Research methods and statistical analysis is typically the least liked and most anxiety provoking aspect of a psychology undergraduate degree, in large part due to the mathematical component of the content. In this first cycle of a piece of action research, students' mathematical ability is examined in relation to their performance across different assessments. A maths test, including only components relevant to psychological research and analysis, was designed and subsequently completed by 427 students. Factor analysis revealed three distinct facets: understanding of mathematical procedures; interpretation of findings; and understanding the semantics of mathematics. Only the procedural and interpretative factors were predictive of overall course performance. Higher scores on both factors predicted better performance on multiple choice questions assessment and an unseen exam, whereas only the interpretation factor predicted performance on a critical thinking assignment and a lab report. The findings are considered with a view to developing another cycle of action research that more actively involves students.