The purpose of the present study was twofold: (a) it examined the relationship between peer-rated likeability and peer-rated oral presentation skills of 96 student presenters enrolled in a science communication course, and (b) it investigated the relationship between student raters' severity in rating presenters' likeability and their severity in evaluating presenters' skills. Students delivered an academic presentation and then changed roles to rate their peers' performance and likeability, using an 18-item oral presentation scale and a 10-item likeability questionnaire, respectively. Many-facet Rasch measurement was used to validate the data, and structural equation modeling (SEM) was used to examine the research questions. At an aggregate level, likeability explained 19.5% of the variance of the oral presentation ratings and 8.4% of rater severity. At an item-level, multiple cause-effect relationships were detected, with the likeability items explaining 6-30% of the variance in the oral presentation items. Implications of the study are discussed.