Browsing by Author "Abate, Tsedeke"

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    Development of Tools and Assessment of Ethiopian Students’ Pattern of Scientific Reasoning at the Upper Primary Level in the Hadiyya Zone
    (AAU, 2020-12) Abate, Tsedeke; Michael, Kassahun (Dr
    Studies indicate that the failure of science education to meet the needs of the 21st century is to some extent due to the inability to incorporate scientific reasoning and higher order assessments in the school instruction. Though the outcomes of education seek higher-order thinking abilities there is a lack of high ability assessments in low-income nations. The purpose of this mixed methods research is to explore students’ way of reasoning and develop and validate the Scientific Reasoning Progress Tool (SRPT) which measures students’ reasoning abilities. The phenomenographic study was used to explore grade eight students’ patterns of reasoning, and to validate an assessment tool the descriptive survey method was used. The qualitative analysis of students’ interviews elicited three major themes of student views towards different levels of scientific reasoning: naïve, mixed, and scientific along with the underlying ways of reasoning. For the quantitative part of the study, 40 items were developed, pilot tested, and administered for 242 grade eight students at six schools. Rasch Analysis was used to develop and validate the items with the help of Winsteps. It was found that the SRPT is offered as a valid and reliable instrument that is a construct-driven, domain-specific, and a higher-order thinking assessment that can measure students’ reasoning progress. However, it was found that the reasoning ability of grade 8 students’ is limited to lower level reasoning and they faced difficulty in attaining higher-level reasoning like iv generating evidence and drawing conclusions. This study has produced a valid and reliable assessment tool to measure students' scientific reasoning abilities and a theoretical model that could be used to develop assessment tools. The framework and design of this research may be adapted to develop additional instruments to investigate the learning progression of students’ scientific reasoning in middle and high school classes in Ethiopian and other low-income countries.
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    Superposed Laser Output Light
    (Addis Ababa University, 2012-02) Abate, Tsedeke; Kassahun, Fesseha (PhD)
    We study the squeezing and statistical properties of the superposed output light from two identical three-level lasers. Applying the Q function for the superposed output light, we calculate the mean photon number, the variance of photon number, and the quadrature variance. It is found that the degree of squeezing increases with the linear gain coe cient. Moreover, the degree of squeezing of the superposed light is found to be twice that of the light from one three-level laser