Native speakers’ introspective judgments of sentence acceptability have been an essential tool for linguistic research. However, this traditional method of data collection has been criticized in various respects, and the crucial criticism concerns its methodological ‘informality’. Since the work of Bard et al. (1996) and Cowart (1997), more formal experimental methods have been gaining popularity in a trend known as ‘experimental syntax’. The present study reports two experiments of acceptability judgments. We explore the utility of experimental syntax in the area of Korean syntax via a direct comparison of the results of informal judgment collection methods with the results of formal judgment collection methods. Our study presents the large-scale comparison based on a random sample of phenomena from a linguistic journal in Korea. We tested 121 data points from the approximately 6,052 Korean data points that were published in the journal Studies in Generative Grammar between 2003 and 2013. We tested this sample with more than 198 naïve participants using two formal judgment tasks (Yes-No and two-alternative forced-choice). The results show a convergence rate of 73% between informal and formal methods (YN 69%, FC 77%). Overall results indicate that formal judgments are shown to diverge from informal judgments given in the journal, which contrasts sharply from the 95% convergence rates reported in Sprouse et al. (2013).