This study investigated, using quasi-experimental research design, the effect of Igbo Language as medium of instruction on the enhancement of retention level of Primary 3 Pupils in Primary School Mathematics in Delta State Capital Territory (DSCT), Nigeria. The sample consisted of 2,400 Primary 3 pupils from six Primary Schools, in DSCT. Three Primary Schools were randomly assigned to the experimental and control groups, respectively. Three research questions and four null hypotheses guided this study. A validated and reliable instrument, Mathematics Assessment Test Item (MATI), was used to collect data. Difference in Mean Retention Level Scores was subjected to z-test analysis and was significant in favour of the experimental group. Vital recommendations were given to improve the use of Language of the immediate environment of the child as medium of instruction in schools in Nigeria.
Keywords: Igbo Language; Medium of Instruction; Enhancement of Retention Level; Mathematics; Primary School.
