This study examined the effectiveness of guided data-driven learning (DDL) activities on helping technological university students with a lower-intermediate proficiency level to learn grammar and vocabulary topics for the TOEIC test. The question of whether inductive learners make more progress than deductive learners was also addressed. A total of fifty-one non-English majors in a freshman English class participated in the study. Five computer-based and four paper-based DDL lessons were developed to increase students' awareness of the usage of particular grammar items and the distinction between three sets of synonyms. In order to determine the effects of the treatments, all the participants took pre-tests and immediate posttests. The results showed that there was a statistically significant difference between pre- and post-tests on grammar and vocabulary. However, inductive learners did not outperform deductive learners. As for students' perception of the treatments, it is noteworthy that they tended to take a neutral to less than positive attitude towards this DDL experience even though such an experience helped them significantly improve. The results suggested the existence of a gap between students' perceived satisfaction and their actual achievement. Pedagogical implications of these findings were discussed to improve the efficacy of DDL in Taiwan's EFL context.