The study was conducted in Tanzania located on the East Coast of Africa. The country is inhabited by over 55 million people (United Republic of Tanzania [URT],2019).
Administratively, Tanzania is divided into 31 regions. This study was conducted in the Dodoma region, purposively selected. It has more than 200 secondary schools and it is marked by students’ poor performance in STEM. It was ranked in the least 11 performing regions for over 6 years (2014–2019). Out of 31 regions, it was recently ranked at 24th (MoEST,2016), 19th (MoEST,2017), and 21st place (MoEST,2018, 2019) in form four national examinations. Data were collected from 9 secondary schools based on performance in form four national examinations. Precisely, schools with high, average, and low-performing ranks were selected for this study (MoEST, 2019). Further, school locations, specifically from urban and rural Dodoma regions were taken into consideration for school selection.
4.2 Research Approach and Research Design
This study employed a mixed-method research approach. The qualitative approach was used to explore teachers’ and students’ feelings about classroom practices that favour language support in teaching and learning. This was done through inter- views with STEM teachers and focus group discussions with students. Further, the ex-post facto design, a quantitative approach (Kothari,2008) involving pre- and post- classroom assessments was employed. Formative assessment was applied to eval- uate the effectiveness of introduced pedagogical language strategies in teaching and learning of STEM, focussing on biology. Specifically, this study involved students from year four of the ordinary level of secondary education. The grade was selected because it is the one concerned with the topic of invertebrate systematic, Kingdom Animalia (URT,2020).
4.3 Data Collection
Data were collected between March 2019 and August 2020. The baseline study was conducted between March 2019 and February 2020, while the intervention was done from March to August 2020. A total of 54 sessions, each of 80 minutes were observed in 9 schools. A total of 36 teachers (STEM: 27—three from each school, Language:
9—one from each school) and 250 students (28 from eight schools and 26 from the ninth school) from level four of the ordinary level participated in the study. The sample size of students was chosen based on the recommended class size in Tanzania which should not exceed 40 students (MoEST,2019), while that of teachers depended on the number of biology and language teachers available at the school level.
The study was divided into three stages: lesson preparation, lesson implementation and lesson observation. Before each stage, a consent form was signed by teachers and students. When a student was less than 16 years old, ethical clearance was issued from parents. Further, participants were assured about confidentiality and guaranteed that data have to be only used for research purposes.
Stage 1: Pre-test and Lesson Preparation
This stage consisted of the lesson observation and formative assessment in biology focussing on systematic invertebrates. Data were collected using the interviews, observation checklist, marking the evaluation sheets and marks recording. Marks and lesson observations were used to formulate the intervention to help teachers and students to overcome identified challenges. The intervention consisted of training participant teachers and sharing the experience about the inquiry and strategies that can be used to support students with English language difficulties. Further, 20 teachers purposively selected, were interviewed before the training to get their views about supporting students with English language in the context of learning inverte- brate systematic. After the training, the 80 minutes biology lesson was prepared by improving the one observed, where the subject content and learning resources were revised and improved.
Further, the elements of language objectives were introduced as a new entity indicating lesson activities that would support students to improve the language of instruction and understand the lesson content. The language strategies focussed on the use of language supportive activities, translate when necessary, interpret for students, help students to pronounce correctly, use of language genres specific to the subject and topics, provision of a glossary, use of simple English sentences and bilingual instructions where Kiswahili and English could be used strategically to concurrently learn. Further, the research team recorded data on changes in the revised biology lesson plans and information obtained from experience sharing using notebooks.
Stage 2: Lesson Implementation and Lesson Observation
This consisted of teaching the lesson prepared in stage one. One of the teachers who participated in the lesson planning volunteered to teach, while others remained the observers. During the teaching and learning processes, students were given equal opportunities to learn and interact using both Kiswahili and English. During the group discussion, students were allowed to use Kiswahili and report in English.
Observers used a predesigned checklist to assess the effectiveness of pedagogical language strategies indicated in the lesson plan. Teachers’ interactions with students throughout the lesson were noted, the ability of students in speaking and reading skills were recorded, and challenges faced by teachers were also noted.
Stage 3: Post-lesson Evaluation
This stage consisted of the evaluation of the success of the lesson. Teachers and the research team reflected on successful points implemented as planned in the lesson; discussed the points that need improvement; and reflected on how the pedagogical language strategies supported the teaching process. To explore differ- ences experienced by students while teaching and learning using English only, and using both English and Kiswahili, the interview was organized with 90 randomly selected students and the focus group discussion was organized with 10 students at the school level. Data on the advantages of teaching using both Kiswahili and English were also collected through the interview with 20 teachers who taught the lesson.
At the end of the lesson, all students who attended the revised lesson were assessed using the content-based questions, prepared following Bloom’s taxonomy to verify the achievement of the objectives. Scripts were collected and marked focussing on the understanding of biology content and the English writing skills. The passing mark was fixed at 50%. To avoid biases in marking, scripts were checked by each member of the research team and then verified by a private person selected out of the research team, but having skills in assessment. Results were then recorded and compared with those of the pre-test to evaluate changes in performance. Finally, each student’s English writing, reading, speaking and listening skills were checked over the set of given writing and reading class session activity.
4.4 Control of Threats to Internal Validity
Based on Maxwell’s (2012) recommendations, we planned for intensive and long- term research study working with the same observers and participants over the systematic of invertebrate, subdivided into six class sessions and six subtopics. To ensure that data do not apply to only one observation or one sample population, multiple sources of data namely, students’ evaluation sheets, focus group discussions, and interviews with students and teachers were used. Further, Bloom’s taxonomy guided the development of the assessment questions for each session. Nevertheless, observed teachers were selected under conditions of being either a biology or English teacher, and having at least 6 years of teaching experience in secondary schools.
4.5 Data Analysis
Means and standard deviations were used to compare changes in student’s perfor- mance between pre- and post-tests. The paired samplet-test (Kothari, 2008) was used to check significant differences in performance before and after intervention
Table 1 Assessment of writing, reading and speaking skills adapted from Shohamy et al. (1992) and Knoch (2011)
Structure of paragraph Ranking category Ranking scale
a. Writing skills assessment
No errors in terminology, sentence structure and morphology
Correct 4
No errors in terminology and sentence structure, but with fairly correct morphology
Fairly correct 3 No errors in terminology and morphology but with errors
in sentence structure
Poor 2
No errors in morphology but has errors in sentence structure and terminology
Very poor 1
Errors in morphology, sentence structure and terminology Not correct 0 b. Reading and speaking assessment
Reading/speaking had the exact pronunciation, break in proceedings and fluency
Correct 4
Exact pronunciation without respect pauses and fluency Fairly correct 3 Reading adhered to pauses but did not follow the exact
pronunciation and fluency
Poor 2
Reading was totally not following the exact pronunciation, break in proceedings, and fluency
Very poor 1
Total failure to read the sentence Not correct 0
for the effectiveness of pedagogical language strategies and the understanding of the lesson content. Further, frequencies and percentages were used to test for the extent to which teachers used pedagogical language strategies and student’s English language skills evaluation. Thematic analysis was employed in the analysis of qual- itative information, and themes were developed based on the data generated. Data were analysed using SPSS Version 16.0 software. Further, the writing and reading skills consisting of categorical variables related to students’ performance were set to standards as per the five-point rating scale (Table1).