THE CORRELATION BETWEEN LEXICAL DENSITY AND VALIDITY OF READING COMPREHENSION TEST

This study is intended to find out if lexical density significantly contributes to reading
comprehension difficulty. For this purpose, the study was designed by descriptive
quantitative correlational design. Coefficient correlation between its high and low lexical
density was taken as the indicator of the contribution of lexical density to reading
comprehension difficulty. Reading Comprehension part of the TOEFL test was taken as one
of the variables, which is also called a criterion. This test is assumed to be standard in
difficulty level because this test has high validity. Two researcher-made tests of Reading
Comprehension – one of which is with high lexical density and the other with low lexical
density- were taken as the other variables. The level of text density is found by measuring
the lexical density percentage of Ure’s formula and categorize their level based on
Kamahami’s lexical density parameter. This study involved thirty students from class XI
IPA 1 SMA Dr. Wahidin Sudirohusodo as a sample taken from 263 students as a population
of all students in class XI. The data obtained from the three different sets of instruments
were analyzed by both simple and multiple correlations using the Pearson product-moment
formula.
The results of the study showed that there is a significant correlation between reading
comprehension test with low lexical density and reading comprehension test with high
lexical density towards TOEFL reading comprehension test (R = 0.816) with F-change
(26.9) > F-table (3.35) at the significance level of 5%. However, the correlation between the
reading comprehension of low lexical density and the reading comprehension section of the
TOEFL (r = 0.772) is not significantly different from the correlation between the reading
comprehension of high lexical density and the reading comprehension section of the TOEFL
(r = 0.770).