The effects of teachers’ professional and pedagogical competencies on implementing cooperative learning and enhancing students’ learning engagement and outcomes in science: Practices and changes

Abstract The study evaluated the effects of teachers’ professional and pedagogical competencies on implementing cooperative learning method and enhancing students’ learning engagement and outcomes in science. The study employed randomized controlled trials method. The pretest-posttest data were analyzed by using two-tailed t-test and ANCOVA to either reject or not reject the formulated hypotheses at the p 0.05 level of significance. The findings indicated that the implementation of cooperative learning method resulted in students’ authentic learning engagement and higher academic achievements in science compared to individualistic lecture method where the differences between the baseline, mid-line and end-line showed significant increase because of teachers’ professional learning practices to develop and update competencies and skills. Proper utilization of cooperative learning in classrooms helps to accommodate heterogeneity of students from diverse background ahead of ensuring learning engagement. The natural science teachers exposed to cooperative learning method developed better professional competencies and skills like content-knowledge, pedagogical skills, beliefs and attitudes compared to those who were not exposed to it. Thus, there were direct relationships between utilization of cooperative learning method and students’ learning engagement and outcomes in science. The finding summarized that teachers’ professional learning interventions improve implementation of cooperative learning method in classrooms. Thus, cooperative learning method persuades students’ learning collaboratively and individually to promote higher order thinking, learning and responsive creativity. Teachers’ continuous professional development practices should be implemented to improve their professional and pedagogical competencies and students’ interdependence, individualistic accountability, communication skills, group processing skills and students’ learning engagement.


PUBLIC INTEREST STATEMENT
The 21st century classroom requires the 21st century teachers and students. Similarly, in Ethiopia, both teachers and students are equally important to implement the curriculum in classrooms. Effective utilization of cooperative learning method in classrooms is important to accommodate heterogeneity of students from diverse socio-cultural background ahead of ensuring their learning engagement. Meanwhile, teachers are expected to be midwives of society rather than a textbook specialist in white coat. Assisting teachers to develop and update their professional and pedagogical competencies and skills are friendly scenarios to improve quality of instructional practices in classrooms and student' learning engagement and outcomes. The paradigm shift from lecture method to cooperative learning method is essential to make students take the position of constructivists through developing positive interdependence, selfconfidence, communication and information processing skills and critical thinking because of higher order thinking and learning practices. Therefore, this study implies the requirements of strengthening collaborative, communicative, critical thinking, innovation and creativity among teachers to prepare students to next academic level.
end-line showed significant increase because of teachers' professional learning practices to develop and update competencies and skills. Proper utilization of cooperative learning in classrooms helps to accommodate heterogeneity of students from diverse background ahead of ensuring learning engagement. The natural science teachers exposed to cooperative learning method developed better professional competencies and skills like content-knowledge, pedagogical skills, beliefs and attitudes compared to those who were not exposed to it. Thus, there were direct relationships between utilization of cooperative learning method and students' learning engagement and outcomes in science. The finding summarized that teachers' professional learning interventions improve implementation of cooperative learning method in classrooms. Thus, cooperative learning method persuades students' learning collaboratively and individually to promote higher order thinking, learning and responsive creativity. Teachers' continuous professional development practices should be implemented to improve their professional and pedagogical competencies and students' interdependence, individualistic accountability, communication skills, group processing skills and students' learning engagement.

Background of the study
The 21 st century classroom instruction is based on the 3ʹP' pedagogical principles like professionalization, participation and productivity (UNESCO, 2005) which underlines that great professional development makes great pedagogues through improving how teachers teach, what teachers teach and how pupils' learn from professional practices (Husbands & Pearce, 2012;UNESCO, 2005). A professional teacher has a responsibility to fulfill students' learning needs and gives quality and relevant instructional services without excluding students (Tatto, 2021). Furthermore, teachers invest time and energy to empower learners to take control of their own learning process through provisions of effective scaffolding for students using modeling, shared practice, guided practice, independent practice, and student's application approaches (Sharratt, 2019). Specifically, cooperative learning is one of the most remarkable and fertile areas of theory, research, and practice in education. It exists when students work together to accomplish shared learning goals (D. W Johnson et al., 2000). Evidently, different theoretical perspectives like social interdependence, cognitive-development, and behavioral learning provide clear rationales as to why cooperative efforts are essential for maximizing learning and ensuring healthy cognitive and social development as well as many other important instructional outcomes. Research studies demonstrated that cooperative practices result in higher individual achievement than do competitive or individualistic efforts of learning (D. W Johnson et al., 2000). Thus, there are relationships among individual and group members' actions and interactions to achieve the intended learning destination in cooperative learning method. Similarly, cooperative learning aims at helping students to learning with and from each other, sets-up different learning paths that provide tailored instruction and exercise-based upon students' characteristics (Tomlinson, 2015). Yet, cooperative learning method often implemented in the classrooms via structural differentiation where within class ability grouping is used by segregating students into groups on the basis of prior achievement (Deunk et al., 2018). These traditional practices remain rooted in deficit thinking about students' potential and ability, and undermine the provisions of differentiated teaching and learning for all students in heterogeneous settings. However, adapting and contextualizing best educational theories and practices into the classrooms improve teachers' professional practices and students' learning outcomes (Girma et al., 2021). For successful implementation of specialized teaching and active learning styles of diverse learners, science teachers consider the learners' motives, abilities, interests and learning styles (Mest, 2016).
Although there is no single view of learning or teaching dominated what might be called good teaching (Kember, 1997), teaching method is a means by which teachers attempt to impart the designed learning experiences that the learners understand and bring about behavioral changes and includes setting the objectives, selecting the contents and procedures to best achieve the objectives and evaluating the whole process (Firdissa, 2005). For that reason, deep learning is associated with meaningful activities in a setting that include collaborative peer learning; and replacing most lectures by a small group learning that ended in a mini-conference (Tsaushu & Tal, 2017). While there are various methods of teaching that teachers can use, the central focus and purpose are enhancing students' performances (Firdissa, 2005) even though there are tensions and relationships between them. Thus, even if there are tensions and relationships between them, educators teaching styles can be conceptualized from the points of teacher-centered to student-centered teaching spectrum.
The world society today needs young people who are flexible, creative and proactive to solve problems, make decisions, think critically, communicate ideas and work efficiently within teams and groups (UNESCO, 2005). The epistemological assumption is no longer enough to succeed in complex, fluid and rapidly evolving postmodern world in which we live. Meanwhile, the emergence of a global movement that calls for a new model of learning for the 21st century has been argued that formal education must be transformed to enable new forms of learning to tackle complex global challenges. In high performing schools, all members of the school community both individually and collectively hold themselves accountable to address students' diverse needs and successes (Girma & Abraham, 2019). Thus, the science curricula in Ethiopia aimed to empower young generations to develop their potential as individuals and make informed and responsible decisions for living and working in the 21 st century.
Cooperative learning method is theoretically based on the work of psychologists like Levi Vygotsky who proposed that children actively construct knowledge in a social context (Conway, 1997). The CLM as one of the learner-centered strategies is the deliberate instructional use of heterogeneous small groups of students who work together to maximize each other's learning (Igboanugo, 2013). There are four criteria for mixed group formation (MoE, 2014). This includes arbitrary grouping, ability grouping, mixed grouping and compatibility grouping. The groups are formed on the bases of these four criteria and are dynamic throughout the academic years. This indicates that it promotes learners teamwork and creates something new rather than simply taking readymade information. Students develop more positive attitudes to science when they work together cooperatively than when they work alone (Panitz, 2008). A lot has been done to improve science teaching in primary and secondary schools in different countries despite that students continue to perform poorly in science subjects (Samba & Eriba, 2012). This situation has created the need for more effective teaching methods to enhance the academic performance of students in natural science disciplines. Hence, the working out frameworks used in this study was the systems theory in education which depicts the teaching and learning process as having inputs that interact to produce outputs (Shavelson, 1987). In the context of instructional process, the learner is the input which undergoes desirable changes through the teaching-learning process (Ayot & Patel, 1992). Therefore, the performance of learners and their academic achievements are educational outputs and outcomes, respectively.
As perspectives are philosophical orientations to knowledge and learning, the responsibility of being a teacher is important to discourse that the transmission and developmental perspectives represent a legitimate view of teaching when enacted appropriately. Throughout the process, preconceived notions of good teaching are challenged as educators are asked to consider what teaching means to them. A researcher's long professional experience as subject methodology and general method of teaching or pedagogues instructor assisted him to recognize supremacy of positivists' over constructivists' standpoints in science instructional system. This hegemony caused complications of implementing the hands-on teaching strategies in science to enhance students' competencies. Academic achievement of students in biology at the secondary school level nationally has been low and one factor for low achievement is the teaching methods adopted by a teacher. A learner-centered teaching approach is expected to promote high order thinking, learning and academic achievement as compared to teacher-centered approach (Girma & Abraham, 2019;UNESCO, 2005). This promotes deep learning in comparison to surface coverage approach of learning.
The CLM is an active education strategy with small groups in order that the students develop their learning potential (Kolawole, 2007). Although some scholars consider it as a political language, the cooperative learning method actively involves learners in the teaching-learning process thereby promoting learning and higher academic achievement than a teacher-centered approach (Agashe, 2004). Thus, rethinking pedagogy of the 21 st century is fundamental to identify the new competencies that today's learners need to develop and learn using their minds until they reach to the zone of proximal development. Besides, the cooperative learning method has positive effects on ranges of student outcomes including academic achievement and social skills development (Ferrer, 2004;Kolawole, 2007). However, implementation of CLM does not occur within a vacuum but rather strongly influenced by school reforms and initiatives that occur within a shifting landscape of socio-political priorities and policies at multiple levels (Han & Weiss, 2005). This shows that when critical factors are managed, there are direct relationships between effective utilization of CLM and students' learning outcomes under optimum condition. Primary schools' teachers in Ethiopia have got the propensities to exercise active learning methods (e.g., CLM, brain storming, pyramiding, group discussion) and assessment for learning during their pre-service and in-service program, and actual working times in schools via training and experience sharing practices (Girma & Abraham, 2019). However, the schools cannot improve classroom practices and students' learning outcomes. As knowledge brokers, teachers transfer knowledge from those who possess it to those who need to have it (Jusinki, Margaret, 2021). Professional teachers have the responsibilities to fulfill students' learning needs and give quality instructional services without any students' exception (Tatto, 2021), and they use cooperative learning strategies in classroom to accommodate heterogeneity of students (Smets et al., 2020). Hence, teachers are represented as midwives of society without whom the future of society will be malformed (Goodson & Hargreaves, 2002) and their professional and pedagogical competencies in the classroom practices are unquestionably important.

Theoretical framework of the study
There is no single child is fully capable of performing all of the tasks required by a particular assignment or project because students who are working cooperatively share knowledge and learn from each other (Mary, 2003). The implementation of cooperative learning method in the classrooms requires the following responsibilities to enhance students learning engagement and improving academic achievement (Girma & Dawit, 2022;D. W. Johnson et al., 1993). These are teachers' professional and pedagogical competencies and skills, and students' skills like (1). Positive interdependence -is important for the group to work toward the goal(s) set by the teachers. Ideally, these roles are unique for each member of the group and it is vital that each member perform their assigned task. (2). Individual accountability -teachers assess the academic learning or the attainment of social skills by formal or informal methods using subjective or objective measuring instruments. Generally, this is a test, homework, or observation of social skills demonstrated in a group setting. (3). Social skills-the participants' abilities to share materials and workspace. Participants demonstrate consideration for others by keeping their voices at a reasonable level. (4). Communication skills-Participants demonstrate the ability to discuss topics, to disagree without causing arguments, and to resolve conflicts peacefully. Participants use conflict resolution strategies as necessary. (5). Group processing skills-The oral or written procedure allows the students to tell the teacher how well the groups worked together or report any problems. The teacher might discuss the completed cooperative activity with the students to gain their input that way, or ask for the information in written format. Allowing students to write their comments permits confidentiality. Teachers might use information gained from group processing when forming groups for future projects, grading, or addressing deficiencies in acceptable social skill demonstration.
The theoretical framework of the study summarizes that teachers' professional and pedagogical competencies, and students' positive interdependence, individual accountability, social skills, communication skills and group processing possess direct relationships students' learning engagement and academic achievement in science classrooms (Mary, 2003). In addition, teachers' and students' characteristics and school inputs are extraneous variables. Thus, four trained teachers participated as intervening groups and four teachers participated as control groups. The STAD model was adapted and contextualized by assuming that it is the simplest model of CLM (Arends, 1997;Slavin, 1995). Hence, the researchers used the STAD model in the evaluation of application of cooperative learning method in the intervening school.

Rationales of the problem
The experience of a researcher demonstrated that although there were many efforts to implement a variety of active learning methods in classrooms in general and cooperative learning method in particular, it did not improve students' learning engagements and outcomes. However, teachers' participation in collaborative learning and reflective inquiry has potential effects to improve their professional competencies (Sims & Fletcher-Wood, 2020). In addition, the effects of school policies and procedures on the allocation of resources affect the status curriculum implementation using equitable pedagogical strategies to address diversified needs of learners (Girma, 2022a). This influences the delivery of instruction to diversified students using pragmatic cooperative learning method. The local empirical studies conducted at macro and micro-levels indicated that active learning strategies, therefore, were not practiced and brought the expected outcomes due to lack of awareness, understandings and unable to manage teaching perspectives and teaching methods, political ideologies, large class size, poor perceptions, lack of knowledge and skills, willingness and other inertia (Girma & Abraham, 2019;Girma & Feyera, 2019;Teshager, 2009). These studies revealed that the practices of active learning methods were downgraded because of perplexing impeding dynamics in schools mainly due to poor perceptions and low professional competencies of teachers. In addition, teachers' opportunities of getting appropriate training and experience sharing practices with application of equitable pedagogical strategies like active learning methods were limited (Girma & Dawit, 2022). Hence, the local studies were too general to address implementation of CLM and were not put into actions to improve an ongoing teaching-learning process.
Teachers' continuous professional development activities have potential benefits regarding the implementation of differentiated pedagogical practices, and improvement of classroom instruction and student engagement (Girma & Dawit, 2022). This intervention indicated a promise that if CLM is implemented effectively, the likelihood of positive results is quite high. With this premise, the results of meta-analysis provided evidences that show all CLM have produced higher achievement than competitive and individualistic learning methods. The more conceptual approaches to CLM may produce higher achievement than direct methods of instruction. From the highlighted and concealed gaps, the interventions of CLM helped the learners to hand on activities to headway their learning outcomes. However, in the Ethiopian context, the implementation of CLM was never practiced effectively beyond its theoretical understanding as a method of teaching. However, if the educative measures are not occurred in time to solve the shortcomings, the quality of instructional system will negatively affect education system and impedes the production of quality learners as schools are capacity-building centers. Thus, the study evaluated the effects of teachers' professional and pedagogical competencies on implementation of cooperative learning method and enhancement of students' learning engagement and outcomes in science (biology, chemistry, physics and mathematics).

Objectives of the study
The main purpose of the study was evaluating the effects of teachers' professional and pedagogical competencies on implementation of cooperative learning method and enhancement of students' learning engagement and outcomes in science (biology, chemistry, physics and mathematics) in classrooms. More specifically the study helps to: (1) Evaluate the effects of teachers' professional and pedagogical competencies on implementation of cooperative learning method in classrooms and students' learning engagement and outcomes.
(2) Compare and contrast the gender-wise mean achievement scores of students in natural science of those who are exposed to CLM intervention in classrooms.
(3) Evaluate the posttests mean achievement scores of students in natural science who are exposed to and not exposed to successive posttest interventions.
(4) Compare and contrast the natural science teachers who are exposed to the utilization of CLM to develop better professional and pedagogical skills than those who are utilizing LM in classrooms.

Hypotheses of the study
To evaluate the effect of primary school teachers' professional competencies and pedagogical skills of implementing cooperative learning in classrooms and enhancing students' learning achievement in science, the following alternative directional and null hypotheses were formulated. These are: Ha 1 : Students who are exposed to CLM interventions achieve higher mean achievements in natural sciences than those who are not exposed to CLM.
Ha 2 : Students who are exposed to CLM interventions achieve higher mean achievement in natural sciences in different cognitive and psycho-motor levels than those who are not exposed to interventions.
Ho 3 : There is no statistically significant difference gender-wise in natural science mean achievement scores of students who are exposed to CLM interventions in classrooms.
Ho 4 : There is no statistically significant difference in post-tests in natural sciences means achievement of students who are exposed to and not exposed to successive postinterventions.
H O5 : Natural science teachers who are exposed to utilization of CLM develop better professional and pedagogical skills than those who are utilizing LM in classrooms.

Significance of the study
This study is helpful to demonstrate the effects of authentic teachers' professional competencies and pedagogical skills of using CLM in primary schools' classrooms. It is capable to find out possible strategies to augment academic performance and achievements of primary school students in natural science. Likewise, it helps to provide strategies to department heads, technicians, teachers, and students on how to improve their students' academic performance and achievements. The findings of this intervention further help the school management bodies to discuss on how to shift from LM to CLM to help learners construct their professional competencies such as knowledge, skills and dispositions on utilization of this new paradigm shift in science. In addition, it helps future researchers as a source of information.

Definition of operational terms
Natural science in this study context includes biology, chemistry, physics and mathematics subjects. Professional and pedagogical competencies are defined as the confirmed teachers' knowledge, skills, beliefs and attitudes required in the classroom. Likewise, professional learning is defined as teachers (professionals) active learning such as knowledge construction, skills and positive attitude development. Cooperative learning method is defined as a collegial learning method to ensure critical and higher order thinking of students learning. Student engagement is active participation of learners in their learning such as knowledge construction, skill development and positive attitudes, and beliefs whereas a student outcome is defined as the academic achievement of students as result of hard working collaboratively and individually.

Research methodology
In the application of CLM, intervention, randomized control trial method was used since a welldesigned RCT is seen as the gold standard for evidence-based educational practices and scientific research for measuring an intervention's impacts (Styles, 2009;Torgerson & Cocks, 2013). Randomized control trial method helps the researcher to test the hypotheses to reach valid conclusions between independent and dependent variables (White, 2012). The schools in which cooperative learning strategy and lecture method implemented were the intervening and control groups, respectively. The comparison between control and intervening groups show the reach or contact between implementer and recipients (Naylor et al., 2015) which was vital to ensure the effects of interventions on students' learning outcomes. Accordingly, the participants of the study were the implementers (natural science teachers and grade 7 students) to manage the treatment properly.

Sample size and sampling techniques
The sample size of each target population was determined by believing that the ideal sample size of a target population is large enough to be selected economically in terms of both time and complexity and small enough to be manageable and specific for analysis (Best and Kahn, 1989). Based on this logic, appropriate sample was taken to measure the efficacy and effectiveness of learning outcomes of interventions using the RCTs method. Table 1 shows that before the actual intervention was carried out, first trial intervention was conducted in one primary school. One section intervening (4 teachers and 47 grade 7 students), and one section control (4 teachers and 50 grade 7 students) schools were taught for four weeks.
After the four weeks instruction, the tests were prepared and administered to students to check the effect size, fidelity, feasibility and relevance of natural science achievement test in terms of the objectives, hypotheses, contents and modes of instructional delivery of grade 7 natural science instructions. This has helped the researcher on how to prepare NSAT adjacent to each intervention to check validity and reliability and to assure the adequacy of samples and their voluntarism to take the tests. Table 2 shows that a total of two primary schools were randomly assigned as treatment-on school and comparison school. Accordingly, the total participants of the actual trials were 600 grade 7 students and 8 natural science teachers drawn from two primary schools to teach intervening and control groups by using CLM and LM, respectively. One school was randomly assigned for the treatment group and one primary school for the control group. Similarly, four natural science teachers were linked to the intervening and four natural science teachers were linked to the control groups to implement CLM and LM, respectively. Besides, randomized control trials teachers should be linked to the class before randomization (Torgerson & Cocks, 2013). This helped the researcher to prevent bias of estimation of participants.
One primary school (Abdisa Aga) was the intervening school while one primary school (Abiyot Fire) was used as a control school. The intervening and control groups were those whose pretestaverage means below and above the median scores, respectively. Likewise, grade 7 students were selected thinking that CLM has been extended along grade levels and into school-wide disciplines as success for all (Slavin, 1995). This assures the welfare of CLM over competitive and individualistic LM in teaching natural science (biology, chemistry, physics and mathematics) in primary schools.

Data collection instrument
The instrument used for data collection was a natural science achievement test (NSAT) constructed by teachers and the researchers based on topics taught by the traditional lecture method for pretest, and after teaching intervening and control groups by CLM and traditional LM, respectively. The validation of NSAT was done by two experienced followed by a pilot test carried out after first trial on grade 7 students in none sample primary school.

Pilot testing and procedures of interventions
Ethics is a primary consideration in the research process and tends to relate closely to the data collection, reporting, and distribution of reports (Cresswell, 2012). The first trial intervention was carried out, and then, the actual interventions were followed. The evidences were collected on the bases of the permission and willingness of respondents. Finally, the respondents were thanked for their voluntarism to be participated in the interventions and give genuine responses.
The fidelity or adherence of implementer to the activities was evaluated based on necessary literature (Odom et al., 2010). At the beginning, four natural science teachers were identified and training was given for those who took the experimental groups on the application of instructional approach for one week while the other four teachers who took the control groups used the lecture method. A pretest was carried out before randomization and intervention. Then, school whose means below the median was assigned as intervening school and that whose average mean above the median was assigned as control school. Then, a pilot test was carried in Bowa primary school grade 7 students, and the reliability coefficient between pretest and post-test of NSAT was found to be [α = 0.858, N = 105]. It was rated above 0.800 and the preparation of NSAT and its external validity were accepted. This enabled the researchers and science teachers to prepare NSAT according to table of specification to address the cognitive, affective and psycho-motor domains of learning. Finally, consecutive interventions were made for 20 weeks followed by post-tests until the intervening and control schools approach to reach the predetermined end line (75).  Table 3 indicates that a pretest was carried out on the topics which were taught by the traditional lecture method under the influence of the school under investigation. The result indicates that the average mean of two schools under study was 55.25 whereas the median score was 54.5. Therefore, the school below the median school was assigned as the intervening school while that above the median score was the control school. The baseline pre-equivalence test set was 55.25, the mid-line was 65, and the end line was 75, at which the two primary schools were expected to reach the same level of means after 20 weeks interventions.

Data analysis
To evaluate the effect size of the interventions, average mean, standard deviation, two-tailed t-test, and ANCOVA were applied by using SPSS version 24. Average mean scores were used to categorize the experimental and control schools by using the median level. Two tailed t-tests and ANCOVA were used to compare the two mean scores of experimental and control schools genderwise across the groups, respectively.

Results and discussions of the study
The effects of teachers' professional and pedagogical competencies of implementing CLM on students' learning engagements and outcomes results were organized, analyzed and interpreted in line with the formulated hypotheses. Accordingly, the dosage of interventions and how to carry out the interventions were determined by the researcher on the bases of the suggestions provided in the literature (Moore et al., 2015). Based on this, five consecutive interventions were made for 20 weeks to evaluate the effects of CLM on students' learning engagement and outcomes through testing the formulated hypotheses. Table 4 shows that the supposed students' skills practicing CLM have positive correlation with teachers' professional commitment and their learning engagement and outcomes at p > .05 level of significance. Thus, the effects of all variables used in cooperative learning on students' learning engagement and outcomes were low. More specifically, they were tested as Ha 1 : Students who were exposed to CLM interventions achieve higher mean achievement scores in natural science tests (NSAT) than those who were not exposed to interventions.  Table 6 shows that students under intervening school those learned by CLM achieved an average mean of 71.59 with an achievement mean of 6.18 after three weeks instruction while students under control groups learned by lecture method achieved an average of 56.17 with mean achievement gains of 0.28 on the same topic. From the analysis, the test value [(295, 303), t (25) = 7.54, p > 0.05]. The means of the two groups show a statistically significant difference at the p 0.05 level. Therefore, the alternative directional hypothesis (Ha 1 ) was not rejected. This remarks that there were statistically significant differences in NSAT mean achievement gains of students learned by CLM than LM. This finding matches with the finding of Blase and Fixsen (2013) which stated that understanding what makes a difference particularly in a complex intervention helps to ensure the achievement of intended learning outcomes.
Ha 2 : Students who were exposed to CLM interventions achieve higher mean achievement scores in cognitive and psycho-motor levels than those who were not exposed to CLM. Table 7 indicates that students under intervening school those learned by cooperative learning CLM achieved an average mean of 78.96 with an achievement mean of 7.37 after three weeks instruction while students under control schools learned by lecture method achieved an average of 57.19 with mean achievement gains of 1.02 on the same topic. From the analysis, the test value [(295, 303), t (34) = 7.98, p > 0.05]. The means of the two groups showed a statistically significant difference at the p 0.05 level. This indicated that there were significant differences in NSAT on cognitive levels mean achievement gains of students learned by CLM and LM. Instructional process is suggested to be vital with the view of learning as a cognitive process takes place face-to-face among small heterogeneous groups and encourage their knowledge development activities (Girma & Abraham, 2019;Tsaushu & Tal, 2017). Table 8 summarizes that students under intervening school those learned by CLM achieved an average mean of 85.85 with an achievement mean of 6.89 four weeks instruction while students under control group learned by lecture method achieved an average of 57.01 with mean achievement gains of 0.84 on the same topic. From the analysis, the test value [(295, 303), t (28) = 9.71, p > 0.05]. The means of the two groups showed a statistically significant difference at p 0.05 level. Therefore, the alternative directional hypothesis (Ha 2 ) was not rejected. This remarks that there were significant differences in NSAT on psycho-motor levels mean achievement gains of students learned by CLM than LM in imitation, manipulation and precision levels of skills. This is maintained by the finding of Tsaushu and Tal (2017) which stated that deep learning is evidenced by the ways students reflect on how they organize and apply knowledge. Deep learning methods include cooperative learning method, micro-teaching, laboratory, panel discussion, field visit and project works (Girma & Abraham, 2019).
Ho 3 : There was no statistically significant difference gender-wise in mean achievement scores of natural science instruction students who were exposed to CLM interventions. Table 9 shows that male and female students belonged to the experimental schools were learned by cooperative learning method and achieved an average mean of 67.69 and 65.81 with an achievement mean of 12.14 and 10.26, respectively, after four weeks of instruction. From the analysis, [(155, 139), t (29) = 11.23, p > 0.05]. The means of the two groups showed significant differences at the p > 0.05 significant level. Therefore, the null hypothesis (Ho 3 ) was not rejected. This remarks that there was no statistically significant difference gender-wise in NSAT mean achievement gains of students learned by CLM.
Ho 4 : There was no statistically significant difference in post-tests in mean achievement scores of students who were exposed to and not exposed to successive post-interventions. Table 10 indicates that [F (2, 1197) = 519.430, p < 0. 05] was statistically significant difference. This was because 0.000 is less than 0.05 significant level set for the hypothesis. Hence, the null hypothesis (Ho 4 ) was rejected and rephrased. There was a statistically significant difference between the mean achievement scores of students taught using CLM and those taught using LM between groups and within groups. The effect size of the study was 0.566. For interpretation of effect size, Muijs (2004, p. 194) gives the following guidance: 0.0-0.1-weak effect, 0.1-0.3-modest effect, 0.3-0.5-moderate effect, > 0.5-strong effect. Accordingly, the effect size of the intervention (0.566) is greater than 0.500. i.e. it has strong effect size. Therefore, the incremental changes were observed on the practices of cooperative learning during the five consecutive interventions. In line with this, Naylor et al. (2015) suggested that adaptation is one dimension of intervention evaluation to measure changes achieved in educational programs.

Findings and discussions
The following findings were identified from this small-scale study: These are: (1) Although students' learning engagements and outcomes showed some progresses after each intervention of cooperative learning method in classrooms, students' academic interdependence, individualistic accountability, social skills, communication skills and group processing skills lacked potential strengths in their learning opportunities.
(2) The differences in the means of posttest and pretest occurred because of treatment effects in favor of posttests whose means were higher than those of pretest mean scores. These showed that there were statistically significant differences between performances of experimental group taught with cooperative learning interventions and the control group taught with LM. This finding is consistent with five essential components systemically structured into the learning process to make cooperative learning successful (D. W. Johnson et al., 1993); positive interdependence, face-to-face interaction, individual accountability, interpersonal and small group skills and group processing.
(3) CLM interventions produced positive effects on students' learning engagement and academic achievement in experimental school used for the study. It enhanced higher academic achievement of students in natural science at knowledge, comprehension and application levels compared to lecture method. This finding is consistent with the findings of Dame, 2007) who assessed that in the active learning procedures, students use their brains, studying ideas, solving problems and apply what they learn. Similarly, the suggestion of Girma and Feyera (2019) indicated that student-centered pedagogy is vital to ensure excellence in instructional system. These are unquestionable methods of teaching that teachers use to develop the competencies and skills required for 21 st century classrooms.
(4) Gender has no role to play in mean achievement scores in natural science test learned by cooperative method intervening groups. Thus, there was no statistically significant difference in NSAT mean achievement scores between female and male students learned by cooperative learning methods as intervening groups. A similar finding was reached by Johnson and Johnson (1999) who stated that cooperative group learning leads to improve student performance and increases higher-order thinking skills of students without differentiation.
(5) The cooperative intervening school performed better than the control school due to peertutoring among the cooperating group than the control group that did not cooperate to solve problems during interventions. This finding aligns with the finding of Bonwell and Elson (1991) that summarized that CLM engages students in activities and creates a classroom environment that permits students ownership of learning process. This, in turn, results in improved students' performance and creating positive student attitudes towards the learning process.
(6) There were direct relationships between the utilization of CLM interventions and students' learning engagement and outcomes. This indicated that the interventions achieved its efficacy and effectiveness of trials under optimal condition. This finding was supported by the finding of Mohamed (2008) which suggested that in cooperative learning students work together on problems in a small group setting until all members of the group understand the problem and complete it.

Conclusions
Teachers' professional learning practices improve their professional and pedagogical competencies and skills, and ultimately utilization of cooperative learning in classrooms. This practice improves students' positive interdependence, individualistic accountability, social skills, communication skills and group processing skills, students' learning engagement and outcomes. The quality of how well the interventions were implemented was evaluated according to Daniel et al. (2015), and the findings of this study revealed that students taught using cooperative learning strategy performed better in NSAT than those taught using the lecture method. The CLM interventions promoted high order thinking, learning and academic achievements of primary school students in biology, chemistry, physics and mathematics as compared to LM because of their interdependence, taking individualistic accountability, social skills, communication skills and group processing skills improve implementation of cooperative learning method. The cooperative intervening group performed better than the control group due to peer tutoring to solve the problems they set in their learning. Besides, the intervening group did better than the control group because members of the groups pooled their resources together to solve a common problem. The members worked harder on the tasks to succeed and those who recognized better than others improved their knowledge and skills while coaching or tutoring others. Therefore, cooperative learning strategy enhanced conceptual understanding than the lecture method. Moreover, there were no statistically significant differences in academic achievement in science instruction due to gender difference. Hence, the directional alternative hypotheses number 1, 2 and 5, and the null hypothesis number 3 were accepted. Conversely, the null hypothesis, number 4 was rejected and rephrased. Therefore; (1) Ha 1 (not rejected): Students who were exposed to CLM interventions achieved higher means in NSAT than those who were not exposed to interventions.
(2) Ha 2 (not rejected): Students who were exposed to CLM interventions achieved higher means in NSAT in different cognitive and psycho-motor levels than those who were not exposed to interventions.
(3) H O3 (not rejected): There was no statistically significant difference in mean scores in NSAT gender-wise between students who were exposed to interventions.
(4) H O4 (rejected and rephrased): There was no statistically significant difference in posttests in mean achievement scores of students who were exposed to and not exposed to post interventions.
(5) H O5 (not rejected): Natural science teachers who were exposed to utilization of CLM develop better pedagogical skills than those who were utilizing LM.
(6) This small-scale study has the possibility to be scaled up due to its strong effect size (0.566).

Recommendations
The following suggestions were raised as a direction of plan for future action. These are: (1) Teachers' professional learning practices should be focused on exercising specific method of teaching or learning to improve their subject matter professional competencies and pedagogical skills to improve students' learning engagement and academic achievement.
(2) CLM interventions should be encouraged in primary schools for enhancing academic achievement of students while the use of LM in teaching and learning should be reduced in natural science.
(3) The lack of taking responsibility and commitment were observed at different educational hierarchies to solve critical problems linked to the implementation of CLM which illuminates wider gaps between theory and practices. Hence, natural science curriculum designers should incorporate innovative pedagogical skills into teachers' education programs to enhance the applications of practical knowledge in classroom practices.
(4) Educational scholars should look for encouraging students' participation by using best models of CLM to address the principles of effective teaching and learning processes in science. Hence, this study is an input that leads to critical pedagogical praxis in other subjects too.
(5) Science teachers should be motivated to use CLM to improve their students' achievement in their disciplines. Besides, teacher education training programs should introduce the practices of CLM in the form of workshops, conferences, and seminars. This ensures that science teachers are well grounded on effective teaching-learning approaches to promote high order thinking, critical learning and academic achievement of students.
(6) Responsible bodies had better plan financial resources or funds to scale up the implementation of CLM to other subjects such as languages, social sciences, moral and aesthetics.
(7) The practices of CLM should be institutionalized through renewing, reforming and restructuring thinking of education leaders (supervisors, principals, department heads), teachers and students in the school system.
(8) The students' learning engagement and outcomes should be strengthened by improving practices of learning communities in teachers' continuous professional learning to update their professional and pedagogical competencies, and students' positive interdependence, individualistic accountability, social skills, communication skills and group processing skills.

Limitations of the study
In spite of the current study's promising aids to the overall sympathetic understanding of the effects cooperative learning method on student learning, it is significant to acknowledge that the scope of our study was narrow because it requires vast human, material, money and time resources to ensure the causal-effect relationships through interventions in a wider context. Therefore, a more comprehensive study needs to be conducted by involving potential practitioners.

Highlights of the Results
• Teachers' professional learning practices improve utilization of cooperative learning method in classrooms. This in turn improves students' academic interdependence, individualistic accountability, social skills, communication skills and group processing skills, students' learning engagements and outcomes.
• The implementation of pragmatic cooperative learning method produced positive effects and enhanced academic achievements of students at knowledge, comprehension and application levels compared to lecture method.
• The cooperative experimental school performed better than the control school because of peertutoring and interdependence skills among cooperating group than the control group to solve problems during learning.
• There were direct relationships between the utilization of cooperative learning method and students' learning engagement and outcomes. This indicated that the interventions achieved its efficacy and effectiveness of trials under optimal condition.