Samson Rosana OndigiMiheso_O‟Connor, K. MarguritePuotier, Zutaah2024-02-012024-02-012023-11https://ir-library.ku.ac.ke/handle/123456789/27396A Research Thesis Submitted in Fulfilment of the Degree of Doctor of Philosophy in Mathematics Education in the Department of Educational Communication and Technology, School of Education, Kenyatta University, November 2023.GeoGebra is a free computer application that provides geometry, algebra, and calculus views that have been adapted to the delivery of geometry concepts. Many students perceive geometry as difficult to understand. The study investigated the uptake of GeoGebra among preservice mathematics teachers in basic education colleges in Ghana and its relationship with performance in geometry. The objectives of this investigation were to: establish preservice Mathematics teachers‟ competencies in GeoGebra used in the instruction of geometry, investigate the attitudes of preservice teachers towards the integration of GeoGebra in the instruction of geometry, establish the difference in performance in geometry between preservice teachers in the treatment and non-treatment groups, establish if the use of GeoGebra results in gender differences in performance in geometry among preservice teachers, develop a prototype GeoGebra manual for use by mathematics teachers in Ghana. This research adapted the constructivist theory of social interaction that was propounded by Vygotsky in 1978. This research adopted the convergent parallel mixed-method design with the quasi-experimental method. The target population was 3062 first-year basic preservice mathematics teachers in the seven colleges in the Eastern Region of Ghana. Two (2) of the seven (7) colleges in the region, Colleges A and B, were randomly selected for the study. One intact class from each of colleges A and B was randomly selected with a sample of 174 participants drawn from the two Colleges. The class with 74 participants in College A was assigned as the treatment group and the class with 100 participants in College B was the non-treatment group. Participants in the treatment group learned geometry using GeoGebra for eight weeks while their colleagues in the non-treatment group learned the same content utilizing traditional methods. The study instruments were questionnaires, in-depth interview schedules, geometry achievement tests, and an observation checklist. A pilot study was conducted in a college that was not part of the study. The questionnaire recorded a Cronbach's Alpha value of 0.80. The study observed the reliability coefficients of 0.76 and 0.81 for the pretest and posttest respectively using the Spearman-Brown formula. The instruments were validated using content, construct, and face validity. Data were reported using descriptive statistics and analyzed utilizing independent samples t-test, and paired samples t-test. The finding indicated an increase in competency level of 75%. GeoGebra has a significant positive effect on student‟s engagement with geometry concepts and improves learners‟ interest and academic performance in geometry. The study found a statistically significant difference in performance in geometry between the experimental group and the control group (p = .000 < .05 at the 2-tailed level of significance). There was no significant difference in geometry performance between male and female participants. GeoGebra can improve performance in geometry among preservice teachers. This study recommends that GeoGebra be used in instructing geometry as a way to improve performance among prospective mathematics teachers. A prototype training guide specific to teacher education has been developed based on the outcomes of this research.enGeogebraGeometryBasic Preservice TeachersCollegesEastern RegionGhanaThesis