This study examines the syntax of DP deletion and pragmatics of DP movement in passive voice from applied linguistics methodology. The data collection was a purposive sampling method as the study specifically alternated the data from Q1 SCOPUS publications, Thai national publications (TCI 1), and Thai undergraduate students’ independent studies (IS) from a private university. There were 99 tokens. The data analyses were linguistics and inferential statistics. Linguistic analysis follows generative grammar, whereas the statistical analysis follows inferential statistical analysis SPSS29. The results of the study showed the similarities of DP by-phrase agent deletion between Q1 SCOPUS, TCI 1, and IS. However, the results in these publications were different pragmatically. The discussion was explained syntactically and pragmatically. The DP arguments in passive voice were omitted due to the reason of widely-known agents. Pragmatically, the movement of DP argument in Q1 SCOPUS and TCI 1 complies with the theory of pragmatic discourse of givenness, while this was not applied in IS. It is expected that the results in this study would be useful for English learners in how to apply passive voice to write research methodology appropriately.