Incidental vocabulary learning from listening, reading, and viewing captioned videos: frequency and prior vocabulary knowledge

The present study, given increasing attention to incidental vocabulary learning, explores how different input modes (i.e., listening, reading, and viewing captioned videos) affect such learning while considering frequency and prior vocabulary knowledge. One hundred twenty Chinese university students learning English as a foreign language were allocated to three treatment groups and one (test-only) control group. Target words included 48 terms appearing at various frequencies (1-6 occurrences) in a documentary video. Incidental vocabulary learning outcomes were measured through form and meaning recognition. Mixed effects models showed that the caption viewing condition led to the most pronounced incidental vocabulary learning and retention outcomes, followed by the reading and listening conditions. A significant interaction effect was identified between time, group, and prior vocabulary knowledge. A significant interaction effect was also observed between time, group, and frequency. Meanwhile, frequency was less important for incidental vocabulary learning than prior vocabulary knowledge. Pedagogical implications are discussed based on these findings.