This study was carried out to determine the examination of small scale experiment in fostering students’ achievement and retention in practical chemistry with reference to ability levels. Six research questions and six null hypotheses guided the study. A sample of hundred subjects drawn from Senior Secondary (SS) II chemistry students in three schools in Enugu North Local Government Area was used for the study. The schools in the study area were grouped into co-educational schools, boys and girls secondary schools. From each of the group, one school was randomly selected by balloting. The co-educational school was made up of 32 subjects while the Boys’ and Girls’ schools were made up of 31 and 37 subjects respectively, making a total of hundred subjects. The subjects divided into two by the chemistry teachers were used for experimental and control group. The experimental group was taught quantitative and qualitative analyses (practical chemistry) using small-scale experiment by their regular chemistry teacher who were trained for the research. The control group was taught using (demonstration) conventional approach to quantitative and qualitative analyses. The instrument, quantitative and qualitative analyses achievement test, (Q2AAT) was developed by the researcher, validated by experts in science education and measurement and evaluation and used for data collection on students’ achievement and retention in practical chemistry. The instrument which is made up of 30 multiple choice items which was administered as pretest. It was reshuffled and administered for post test and further reorganized and administered for retention test. The research questions were answered using mean and standard deviation while the hypotheses were tested using analysis of covariance (ANCOVA) at 0.05 significance level. The result of data analysis showed that:

  1. Small scale experiment was superior to demonstration method in enhancing students’ achievement and retention in practical chemistry.
  2. The high ability students out performed their average and low ability counterparts in quantitative and qualitative aspects of practical chemistry in respect to achievement and retention in chemistry.
  3. Interaction examination of teaching methods (small-scale experiment and demonstration and ability levels on students’ achievement and retention in chemistry were not significant.

One of the implications of this study was that chemistry teachers can use a small-scale experiment (which gives students more opportunity to practice with their hands) in conducting chemistry practical without fear of lowering the achievement levels of students. It was therefore recommended that the small-scale experiments would be included in the training and retraining programme of science teachers. Other educational implications of the findings were highlighted and relevant recommendations were made.



Background of the Study

Science is important in national development because knowledge of science has helped human development in the area of health, communication, transportation, industrialization, food production, education, synthesis and research. Chemistry, as one of the core science subjects according to International Council of Chemical Association (ICCA) (2000), has been found very useful in all areas of life from food and clothing, housing, communications, transport and to other problems in energy sector, information technologies, industries and the waste disposal sectors.

Chemistry is the study of nature and properties of all forms of matter, and various changes they undergo. It involves the making of different substances, finding out their properties and, how they react with one another, finding patterns in this knowledge and attempting to understand properties and phenomena in terms of atoms and molecules and their electronic structures and using their knowledge and understanding to make predictions. Chemistry involves activities which are isolation, preparation and synthesis. Each of these three categories involves practical aspect of chemistry.

Chemistry is typically an experimental science and relies primarily on practical work (Lambert and Holderness 1984). It is the study of the composition, structure and properties of material substances, of the interactions between them, and of the examinations on them, of the addition or removal of energy in any of its several forms (Encarta 2004). Material substances studied in chemistry are made to interact during practical or experimental work to bring out their properties.

Practical chemistry is the experimental method of teaching chemistry and it is always conducted with chemicals and equipment. Practical chemistry helps to consolidate conceptual understanding of chemistry as a subject.  It is not just a subject that can only be taught by theory lessons but a partner in the development of concepts and understanding (Mbajiorgu and Reid, 2004). According to them laboratory work in chemistry should be used for problem solving and development of concepts. The laboratory/practical work helps to inculcate in the students the desired science process skills and attitude needed for problem solving.

Practical lessons are expected to expose students to the acquisition of skills in observation, recording, interpreting, reporting and discussion of matters of scientific interest. Practical science lessons help students to investigate problems and internalise scientific methods and in the ability to manipulate apparatus. All these accruable from practical activities help to boost understanding and foster retention in chemistry.

Practical lessons/activities demand various chemicals and equipment and some of the laboratory equipment and chemicals are often inadequate in schools. Amuka (1996) supported this view and opined that schools in developing countries, of which Nigeria is one, often lack basic facilities, which are indispensable for examination teaching, learning and retention of chemistry concepts.  Inadequacy of laboratory facilities may be due to high cost of the materials which is aggravated by poor funding. Chemistry teaching in many schools has been severely threatened by lack of funds, inability of the teachers to improvise, careless attitudes of pupils to laboratory facilities, lack of laboratory assistants, large practical classes and teachers’ preference to verbal instructions and board notes (Ogunniyi, 1978). Chemistry laboratories demand huge sum of money to get them well equipped. Neither the money required for equipping the laboratories nor chemicals and equipment are made adequately available to schools. Under the condition of insufficiency of laboratory materials, it is not easy to effectively   teach and learn chemistry.

The condition of chemistry laboratories in many public secondary schools (in Enugu State), do not guarantee effective teaching, learning, retention and subsequent good achievement in chemistry. Ohuche in 1995 noted that for basic science subjects (chemistry, Biology and Physics) the number and quality of laboratories were far below requirements across the nation.

Consequently, students’ achievement is poor.   According to West African Examination Council chief examiners reports (1998) the candidates who sat for West African Senior School certificate Examination (WASSCE) exhibited the following lapses:

  • Failure to show details of how derived data were arrived at;
  • Shallow understanding of mole concept;
  • Inability to draw logical conclusions from observations made during tests;
  • Arithmetic errors and omission of units from stated values
  • Non-adherence to instructions, especially, with regard to step wise test and difficulty in relating mole and volumes   which is a necessary requirement for calculating the volume          of acid used in titration. The 2003 Chief Examiners’ reports           still unveiled lapses exhibited by students in WAEC        examinations, most of which stem from inadequate practical   The lapses are as follows:
  • Failure to adhere to instructions.
  • Poor understanding of the demands of the questions.
  • Poor practical exposure and giving theoretical answers to practical questions.
  • Inadequate use of terminologies especially in qualitative analysis.
  • Muddling up of test and introducing of chemicals/ reagents not mentioned in the prescribed tests.
  • Inability to record observations correctly and give logical inferences to observations made.
  • Inability to assign correct charges on anions and cations
  • Poor knowledge of significant figures and
  • Poor calculations, spelling mistakes and omission or wrong units.

With the observed lapses, the objectives of secondary school Chemistry may not be achieved and they are pointer to students’ inadequate practical experiences before external examination.

Students’ exhibition of the above listed lapses means that they were poorly taught. Most of the lapses stem from lack of exposure to adequate and required practical experiences. Students’ poor practical experience has been one of the problems of teaching and learning chemistry. Bomide (1986) in the same view reported that the objectives of chemistry are never adhered to effectively, in the teaching and learning of the subject, due to lack of adequate practical work. Since practical experiences cannot be gained without practice (experiment) and there is need to have   them before final examination in chemistry, where a test for practical skill is a must, an alternative way of teaching the practical lessons must be sought. Such an alternative way of teaching practical chemistry must be cost reducing so that practical lessons could be conducted during the period of insufficiency of laboratory expendables. Examples of applicable cost reducing strategies include demonstration and small-scale experiment. Demonstration as a strategy for teaching practical chemistry reduce cost in the sense that one person conducts the practical while others observe. The expendables which would have been used by the observers are saved and could be used next time for practical lesson.

Small-scale experiment (SSE) on the other hand entails the use of small quantity of chemical(s) of low concentration to conduct practical lessons. SSE provides every student with hands-on-activities to learn practical skills and gain experiences which may improve their achievement and retention in chemistry.  Small-scale experiment, where the use of small quantity of chemicals is possible, is considered in this study as an alternative way of teaching practical chemistry.

Considering the WAEC statistical reports (1998), the poor retention and achievement in chemistry are evident. A total of 185,430 candidates entered for chemistry in WAEC, only 2,771 did not write the examination that year. Among the candidates who sat for the chemistry examination, only 21.39% passed at credit level (C1- 6), 22.25% had pass (P7 – 8) while 52.8% failed.  Altogether a total of 74.53% of the candidates had grades that are presently not useful for further studies.

For 1999 and 2000, 65.73% and 68.10% respectively scored between P7 – F9 and could not use the result for further studies. Only 31.08% in 1999 and 31.88% in 2000 passed at credit (C1 – 6) levels. The remaining percentage did not write the examination.

Therefore for three years, (1998-2000) greater percentage of WAEC candidates for chemistry had scores that could not give them the chances of studying chemistry and chemistry related courses in the higher institutions, thus, the appreciable low enrollment in these areas. Secondly, greater percentage of the secondary school chemistry graduates could not imbibe the knowledge and skills they were exposed to and so could not express the functionality of what they were taught (WAEC 2000). It is expected that secondary school chemistry graduates should at least be able to have the knowledge and skills for fermentation of food and other materials, separation techniques, synthesis of soap and so can be self-employed to some extent.

The overall achievement of students in their academic pursuit relates to their ability levels and retention of what they learnt. Ability means the capacity to perform something successfully. It refers to the general skill or competencies to perform a task. Ability of students means the level or extent of intelligence, skill, knowledge, or experience possessed by the students to do something. This means some students have high ability while some have low ability. Ability of students may be influenced by teaching strategies and methods. Ability levels include both natural and acquired skills and skill proficiency gained through training and experience. Learning sharpens ability and learning according to Lahey (2003) is any permanent change in the behaviour brought about through experience. Whatever experience a child has or learns adds to the child’s ability and can facilitate the learning of a new concept. In other words the ability levels of the learner plays a vital role in the learners’ learning of new concepts. This brings about the differences in what is learnt. Some high ability level students may learn far more than others in a particular learning task. They are followed by average and lastly by low ability learners.

Although ability categorization includes the theoretical learning possibilities of students, the manner of presentation of learning tasks interact with the students theoretical possibilities. Thus, the students of high ability may perform poorer than students of lower ability due the manner of presentation of learning tasks. Will presentation of practical chemistry learning tasks, using small-scale experiment (SSE) and conventional (approach) demonstration method as used this study interact with students’ ability in influencing their achievement and retention of the concepts taught? This study investigated the examination of a cost reducing strategy on students’ achievement and retention in chemistry.

Retention refers to the ability to remember or utilize already acquired knowledge or skills. It is a function of the value and relevance of the learned material to the learner (Onyehalu 1989) Retention refers to skills or knowledge or competences a learner acquired and retained from a learning situation after forgetting has taken place. It is the capacity to remember something – knowledge, skills, habits, attitudes, or other responses initially acquired. In practical chemistry the acquisition of skill and the retention of such skills, may facilitate the learning of the new task and achievement.

To do well in WASSCE and GCE, chemistry requires effective teaching and learning of practical chemistry in well equipped laboratories, for practice aids achievement and retention. Since adequately furnished laboratories remain a dream in many secondary schools, it becomes imperative that alternative ways of meeting the needs of practical work must be embarked upon. One of such ways or solution could be a cost reducing strategy. Cost reducing strategy could be any of the following: small-scale experiment, improvisation, precautionary measures in application of expendables, possible recycling of chemicals and demonstration.   All these are geared towards reducing the amount of money that would have been needed for materials for conducting practical chemistry. Akwabali (1984) viewed cost reducing strategy as involving improvisation, role simulation, conscious application of locally available materials, ability to economize quantity of reagents, use of recycling procedure, ability to minimise the contamination of reagents, repairs and maintenance of equipment and the extent to which valuable experimental products are made and stored ready for the market and the ability to use small scale experiment.

Of all these, the study is focusing on small-scale experiment. Small-scale is chosen for this study because laboratory materials are inadequate in many secondary school laboratories and it allows the use of small quantity chemicals for experiments. Small-scale experiment (SSE) entails miniaturizing the quantity of chemicals required for a particular experiment. An example of SSE is reducing the concentration and volumes of chemicals or grams of solid laboratory materials required for volumetric analysis and yet getting the same result as though the conventional quantities of the materials were used. In volumetric or quantitative analysis (acid base titration) practical lesson is conventionally done with pipette of 20 or 25cm3 for base and burette of 50cm3 for acid. Conventional approach to teaching practical chemistry lessons demands that at least 100cm3 of acid and 50cm3 of the base will be used for the experiment. This quantity when not available, demonstration by a teacher or a leader of a group is normally employed by a resourceful teacher. Demonstration is a display showing how to do something. Demonstration in practical chemistry means to show or prove something clearly and convincingly by one person, either the teacher or a leader to others or a group. As the teacher or a leader of a group demonstrates a particular skill, students or others observe. Since the entire chemistry students do not conduct the practical, the expendables they would have used are saved. Demonstration therefore, is a cost reducing strategy.  Skills are rarely learnt by mere observation. Demonstration in chemistry or science is one of the conventional approaches to teaching chemistry or science.

In SSE, to reduce cost, syringes or micro burette and pipette of 5 to 10cm3 could be used for both acid and base and a drop of an indicator will be added instead of the normal two drops. The small quantity of chemicals used in SSE affords every student the opportunity to practice with his/her hands, unlike in demonstration where only one person practices. With the above description of apparatus about 40cm3 of the acid and 15cm3 of the base will be saved. Syringes may not present full opportunity for students to acquire manipulative skills associated with the use of standard equipment but it will expose the students to properties of expendables used and some skills which are useful in conducting the actual conventional practical lessons. The scarcity of educational materials has influence on the overall performance of the students that suffer the scarcity. Mbakwe (1982) held the same view and blamed the scarcity of the educational facilities on the planners who would not see why the running of science education should cost more than those of other disciplines. If the subject chemistry must be taught effectively, a lot of practical lessons are required. To meet with the demands of effective teaching and positive achievements in the period of insufficiency of laboratory materials, application of small-scale experiment, (reduction of mass/volume and concentration of chemicals), which can help alleviate the problem of insufficient chemicals in the chemistry laboratories, becomes necessary.  It is easier to augment the practical knowledge and skills acquired from the use of SSE with those of conventional approach which mainly come few weeks to the external exterminations instead of beginning to expose students to chemistry practical lessons when it is too late for in-depth understanding of chemistry concepts and acquisition of practical skills.

One thing about this small-scale approach/experiment is that cost is actually reduced but the result of the experiment remains unchanged. This study did not consider the result of experiments which remain the same with the same chemicals but the examination of the reduction in volume and size of laboratory materials on students’ achievement and retention in chemistry Therefore, it may be adopted in our secondary schools now that the scarcity of materials for experiment is high, but will the cost reducing teaching strategy affect students’ achievement and retention in practical chemistry?. This is the question this study sets out to answer.

Statement of the Problem

Practical aspect of chemistry demands the use of equipment and chemicals or expendables to make the teaching and learning of chemistry effective. Some of these things are inadequate. Effective teaching and learning of chemistry require learners to go through practical experiences where they will be exposed to the concrete experiences of the qualities of matter, reactions and products of some materials. The experiments usually done in schools laboratories require that both teachers and pupils or students expend consumables and utilize school equipment. Most of the consumables like tetraoxosulphate (VI) acid, potassium hydroxide, silver trioxonitrate (v) salt and lots more are very expensive. The result is that many school laboratories do not have enough of the required materials for meaningful practical work. Sometime the chemistry teachers are forced to only demonstrate the required skills in order to economize the expendables. Of course, demonstration while having some merit cannot adequately replace the experience students have when performing the experiments themselves.

To still have students go through the practical experience required for effective learning and teaching of chemistry, a strategy, small- scale experiment, which is cost reductive may be adopted. According to Oladimeji (1987) the scaling down of the molarities of reactants (small scale experiment) helped to preserve or save a reasonable quantity of the samples. But will the use of small-scale experiment as a cost reducing teaching strategy affect students’ level of achievement and retention when compared with demonstration?

Purpose of the Study

The purpose of this study was to empirically determine the examination of the SSE on senior secondary students’ achievement and retention in practical chemistry.  Specifically, the objectives of the study were to:

  1. Compare the mean achievement score of SS II students taught using small-scale experiment (SSE) with the mean score of those taught with demonstration method (DM) in chemistry.
  2. Ascertain the extent to which chemistry achievement scores obtained by students depend on their ability levels when taught with SSE.
  3. Compare the retention scores of SS II students when taught chemistry with SSE and DM.
  4. Examine to what extent the chemistry retention scores obtained by the students taught with SSE depend on their ability levels.
  5. Determine the interaction examination of the teaching methods (SSE and DM) and ability levels on students’ achievement in chemistry and
  6. Ascertain the interaction examination of the teaching methods (SSE and DM) and ability levels on students’ retention in chemistry.

Significance of the Study


The findings of this study may contribute to ensuring effective chemistry teaching and learning through application of small-scale experiment, if it is found effective.  As SSE allows the used of small quantity of chemicals, practical lessons can go on when chemicals are in short supply. The study serves to open new ways of responding to the challenges of teaching and learning chemistry since the strategy will incorporate principles of learning and effective teaching. Where the cost reducing teaching strategy proves to be effective, students, teachers, policy makers and curriculum developers may benefit.

Students have the opportunity of being exposed to practical chemistry experiences with the application of SSE. Teaching of concepts, which could have been left because of large quantity of materials required for conventional chemistry practical lessons, could now be practiced using SSE. With this the objectives of chemistry are likely to be achieved and students’ achievement and retention enhanced. With SSE practical chemistry lessons are conducted when expendables are inadequate, students who give theoretical answers to practical questions due to poor practical exposure (Chief examiners’ reports, (CER) 2003), could attempt practical questions correctly, having been exposed to sufficient practical lessons using SSE. Students having been exposed to practical experiences in due time, may no longer muddle up tests and use wrong reagents. (CER 2003)

If the chemistry teachers adopt the use of SSE, the scheme of work could be covered in due time and the excess work load they usually experience as external examination draws near will be reduced. In addition, teachers’ effectiveness may be enhanced with the use of small scale experiment.

This study revealed that students’ ability level is a significant factor in affecting their achievement and retention in practical chemistry. This may help chemistry teachers to place students according to their ability levels where materials and lessons prepared according to students abilities will be used in teaching them.

School administrators may also benefit from the findings of this study if SSE is adopted widely. This is possible because the use of SSE reduces cost of teaching and learning chemistry and subsequently reduces the cost managing the schools.

The findings of this research work will assist the policy makers and curriculum planners in developing course of study for pre-service chemistry teachers seeing that SSE is applicable when laboratory materials are inadequate.

Scope of the Study

The cost reducing approach to teaching and learning of chemistry used in this study is small-scale experiment.  It was used to teach SS II the content of practical chemistry, which was limited to quantitative, and qualitative analyses. The senior secondary SS II students were chosen for the study because the qualitative and quantitative analyses are within their scheme of work. The achievement and retention scores and ability levels of SSII chemistry students were also considered using SSI annual results. The results were shown to chemistry teachers for confirmation. For quantitative analysis, NaOH and HCl of 0.05M concentrations were used.

The qualitative analysis was limited to testing for the presence of ions in FeSO4 and Fe2 (SO4)3 using NaOH, HCl and BaCl2 solutions.

Research Questions

The under listed research question guided the study.

  1. What is the mean achievement score of SSII students taught practical chemistry using small-scale experiment (SSE) and demonstration method (DM)?
  2. What would be the level of chemistry achievement scores obtained by students in relation to their ability levels when taught with SSE?
  3. What is the mean retention score of SSII students in chemistry taught practical chemistry using SSE and DM?
  4. How is the level of practical chemistry retention score obtained by the students related to their ability levels when taught practical chemistry with SSE?
  5. How does the interactive examination of the methods of teaching (SSE and DM) and ability level affect the students’ achievement in chemistry?
  6. What is the interaction examination of the methods of teaching (SSE and DM) and ability levels on students’ retention in chemistry?


The hypotheses were tested at 0.05 level of significance.

Ho1:   There is no significance difference in the mean achievement scores of students taught practical chemistry using SSE and DM.

Ho2:   The mean achievement score of SS II students of different ability levels would not differ significantly when taught practical chemistry using SSE.

Ho3:   There is no significance difference in the mean retention

score of students taught chemistry using SSE and those taught using DM.

Ho4:   The mean retention score of students of different abilities would not significantly depend on the teaching strategies, SSE.

Ho5:   The interaction examination of teaching methods (SSE and DM) and ability level on students’ achievement in chemistry is not significant.

Ho6:   There is no significant interaction examination of   teaching methods (SSE and DM) and ability levels on students’ retention in chemistry


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