Impact of Density and Distribution of Unfamiliar Lexical Items on Iranian EFL Learners’ Successful Reading Comprehension Achievement

Density and distribution of Unfamiliar Lexical Items (ULIs) appear to influence learners’ Reading Comprehension Achievement (RCA). This study concerns the impact of these two variables on Iranian EFL learners’ RCA. For this, two groups of students timetabled for the experiments designed to assess learners’ RCA. To determine the participants’ levels of proficiency a Quick Proficiency Test was first given to the total population of 87 students and 60 selected as participants. They were then divided into four subgroups of 15, each of which took the pertaining text as the treatment. To do so, three short passages were administered, two for the density and one for distribution. Then, data were gathered from the questionnaires and answers analyzed by SPSS. The results revealed the participants in low density/distribution subgroups outperforming their counterparts in high density/distribution subgroups on tests devised to measure the learners’ inferencing of ULIs boldfaced in the texts. The selected method was a quasi-experimental, post-test only design and the procedures comprised short passages, multiple-choice tests, and statistics. To conclude, ULIs found detrimental to the learners’ successful RCA in the foregoing experimentation, where it can serve as a resource to the EFL development programs.