From the web site:
ESEM, the International Symposium on Empirical Software Engineering and Measurement, is the premier empirical software engineering and measurement conference.
The objective of the International Symposium on Empirical Software Engineering and Measurement (ESEM) is to provide a forum where researchers, practitioners, and educators can report and discuss the most recent research results, innovations, trends, experiences, and concerns in the field of empirical software engineering and metrics.
This conference encourages the exchange of ideas that help explore, understand, and model phenomena in software engineering from an empirical viewpoint. The conference focuses on the processes, design and structure of empirical studies, and the results of specific studies. Studies may vary from controlled experiments to field studies and from quantitative to qualitative studies.