Conclusion
The result of this study corresponds to what was found in White’s study (1998)
when she found that input enhancement led to improvement in the experimental group,
though this improvement was not significantly different from that of the control group.
Although the results from this study are not suggestive about the distinguished impact
of input enhancement through printing types in that this type of enhancement did
not cause any significant differences among the different groups of learners, one fact abut L2 learning is confirmed. That is, positive evidence is important for L2 learning especially when the use of the linguistic features lack explainable reasons, like those prepositions following some verbs or adjectives, which are the features investigated
in this study
As Han et al (2008) note, the mixed results of research studies on the effects
of textual enhancement may result from the different designs, different ways of presenting
the target features, and different ways of assessing the learner’s improvement.
Moreover, these inconclusive results may be due to different target language features
studied in different studies. The effect of input enhancement and consciousness-raising
may be influenced by the nature of language features. In other words, input enhancement
may have an effect on the acquisition of some types of language features but not
others. Researchers may then need to keep investigating more carefully on this issue
as this may provide deeper insights into the understanding of the contexts where a
particular study on this issue is conducted and possible effects of input enhancement
and consciousness raising on the acquisition of different linguistic features with different
natures. Research synthesizing previous studies related to the impact of input
enhancement and consciousness raising may be needed. This research should try to
classify the types of grammar on which input enhancement and consciousness raising
seem to and do not seem to have an impact so that we can gain more understanding
about the interaction between the nature of linguistic features and the effect of this
kind of instruction.