According to previous studies, visual data help to enhance vocabulary learning in a foreign language (e.g. Yeh and Wang 2003). However, it is not easy to create visual data for all lexical items. Particularly, we encounter problems when dealing with abstract words.In this paper, we report on two experiments that tested the learning effects of four types of materials for mobile devices that were based on the following contents: 1. translation only, 2. aural data only, 3. visual data only, 4. aural and visual data. In Experiment 1, the 59 subjects were instructed to memorize the lexical items that were stored in 4 different types mentioned above, and vocabulary tests were administered in order to measure the memory retention rate of the meaning of each word.Contrary to previous findings, the material employing aural data only drew out the best results. In addition, the material employing just translation scored better or did as well as either the translation + visual data or the translation + visual + aural data. This implies that contrary to claims found in the literature, visual data may not be so significant a factor in vocabulary learning. However, the difference was not statistically significant. In order to test the validity of this result, we conducted Experiment 2, following similar procedures. 40 subjects participated in the experiment. This time, again, visual data did not seem to provide much aid in facilitating vocabulary attainment, since the mean test scores were similar between translation only and translation + visual material.The results from these two experiments suggest that contrary to claims in the literature, we may not need to rely too much on visual data in vocabulary attainment. Furthermore, material based on text data only may also prove to be an effective means of learning vocabulary in a foreign language.