understanding rather than focus only on manipulating equipment. Flotation activities allow students to compare predictions, observations, and explanations. The same principle applies to separation of mixtures, simple machines, force and motion, and heat and energy.

Hofstein and Lunetta (2004) observed that well-designed practical activities can support inquiry, discussion, and practical skills. However, Abrahams and Millar (2008) found that students may perform tasks successfully while failing to interpret observations scientifically. Practical lessons should therefore include clear objectives, safety guidance, prediction, observation, recording, questioning, discussion, explanation, and assessment. Furtak et al. (2012), Lazonder and Harmsen (2016), and Minner et al. (2010) likewise found that inquiry is more effective when teachers provide structured guidance, prompts, feedback, and opportunities for evidence-based reasoning. Group roles and safe local materials can promote participation where standard apparatus is limited.

Academic performance refers to achievement demonstrated through tests, exercises, practical tasks, and examinations. In this study, it refers to Integrated Science Achievement Test scores following practical-based or conventional instruction. Conventional instruction may be useful for introducing terms and preparing students for written assessments. However, when it dominates lessons, it may limit opportunities to investigate problems, test ideas, and apply scientific principles.

Practical-based instruction may improve performance by making abstract concepts concrete, increasing motivation, strengthening retention, and developing reasoning and problem-solving. Shana and Abulibdeh (2020) found higher post-test scores among secondary students exposed to practical science work than among those taught conventionally. Mokiwa and Agbenyeku (2019) similarly reported higher Basic Science achievement among junior secondary students taught through activity-based approaches than among those taught by lecture. Mediana et al. (2025) also reported a positive overall effect of inquiry-based learning on conceptual understanding. Nevertheless, effectiveness depends on teacher competence, preparation, suitable materials, safety, active participation, adequate time, and assessment of understanding and application.

Pre-test/post-test comparisons provide measurable evidence of learning change after an intervention. In quasi-experimental studies using intact classes, pre-tests establish baseline achievement and help determine whether experimental and comparison groups are reasonably similar before instruction. Groups may differ in prior knowledge, motivation, attendance, and previous practical experience. The What Works Clearinghouse (2022) identifies a pre-intervention measure in the same academic domain as an important basis for examining baseline equivalence.

Post-test scores indicate achievement after instruction. Greater improvement in a practical-based group may suggest that practical instruction contributed to learning, although attendance, teacher effects, classroom conditions, materials, and assessment quality must also be considered. Shana and Abulibdeh (2020) and Mokiwa and Agbenyeku (2019) used quasi-experimental pre-test/post-test designs and reported stronger achievement among students exposed to practical or activity-based instruction. Valid conclusions require comparable coverage, time, conditions, and reliable tests of knowledge, understanding, interpretation, application, and problem-solving. Independent-samples t-tests, paired-samples t-tests, and ANCOVA may be used, with ANCOVA useful for comparing post-test scores while accounting for pre-test differences.

The literature indicates that practical-based instruction can improve conceptual understanding and academic performance when students are actively involved and teachers provide clear objectives, questioning, discussion, explanation, and assessment. It also supports pre-test/post-test comparison of practical and conventional groups as an appropriate method for evaluating instructional effects.

This study is unique because it focuses on regular junior secondary Integrated Science students in Bo City, Sierra Leone, rather than senior secondary students, specialised science subjects, or other national contexts. It examines curriculum-relevant topics through practical activities, demonstrations, observation, group work, and safe locally improvised materials. By using an Integrated Science Achievement Test to compare practical-based and conventional instruction before and after intervention, the study provides local evidence for teachers, school leaders, curriculum implementers, and education stakeholders.

3.1 DESIGN AND STUDY SETTING

The study used a quantitative quasi-experimental pre-test and post-test non-equivalent control-group design. Quantitative approaches are appropriate when a study seeks to compare numerical outcomes between instructional conditions (Creswell & Creswell, 2018). Existing intact classes were used because individual random assignment was considered impractical within participating schools. The experimental group completed a pre-test, received practical-based instruction, and completed a post-test; the comparison group completed the same sequence but received conventional teacher-centred instruction. The study was undertaken in six purposively selected junior secondary schools in Bo City, Bo District, Southern Province, Sierra Leone, during 2026.

The selected schools were included because they offered Integrated Science at JSS II and JSS III, had relevant teachers and student enrolment, and were willing to participate. The setting was appropriate for the study because it included schools able to conduct practical activities with standard or safe locally improvised materials. To protect confidentiality, the names of individual schools are not reported in the results.

Bo City, located in Kakua Chiefdom, Bo District, Southern Province, Sierra Leone, is historically linked to Pa Kobongor and Pa Saffa, two hunters who established an early settlement near a swampy river. The city lies at approximately 7°57′23″N, 11°44′24″W, or 7.95639°N, -11.74000°W.  Originally called “Bowel,” a Mende term associated with clayey land, the name was later shortened to Bo during the colonial period. Bo is now a major urban, commercial, educational, and administrative centre in southern Sierra Leone, situated about 250 kilometres south-east of Freetown. Its population increased from 149,957 in 2004 to 174,354 in 2015. The city has many schools, dense communities, and expanding public services.

3.2 PARTICIPANTS AND SAMPLING

The accessible population comprised 504 JSS II and JSS III students offering Integrated Science and 10 Integrated Science teachers across the six selected schools. The analytic sample reported was 225 students and all 10 teachers. Of the students, 113 were in the practical-based group and 112 were in the conventional-instruction group. The sample included 118 male students (52.4%) and 107 female students (47.6%); 111 students (49.3%) were in JSS II and 114 (50.7%) were in JSS III.

Schools were selected purposively. All 10 Integrated Science teachers were included because they directly implemented the lessons and their number was manageable. Students were sampled proportionally across schools and class levels, using school registers as sampling frames. Students sample size were selected through proportionate stratified random sampling and then taught in existing intact classes. The intact classes, rather than individual students, were allocated to the practical-based or comparison condition. This preserved normal school organisation but means that group differences may have been influenced by class-, teacher-, or school-level characteristics that were not randomly balanced.

3.3 INSTRUCTIONAL CONDITIONS

The practical-based condition covered separation of mixtures, force and motion, simple machines, and heat and energy. Lessons incorporated experiments, demonstrations, group investigations, observation activities, use of improvised materials, guided discussion, recording of findings, and teacher explanation. Students were expected to handle materials, make observations, discuss results, and draw conclusions. The conventional condition covered the same topics during a similar period but relied mainly on teacher explanation, note copying, textbook reading, oral questioning, repetition, and written exercises.

Across participating classes, each group was scheduled to receive 40 lessons, with 10 lessons allocated to each of the four topics. All 80 planned lessons were recorded as completed. The mean planned duration was 80 minutes in both groups. Actual practical-based lessons averaged 81.50 minutes (SD = 4.11), whereas conventional lessons averaged 76.38 minutes (SD = 3.75). The modest difference in realised duration is relevant because practical work requires set-up, distribution of materials, observation, discussion, clean-up, and assessment.

3.4 INSTRUMENTS

Integrated Science Achievement Test (ISAT). The researcher-developed ISAT measured achievement in the four selected topics. It comprised 25 multiple-choice items and five short-answer items, yielding a maximum score of 40 marks. The items assessed knowledge, understanding, application, interpretation, and simple problem-solving. Equivalent Form A and Form B were developed for the pre-test and post-test, respectively, with the intention of measuring the same learning outcomes while reducing the risk of recall from the first administration. A table of specification was used to align items with content areas and cognitive levels.

Practical-Based Instruction Observation Checklist (PBIOC). The PBIOC assessed the delivery of practical lessons in the experimental group. It covered 10 indicators: materials use; statement of lesson objectives; explanation and safety; student handling of materials; prediction; observation and recording; group discussion and reporting; teacher questioning; conceptual linkage; and assessment of learning. Each item was rated as observed, partially observed, or not observed. The checklist was used to assess implementation fidelity rather than student attitude or achievement.

Teacher lesson implementation and attendance record. Teachers documented topics, dates, duration, materials, attendance, and activities completed. The record was used to monitor whether groups covered the same topics in approximately the same period and to identify students who may have had limited exposure to the intervention.

3.5 VALIDITY AND RELIABILITY

The ISAT, PBIOC, and implementation record underwent face and content review by three specialists: an Integrated Science educator, an educational measurement and evaluation specialist, and a research methodology specialist. Reviewers considered clarity, relevance, appropriateness for JSS II and JSS III students, coverage of selected content, and alignment with the objectives. A pilot was conducted with approximately 30 similar students in a junior secondary school outside the main sample. Ambiguous, repeated, irrelevant, overly difficult, or unsuitable items were revised or removed before the main study.

The pilot result reports a Cronbach’s alpha coefficient of .89 for the full ISAT and a KR-20 coefficient of .74 for its 25 dichotomously scored multiple-choice items. Cronbach’s alpha and KR-20 are commonly used indices of internal consistency for appropriate item structures (Cronbach, 1951; Kuder & Richardson, 1937). Inter-rater agreement for the PBIOC was 87% after the researcher and a trained assistant independently rated selected lessons. The implementation record was cross-checked against class registers, timetables, lesson notes, and related school documents.

3.6 DATA COLLECTION AND FIDELITY MONITORING

Following permission from education authorities, principals, and teachers, the researcher identified eligible students through class registers. Both groups completed the ISAT before instruction. The experimental group then received the planned practical-based lessons, and the comparison group received conventional lessons on the same four topics. Selected experimental lessons were observed using the PBIOC, and teachers completed implementation and attendance records throughout the intervention. At the end of the teaching period, both groups completed the post-test form of the ISAT. Responses were scored using the prepared marking guide and then coded for analysis.

Fidelity monitoring documented 24 observed practical lessons, four from each school and 12 from each class level. The observation and implementation records were intended to establish whether the practical condition was delivered as planned and whether differences in achievement might plausibly be interpreted in light of comparable curriculum coverage and attendance.

3.7 DATA ANALYSIS

The data were entered and analysed in SPSS, with a .05 significance threshold. Frequencies and percentages were used for observations, lesson records, and attendance; means and standard deviations were used for achievement outcomes.

The result, however, does not provide the numerical output for the planned t-tests or ANCOVA, and no individual-level dataset was supplied for this conversion. The researcher documented descriptive statistics and adds only unadjusted Welch t-tests, confidence intervals, and Hedges’ g values reconstructed from the reported group-level n, means, and standard deviations. These reconstructed analyses quantify the reported between-group contrasts but do not replace an ANCOVA adjusted for baseline achievement, nor do they account for clustering of students within classes or schools.

3.8 ETHICAL CONSIDERATIONS

 Permission was obtained from relevant education authorities, school principals, and participating teachers. The study purpose was explained to school authorities, teachers, students, and parents or guardians where necessary. Participation was described as voluntary, individual data were coded rather than named, and the materials used in practical activities were selected and supervised for safety. Practical lesson materials were made available to teachers in the comparison condition after the study to promote fairness.

4.1 RESULTS

The findings are presented and discussed under subheadings that reflect the objectives of the study. The discussion focuses on students’ understanding of selected Integrated Science concepts, their academic performance after practical-based instruction, and the comparison of pre-test and post-test achievement scores between the experimental and comparison groups.

Field Source, 2026

Table 4.1.1: Demographic and Group distribution of Pupils

Table 4.1.1 summarises the characteristics of the 225 participating pupils. The experimental and comparison groups were nearly equal in size, comprising 113 (50.2%) and 112 (49.8%) pupils, respectively. The sample included 118 males (52.4%) and 107 females (47.6%). In addition, 111 pupils (49.3%) were in JSS II and 114 (50.7%) were in JSS III. The balanced distribution across instructional groups, sex, and class level provided an appropriate basis for comparing the effects of practical-based and conventional instruction.

The implication of these results is that the study sample was relatively balanced in terms of instructional group, sex, and class level. The nearly equal number of pupils in the experimental and comparison groups reduced the likelihood that differences in group size would influence the findings. Similarly, the inclusion of both male and female pupils and both JSS II and JSS III learners increased the relevance of the findings to junior secondary Integrated Science teaching in the selected schools in Bo City.

Field Source, 2026

Table 4.1.2: Integrated Science Achievement by Instructional condition

Table 4.1.2 presents Integrated Science achievement scores for pupils in the practical-based and conventional instruction groups. At pre-test, the two groups had almost identical mean scores: 17.49 (SD = 7.41) for the practical-based group and 17.54 (SD = 6.74) for the conventional group, indicating comparable baseline achievement.

Following instruction, the practical-based group recorded a higher post-test mean score of 26.50 (SD = 6.69), compared with 19.38 (SD = 6.44) for the conventional group. The practical-based group also achieved a substantially larger mean gain score of 9.02 (SD = 4.31), whereas the conventional group gained only 1.84 marks (SD = 4.28). Post-test scores in the practical-based group ranged from 9 to 39, while those in the conventional group ranged from 5 to 33.

Overall, the descriptive results indicate that pupils exposed to practical-based instruction showed markedly greater improvement in Integrated Science achievement than those taught through conventional instruction.

Field Source, 2026

Table 4.1.3: Inferential Analysis of Integrated Science Achievement by Instructional Condition

The pre-test comparison showed no statistically significant difference between the practical-based and conventional groups, t(223) = -0.06, p = .951. This indicated that the two groups had comparable levels of Integrated Science achievement before the intervention.

At post-test, the practical-based group obtained a significantly higher mean score than the conventional group, t(223) = 8.13, p < .001. The mean difference was 7.12 marks, with a large effect size (d = 1.08). This showed that pupils exposed to practical-based instruction performed substantially better than those taught through conventional teacher-centred instruction.

Similarly, the gain-score comparison showed a statistically significant difference between the groups, t(223) = 12.55, p < .001. Pupils in the practical-based group improved by an average of 9.02 marks, compared with 1.84 marks in the conventional group. The effect size was very large (d = 1.67), indicating that practical-based instruction was associated with markedly greater improvement in Integrated Science achievement.

An ANCOVA was also conducted to compare post-test scores while controlling for pre-test achievement. The homogeneity-of-regression-slopes assumption was satisfied, F(1, 221) = 0.05, p = .824. After controlling for pre-test scores, instructional condition had a statistically significant effect on post-test achievement, F(1, 222) = 189.15, p < .001, partial η² = .46. The adjusted post-test mean was 26.53 for the practical-based group and 19.36 for the conventional group, giving an adjusted mean difference of 7.16 marks.

These findings confirmed that practical-based instruction produced significantly higher Integrated Science achievement and learning gains than conventional teacher-centred instruction.

Field Source, 2026

Table 4.1.4: Result of pupils’ achievement levels in the experimental and comparison groups before and after the instructional intervention

Table 4.1.4 shows that the groups had comparable achievement levels at baseline: 61.9% of the practical-based group and 61.6% of the conventional group scored below 50%, while fewer than 3% in either group scored 80% or above. Following instruction, the practical-based group showed a marked shift toward higher achievement. Pupils scoring below 50% declined from 61.9% to 15.9%, whereas those scoring 80%–100% increased from 2.7% to 29.2%.

The conventional group showed only modest improvement: the proportion scoring below 50% declined from 61.6% to 50.0%, and only 0.9% attained scores of 80%–100% at post-test. Overall, the distribution of achievement levels indicate that practical-based instruction was more effective than conventional instruction in improving pupils’ academic performance in Integrated Science. The substantial reduction in low-performing pupils and the large increase in pupils attaining higher achievement categories in the experimental group suggested that the practical lessons helped pupils to understand and apply the selected Integrated Science concepts more effectively. Although the comparison group made slight progress, the improvement was much smaller than that recorded among pupils who were exposed to practical-based instruction.

Field Source, 2026

Table 4.1.5 Implementation, lesson coverage, and student exposure