Papers by Shadreck Mandina
This study evaluated the implementation of the Advanced level chemistry curriculum in Gweru distr... more This study evaluated the implementation of the Advanced level chemistry curriculum in Gweru district secondary schools in Zimbabwe. To guide this study seven research questions were raised and answered. The study employed a descriptive survey design and three instruments were used to collect data from 6 secondary schools selected from 12 schools in the district using the Probability Proportionate to Size (PPS) sampling technique. Six (6) school heads, 10 chemistry teachers and 130 students participated in the study. The instruments used for data collection were a questionnaire, interviews and personal observations. The study established that the important factors that limit the quality of chemistry teaching and learning include overloaded curriculum content and inadequate time for teaching chemistry; inadequate resources, apparatus, equipment and consumables. Insufficient funding of science, lack of support staff and ineffective teaching methodologies further limit the quality of ch...
European Journal of Science and Mathematics Education, 2015
This study investigated primary school teachers’ perceptions of the barriers and challenges preve... more This study investigated primary school teachers’ perceptions of the barriers and challenges preventing them from integrating ICTs in the environmental science classroom. The study adopted a qualitative research approach that is in line with the phenomenological perspective as it sought to acquire knowledge through understanding the direct experience of others by engaging with participants through semi structured interviews and classroom observations. The participants of this study were 14 7th grade primary school teachers purposively sampled based on based on qualities like class level, working experience and gender. According to the findings of the study primary school environmental science teachers are not yet ready to integrate ICTs into their classrooms due to a number of obstacles that include unavailability of infrastructure, equipment and web based resources in the classrooms. Teachers also lacked competence, in service training and technical support, as well as technological...
African Journal of Pure and Applied Chemistry, 2014
The increased use of chromium (Cr) in several anthropogenic activities has led to the subsequent ... more The increased use of chromium (Cr) in several anthropogenic activities has led to the subsequent soil, surface water and ground water contamination. It has wide applications in the dyes, stainless steel, leather tanning, electroplating of chrome, and wood preservatives industries. Chromium exists in the environment in several diverse forms such as Cr(0), Cr(III) and Cr(VI) species. Cr toxicity depends on its valence state. Cr(VI) which is regarded as being highly mobile is toxic, while Cr(III) is less mobile and less toxic. Cr(VI) being more mobile in soil, more toxic and a stronger oxidant penetrates more readily into the cell membranes than the trivalent form. Chromium does not bioaccumulate in plants and animals therefore high levels of chromium in the environment are highly toxic to plants and animals. Chromium toxicity in human beings is expressed in liver and kidney damage as well as skin lesions or rashes. Symptoms of chromium toxicity in plants include alterations in the see...
Asian Social Science, 2012
The purpose of this study was to examine the perceptions among junior secondary science students ... more The purpose of this study was to examine the perceptions among junior secondary science students from Gweru Urban secondary schools in Zimbabwe towards science teachers' teaching quality and effectiveness. This qualitative study approached and interviewed Form 2 students from 10 different schools in Gweru urban. The results show that three key dimensions of science teacher quality and effectiveness emerged: teacher's scientific knowledge, teacher’s pedagogical skills and teacher's social competence. Findings suggest that the teachers can promote and enhance teaching effectiveness by applying a positive student approach, understanding students’ learning difficulties, acknowledging the individual student, being someone the students can trust, being able to organise and teach in interesting and flexible ways, using good teaching methods, their ability to plan and structure the content and the use of practical investigative science in the classroom. Student perspectives, how...
The purpose of the study was to provide a view of school heads on what can be done to promote an ... more The purpose of the study was to provide a view of school heads on what can be done to promote an environment that can assure quality and accountability in education. The study was qualitative in nature and adopted the multiple case study design. The study was conducted with six secondary school heads that were purposively sampled from a group of forty school heads. Data was collected using observations and interviews which were digitally audio recorded and then transcribed verbatim. Data was analyzed through coding, categorizing and identification of emerging themes. The findings from the study indicate that school heads can foster a conducive environment for assuring quality and accountability in education by maintaining positive relationships with members of staff, providing training to staff members, and providing material and financial resources as well as promoting professional growth and development of their teachers. School heads should also form partnerships with the private...
The study sought to find out difficulties encountered by high school chemistry students when solv... more The study sought to find out difficulties encountered by high school chemistry students when solving stoichiometric problems and how these could be overcome by using a problemsolving approach. The study adopted a quasi-experimental design. 485 participants drawn from 8 highs schools in a local education district in Zimbabwe participated in the study. A validated stoichiometry achievement test was used to collect data at pre-test and post-test stages. The researchers also prepared a difficulty identification index to analyse the difficulties encountered by students. Quantitative data was analysed using inferential statistics and ANCOVA. From the findings, the difficulties identified were lack of understanding of the mole concept, inability to balance chemical equations, use of inconsistent stoichiometric relationships, identifying the limiting reagent, determination of theoretical yields and identification of substances in excess. The study also found that the use of problem-solving instruction as effective in remedying the identified difficulties in comparison to the conventional lecture method. It was strongly recommended that chemistry educators should analyse and understand student difficulties if they are to assist the learners to become confident and efficient problem solvers. Furthermore chemistry educators should implement the problem-solving pedagogical technique as a means of addressing the difficulties students have in stoichiometry problem-solving.
Advances in Social Sciences Research Journal, 2015
This study set out to find out the perceptions of teachers and learners of Principles of Accounts... more This study set out to find out the perceptions of teachers and learners of Principles of Accounts at ordinary (“O”) level in Masvingo Urban District secondary schools in Masvingo Province in Zimbabwe regarding streaming of learners and how such perceptions impact on the teaching and learning of the subject. The descriptive survey design was adopted for this study because it enabled the researchers to study a limited number of cases with a view of drawing up conclusions about the generality of the whole group under study. The estimated population of the study was eight (8) “O” level Principles of Accounts teachers, eight hundred and forty (840) “O” level Principles of Accounts students in four (4) schools in Masvingo Urban District and two (2) education inspectors of commercial subjects in the same district. A sample of one hundred and eight (108) learners and six (6) teachers from three (3) schools and the two education inspectors was used in the study. Data were collected through t...
The non-participation of girls in advanced mathematics has become a concern over a number of year... more The non-participation of girls in advanced mathematics has become a concern over a number of years. This study sought to find ways of increasing female participation in Mathematics at advanced level based on an understanding of the constraining factors to female participation in mathematics. The descriptive survey research design was adopted in this study in which questionnaires, interviews and observations were used as data collection instruments. Questionnaires were completed by ninety nine female students (sixty ‘O’ levels and thirty nine ‘A’ levels) and nine mathematics teachers. Interviews were conducted with three mathematics teachers, 10 ‘A’ level female students who were not taking mathematics and twenty ‘O’ level female students. Classroom observations were also conducted in six Mathematics lessons. Each lesson lasted for forty minutes. The results of the study have revealed the following factors as limiting female participation in mathematics: perceived difficulty of the s...
IOSR Journal of Environmental Science, Toxicology and Food Technology, 2013
This study assessed chromium pollution in soils, plants, water and slag from a ferrochrome smelti... more This study assessed chromium pollution in soils, plants, water and slag from a ferrochrome smelting plant in Gweru, Zimbabwe. Speciation of chromium in plant leaves, soil and slag samples was carried out by selective leaching of Cr (VI) using a sodium carbonate leaching procedure prior to the spectrophotometric determination of Cr (VI). Total Cr and Cr (III) concentration in the samples were analyzed by Flame Atomic Absorption Spectroscopy following aqua regia and oxidative acid digestion. The average concentration of Cr (VI) in soil (1.0301 ± 0.0854) µgg -1 and plant (0.3372 ± 0.0168) µgg -1 samples were higher relative to control samples with the contamination factors of 3.2 and 3, respectively. Leaching of hexavalent Cr indicated its poor solubility in water (0.00141 µgg -1 ).
The study sought to find out the difficulties encountered by high school chemistry students when ... more The study sought to find out the difficulties encountered by high school chemistry students when solving stoichiometric problems. The study adopted a quasi-experimental design. 525participants drawn from 8 highs schools in a local education district in Zimbabwe participated in the study. A validate stoichiometry achievement test was used to collect data at pre-test and post-test stages. The researchers also prepared a difficulty identification index to analyse the difficulties encountered by the students. Quantitative data were analysed using descriptive statistics. From the findings, six major difficulties identified were lack of understanding of the mole concept, inability to balance chemical equations, use of inconsistent stoichiometric relationships, identifying the limiting reagent, determination of theoretical yields and identification of substances in excess. The study also found that the use of problem-solving instruction was effective in remedying the identified difficultie...
Cypriot Journal of Educational Sciences, Dec 26, 2018
The study investigated the effect of a Target-Task Approach on the performance of advanced level ... more The study investigated the effect of a Target-Task Approach on the performance of advanced level chemistry students in electrochemistry. The study adopted the quasi-experimental research design. Data were obtained from two advanced level chemistry classes from two high schools in Gweru, Zimbabwe. One of the two classes was assigned to be the experimental group, while the other class acted as the control group. The experimental group was taught electrochemistry using Target-Task Approach, while the conventional method was used to teach the control group. Analysis of covariance was used to analyse all the data generated from the study. The hypotheses formulated were all tested at the 5% level of significance. The results revealed that the difference in performance between the experimental and control group was statistically significant. The findings further show that the use of the Target-Task Approach greatly enhance the performance of low and medium scoring level students.
EURASIA Journal of Mathematics, Science and Technology Education
The study investigated the comparative effects of Selvaratnam, & Fraser (1982) and Ashmore et al.... more The study investigated the comparative effects of Selvaratnam, & Fraser (1982) and Ashmore et al. (1979) problem-solving instructional strategies on Advanced Level students' achievement in Stoichiometry. The quasi-experimental design with a nonequivalent comparison group consisting of pre-and post-test measures was utilized in the study. The participants were 525 Advanced level chemistry learners drawn from 8 high schools from Gweru district. Data were collected using standardized achievement Tests in stoichiometry. The problem-solving instruction was implemented in four experimental schools while the remaining four control schools were taught using the conventional lecture method. Analysis of Covariance (ANCOVA) was used to analyze data. The findings indicated a statistical significant difference in the performance of students taught using the two problem-solving strategies and those taught using the conventional method. The Scheffe's post-hoc test indicated that students taught using the Ashmore et al. (1979) problem-solving instructional strategy performed significantly better than those taught with the Selvaratnam & Fraser problem-solving strategy. Furthermore, it was also found that the performance of students in the experimental group was not influenced by gender. Chemistry teachers are therefore strongly recommended to use problem-solving instructional strategies in their classes to improve the abilities of learners in solving stoichiometry problems.
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Papers by Shadreck Mandina