http://repository.mut.ac.ke:8080/xmlui/handle/123456789/4 2026-04-04T12:01:45Z http://repository.mut.ac.ke:8080/xmlui/handle/123456789/6911 Scaffold Extensions for Client Drift Mitigation in Federated Learning: A Synthesis of Approaches, Limitations, and Future Directions Muthii, James Mburu; Wanjau, Stephen K.; Njenga, Stephen Client drift arising from non-independent and identically distributed (non-IID) data across participating clients remains one of the most critical obstacles to effective Federated Learning. The Scaffold algorithm, which introduces control variates to correct local gradient updates, has emerged as one of the most prominent variance reduction methods for mitigating this drift. Although numerous extensions to Scaffold have been proposed, no systematic review has exclusively examined the Scaffold algorithm and the control variate mechanism for client drift mitigation, leaving the research community without a consolidated understanding of how Scaffold has been extended, what limitations persist, and which characteristics remain underexplored. This study addresses that gap through a systematic literature review guided by PRISMA 2020 guidelines. Seven electronic databases were searched for publications from 2016 to 2026, yielding 1,847 records, from which 33 studies were included after duplicate removal, screening, and full-text eligibility assessment based on criteria requiring each study to address Scaffold or control variates for client drift in FL and cover at least two performance metrics. Data were synthesized thematically using frequency counts and tabular summaries. The review reveals nine distinct extension approaches: variance reduction via gradient estimation techniques was the most prevalent (11 studies, 34%), followed by integration with advanced optimization algorithms (8 studies, 25%), together accounting for 59% of the reviewed work. Twelve Scaffold characteristics were targeted for extension, with variance reduction the most commonly modified (37%, rising to 50% with combined categories), while communication mechanism, privacy budget allocation, and similarity-based approaches remained significantly underexplored. Recurring limitations across all approaches included communication and computational overhead, hyperparameter sensitivity, restrictive theoretical assumptions, performance degradation under extreme data heterogeneity, and limited large-scale empirical validation. A notable finding is that similarity-based approaches for client drift mitigation are largely absent from the literature, with only one study employing a similarity measure. The review, therefore, recommends future investigation of similarity-based methods as adaptive control variates within the Scaffold protocol, alongside prioritization of communication-efficient, privacy-preserving designs validated at scale. This research was self-sponsored with no external funding. 2026-01-01T00:00:00Z http://repository.mut.ac.ke:8080/xmlui/handle/123456789/6907 An Analysis of Prepositional related errors in English Composition of Upper Primary Learners in Kieni East Sub County in Nyeri County Ngugi, Beth N.; Wairimu, Rosepaulah The research sought to investigate prepositional errors on English usage. There has been a big outcry in the field of English language learning about the falling levels of proficiency in English among students, particularly in upper primary level. This problem was attributed to inadequate mastery of linguistic skills and incomplete acquisition of English language. Therefore, the current paper investigated preposition errors as manifested in written compositions of upper primary learners. Prepositional rules in English language are inconsistent; that is certain prepositions can be applied in one form, but not in another. More so, prepositions are polysemous. Thus, learners often become frustrated when they have to determine prepositional meanings and when to use them appropriately. The research was guided by the following objectives; identifying prepositional related errors in learners' composition and describing the errors. The study applied Corder’s(1974, 1976) Error Analysis Theory. The study adopted a descriptive research design in order to vividly describe various errors encountered in the usage of English prepositions. The target population was 52 primary schools,168 teachers of English, and 408 pupils from Public Primary Schools in Kieni-East Sub County in Nyeri County. Data was collected using interview guides for the teachers and composition test for pupils. The study showed four main prepositional errors; errors of omission, addition, substitution and misordering. The study concludes that prepositional errors are more of lexical errors since they affect the meaning of the entire sentence. Thus, the study recommends that learners should be taught rules of prepositions systematically and that a revision of course books should provide specific rules that may lead to proper acquisition of prepositions. 2021-01-01T00:00:00Z http://repository.mut.ac.ke:8080/xmlui/handle/123456789/6906 Linguistic Strategies According to Gender as Reflected in the Kenya National Assembly Owuor, Boswell Omondi; Ngugi, Beth N. Gender is ever present in our conversation. It is used to explain everything and is embedded in our institutions, our actions, thoughts and beliefs. In this research, we set out to establish the linguistic strategies employed by the male and female members of the Kenya National Assembly to drive their agenda and to achieve successful communication. This research sets out to establish assembly members’ manner of speaking and general adherence to speaking norms on the assembly floor. Under such a background, the study examined language and gender in the Kenya National Assembly. The research questions were: what are the linguistic strategies employed by speakers on the assembly floor based on their gender? How do members react to the gendered linguistic strategies? The study employed the Politeness Theory. The data was collected from four randomly selected sessions in the 12th Parliament- also referred to as National Assembly. The analysis of data adopted a quantitative and qualitative approach. Audio-visual recordings from the National Assembly were transcribed for analysis. In this process, selective transcription was used for the purpose of the research. Analysis of the linguistic items was done. The study established that members of the National Assembly used the following linguistic strategies: being direct, being assertive, use of metaphors, were ironic among others. It was observed that most of the members reacted in the following ways: cooperation, showing understanding, among others. 2023-01-01T00:00:00Z http://repository.mut.ac.ke:8080/xmlui/handle/123456789/6905 Mother Tongue in the Classroom Setting – A tool for Enhanced Second Language Acquisition in Multilingual Societies Ngugi, Beth N. The study has addressed the critical role of using the mother tongue in the classroom for enhanced development of the English language. Despite the recognition of the critical role of first language (L1) in second language development, there is no clear guidance on how and when to use it. Teachers in Kenya lack clear guidance on how to develop learners’ mastery of the English language using leaners' mother tongue. Mastery of the English language has been a challenge to most of the learners who learn it as a second language. This may be attributed to a lack of proper guidance on the implementation of the language policy in Kenyan schools. The current study was undertaken to establish practised translanguaging during English language lessons and its implication on English language development. This was achieved by establishing how teachers used their mother tongue during the English language lesson and its implication. The study was guided by Communicative Language Theory (CLT) which emphasizes the transactional and functional roles of the language. This theory guided the evaluation of how teachers of English used learners’ mother tongue to teach English language concepts as well as interact with learners during the lessons. Three public primary schools in Kasarani Sub County in Nairobi County participated in the study. Audio-video recording supplemented by observation was the data collection method. Findings indicated that teachers used their mother tongue while explaining the meaning of words, paraphrasing sentences, and evaluating the understanding of a concept. Consequently, learners understood the concepts and improved their performance. However, teachers lacked clear guidance on how to use the mother tongue, which affects the positive impact of using the mother tongue. The study recommends that teachers be offered in-service courses on the effective use of translanguaging practice. The study adds knowledge of the existing theories on second language development. 2023-01-01T00:00:00Z