Browsing by Author "Girma Gezahegn"

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    Effects of Blended Learning on Addis Ababa University Students‟ Reading Comprehension: College of Business and Economics in Focus
    (Addis Ababa University, 2025-06-24) Dagnachew Tsegaye; Girma Gezahegn
    The general objective of this study was to investigate the effects of blended learning (BL) on Addis Ababa University students’ reading comprehension. Students’ attitudes toward blended learning-based reading comprehension were also examined. To fulfill this purpose, a quasi-experimental research design with mixed method approach was employed. In addition, from the College of Business and Economics at Addis Ababa University social science stream, four sections of freshman students were purposely selected and assigned to experimental (n=42) and control (n=42) groups. This was followed by a 12-week experiment involving students at Addis Ababa University in the first semester of the 2024/25 academic year. The same reading comprehension contents adapted from communicative English skills I course were taught to both groups. The only difference was that the experimental group was taught by a BL method that combined both online and face-to-face instructions, while the control group used the conventional, teacher-centered instruction. SPSS version 26 for quantitative data and NVivo 10 for qualitative data were used to analyze the data gathered from pre-posttests, attitude questionnaire, and focus group discussions (FGDs). Based on the analysis of the reading comprehension test results, the experimental group showed a large effect size and a statistically significant difference in reading comprehension components at the p < .05 level. However, the control group's reading comprehension results revealed no statistically significant differences in the pre- and posttest results. According to the results of the independent samples t-test, the experimental group scored better in all reading comprehension components than the control groups. Besides, students’ attitudes toward blended learning-based reading comprehension were examined through descriptive statistics for closed-ended questionnaires and thematic analysis for open-ended questions and FGD, using Nvivo 10 software. The major findings indicated that the blended learning (BL) approach positively affected students’ reading comprehension skills, with most students in the experimental group expressing positive attitudes toward it. The results leading to the recommendation that BL should be integrated into EFL classrooms to promote reading skills. Consequently, it would be advantageous to incorporate blended learning approaches that integrate online reading resources with conventional face to face instruction to improve students’ reading comprehension skills at the tertiary level in Ethiopia.
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    Relationship Between Wild Rice Species of Ethiopia With Cultivated Rice Based on Issr Marker
    (Addis Ababa University, 2007-07) Girma Gezahegn; Bekele Endashaw (Professor)
    Three wild rice populations of Ethiopia (one from Gambella and two from Gonder) and three cultivated rice populations (O. sativa from Gonder, O. glaberrima from West Africa and NERICA rice (NERICA-3; cultivar developed through interspecific hybridization between O. sativa and O. glaberrima), from Gonder) were studied. Inter simple sequence repeats (ISSRs) as a molecular marker was used to assess genetic diversity both within and between species using six ISSR primers, where four of them were dinucleotides and two tetranucleotides primers. A total of 93 clear and reproducible bands were amplified from the six ISSR primers. Both UPGMA and neighbor joining trees were constructed for each individual and population using Jaccard’s similarity coefficient of ‘0’ absent and ‘1’ present data. The trees clearly indicated six distinct groups which are based on populations of origin. The PCO analysis also recovered the UPGMA and neighbor joining trees groups, although wild Gonder-1 intermixed with wild Gonder-2. O .glaberrima, O. sativa and NERICA-3 clustered as a major group while O. barthii and O. longistaminata were clustered as the second major group. Such clustering of O. glaberrima with O. sativa and NERICA-3 is considered to be due to genetic admixture of O. glaberrima with O. sativa. The genetic diversity result generally indicated that wild rice populations were found to have higher gene diversity (0.14) than cultivated rice populations. The over all gene diversity and percent polymorphisms were found to be higher in wild rice than in cultivars (0.11). The Shannon’s diversity index also confirmed the existence of higher diversity in wild rice populations of Ethiopia than cultivated species used in the present study. Furthermore, partitioning of the Shannon’s diversity showed that the majority of the variations were observed among population (63%). Similarly, AMOVA demonstrate highly significant (P=0.00) genetic differences among populations within groups, among groups (cultivated and wild) and within populations. Of the total variation, 49.4% was attributable to among populations within groups, 26.4% to among groups and the least, 24.2% to within populations. Key words: genetic diversity, wild rice populations, cultivated rice, Oryza sativa, Oryza glaberrima, NERICA, ISSR