1.1 Introduction
Class size refers to the number of students assigned to a teacher in a classroom at a particular time. Academic performance refers to the level of learning and achievement demonstrated by students through tests, examinations, assignments, class activities, and other forms of assessment. The relationship between class size and academic performance has attracted attention because the number of students in a classroom affects how teachers organise lessons, manage students, provide individual attention, and assess learning. According to the OECD (2024), class size is different from the student-teacher ratio because it measures the number of students grouped together in a classroom. The organisation also reports that the effect of class size on student performance is not the same in all educational settings.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the aim and objectives of the study. Others are significance of the study, scope of work, research hypothesis and questions, limitation of the study and definition of terms.
1.2 Background of Study
Class size has remained an important issue in education because the number of students placed in a classroom affects the way teaching and learning take place. According to OECD (2024), class size is measured by the number of students who are grouped together for a common course of study. A classroom with fewer students is generally easier for a teacher to organise, while a classroom with many students requires greater effort in classroom management and supervision. The issue is therefore not only about the physical size of a classroom but also about the amount of attention and teaching support available to individual students.
According to Filges et al. (2018), research on class size and academic achievement has been conducted across different countries and educational levels. Their systematic review examined studies involving students from kindergarten through secondary education and showed that findings differed across studies. This suggests that the relationship between class size and academic performance is not necessarily the same in every school or learning environment. Similarly, the effect of class size has to be considered alongside other factors that influence learning.
In the classroom, teachers are expected to explain lessons, ask questions, monitor students, correct mistakes, give assignments, assess understanding, and maintain discipline. When the number of students is high, carrying out these activities becomes more demanding. A teacher may have less time to attend to each student's learning difficulties. On the other hand, a smaller class is potentially capable of providing more opportunities for students to participate in lessons and receive individual attention. The OECD (2025) reported that smaller classes are generally viewed as creating better opportunities for individualised attention, although the overall evidence concerning their direct effect on academic performance remains mixed.
Nye, Hedges, and Konstantopoulos (2000) stated that the Tennessee Student/Teacher Achievement Ratio experiment provided evidence that students placed in smaller classes recorded academic benefits under the conditions of the experiment. The study was important because students and teachers were assigned to different class-size conditions, allowing researchers to examine the effect of class size more directly. Supporting this position, Shin and Raudenbush (2011) also examined the causal relationship between class size and academic achievement using data from the Tennessee experiment. Moreover, international education data show that class sizes differ considerably between countries and educational systems. OECD (2025) reported an average class size of 21 students at the primary level and 23 students at the lower secondary level across OECD countries. These figures are not standards that automatically apply to every country, but they show the differences that exist in how students are grouped for instruction. In developing educational systems, schools often have to deal with growing enrolment, limited classrooms, shortages of teachers, and inadequate instructional resources. Such conditions make class size a practical concern for school administrators and teachers.
This study is set against the backdrop of the need to understand whether class size is significantly related to students' academic performance and to provide evidence that is relevant to teachers, students, school administrators, parents, and education planners.
1.3 Statement of Problems
Investigation revealed that some classrooms have large numbers of students, making effective supervision and individual attention difficult. In a small class, a teacher is generally faced with fewer students to teach and supervise. In a large class, the teacher has to divide attention among more learners, while classroom control, marking, questioning, and participation become more demanding. However, class size alone does not determine academic performance. The OECD (2025) stated that evidence on the direct effect of class size on student performance remains mixed, although smaller classes are often associated with greater opportunities for individualized attention.
Furthermore, large classes reduce the amount of time available for teachers to attend to individual students. In addition, some students have fewer opportunities to ask questions, contribute to discussions, or receive personal feedback. It is against this backdrop that this study seeks to examine the relationship between the number of students in a class and their academic performance.
1.4 Aim and Objectives of Study
The aim of this study is to analyze the relationship between class size and academic performance of students.
The specific objectives of this research are to:
- Examine the relationship between class size and students' academic performance;
- Determine the effect of large class sizes on students' academic performance;
- Examine the influence of small class sizes on students' classroom participation and learning;
- Identify the major classroom challenges associated with large class sizes; and
- Determine measures for improving teaching and learning under different class-size conditions.
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:
- What is the relationship between class size and students' academic performance?
- How does large class size affect students' academic performance?
- How does small class size influence students' classroom participation and learning?
- What are the major classroom challenges associated with large class sizes?
- What measures are appropriate for improving teaching and learning under different class-size conditions?
1.6 Research Hypotheses
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
Hypothesis One
- H0: There is no significant relationship between class size and students' academic performance.
- H1: There is a significant relationship between class size and students' academic performance.
Hypothesis Two
- H0: Large class size has no significant effect on students' academic performance.
- H1: Large class size has a significant effect on students' academic performance.
Hypothesis Three
- H0: Small class size has no significant influence on students' classroom participation and learning.
- H1: Small class size has a significant influence on students' classroom participation and learning.
Hypothesis Four
- H0: Large class size has no significant relationship with classroom management challenges.
- H1: Large class size has a significant relationship with classroom management challenges.
Hypothesis Five
- H0: Measures for improving teaching and learning under different class sizes have no significant relationship with students' academic performance.
- H1: Measures for improving teaching and learning under different class sizes have a significant relationship with students' academic performance.
1.7 Significance of Study
The outcome of this research will provide information on how classroom size relates to learning conditions, participation, and academic performance. The study will also provide information that relates class size to teaching, classroom management, assessment, and student interaction.
Furthermore, the research outcome will provide information relevant to classroom organisation, teacher allocation, and student enrolment. It will also provide information about classroom conditions that relate to students' learning and academic performance.
Lastly, the study will provide evidence relevant to decisions concerning teachers, classrooms, student population, and educational resources.
1.8 Scope of Study
This study focuses on selected secondary schools in Rivers State, Nigeria. It examines the relationship between class size and academic performance of students. The study covers class size, students' academic performance, classroom participation, classroom management, and the challenges associated with large and small classes. The study is limited to selected students and teachers within the selected schools.
1.9 Limitations of the Study
During the course of this study, there were some problems encountered which stood as limitations to the research work. Some of the limitations include:
- Delay from Respondents: Some respondents delayed in completing and returning the research instruments, which affected the speed of data collection.
- Financial Constraints: Limited funds affected transportation, printing, photocopying, communication, and other expenses associated with the research.
- Time Constraints: The study was carried out within a limited academic period, which restricted the time available for data collection, analysis, and writing.
1.10 Definition of Terms
Academic Performance:
Academic performance refers to the level of achievement demonstrated by a student in schoolwork, tests, examinations, assignments, and other academic activities. In this study, it refers mainly to students' measurable educational outcomes.
Class Size:
Class size refers to the number of students grouped together for instruction in a classroom. OECD (2024) defines class size in relation to the number of students following a common course of study.
Academic Achievement:
Academic achievement refers to the knowledge and skills demonstrated by students through educational assessments. It is often reflected through test scores, examination results, grades, and other measures of learning.
Student:
A student is a person formally enrolled in an educational institution for the purpose of receiving instruction and acquiring knowledge and skills.
Teacher:
A teacher is a person responsible for providing instruction, guiding students, assessing learning, and managing classroom activities.
Classroom:
A classroom is a designated learning space where teachers and students meet for instructional activities.
Large Class Size:
Large class size refers to a classroom containing a relatively high number of students, resulting in more learners being handled by one teacher during instruction.
Small Class Size:
Small class size refers to a classroom containing a relatively low number of students, allowing the teacher to work with fewer learners during instruction.
Classroom Management:
Classroom management refers to the methods used by teachers to organise students, control behaviour, maintain order, and create conditions suitable for learning.
Student Participation:
Student participation refers to the involvement of students in classroom activities such as asking questions, answering questions, discussions, group activities, assignments, and other learning tasks.
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