Abstract :
Teaching vocabulary through derivational affixes is not an easy matter. The
reason is because derivational affixes are the process of forming new words
according to a fairly regular pattern on the basis of preexisting word. Moreover,
Boey (1975: 39) adds that derivational affixes are bound morphemes which
generally combined with the base to change its part of speech. Thus, it is
reasonable that SMA students face some difficulties to master this component of
the target language. That is why derivational affixes are expected to make students
interested in enriching their vocabulary.
The objective of the research is to find out whether there is significant difference
of vocabulary achievement between students who are taught through
derivational affixes explication and students who are taught through translation.
The research was done in SMA YP UNILA Bandar Lampung. The research was
quantitative research and used control group pretest posttest design. The
population of the research was the first year students of SMA YP UNILA Bandar
Lampung. The sample was chosen randomly by using lottery drawing. Three
classes were selected as the samples. Class X.10 was the try-out class, class X.9
was the experimental class, and class X.3 was the control class. The data gained
by administering a set of pretest and posttest. Three treatments were conducted
between them. To find out the significant difference of the data, the researcher
computed it by using T-test.
The test showed that at the significant level of 0.05, it was attained that T-ratio
was higher than T-table, that is 3.20 > 2.00. It means that derivational affixes
explication was effective in increasing students’ vocabulary achievement.