2.2. Incidental vocabulary learning
Vocabulary, the core of the language, is not acquired at one shot. It necessitates a long
process. Throughout this process, learners become familiarized with the encountered words.
What makes them familiar with words for acquisition is the frequency of their usage and the
number of encounters in different forms and contexts (Nation, 1990; Schmidt, 2001). Yüksel
and Tanrıverdi (2009) claimed that vocabulary acquisition occurs along a continuum of
development, as presented in Figure 1. Furthermore, they suggest that a pre-test and a posttest
must be separated by a longer period and conducted in contrast with other learning setups
(e.g. other media or means to learn words).