The goal of this study is to explore new tools for analyzing scientific sense-making in out-of-school settings. Although such measures are now common in science classroom research, dialogically based methodological approaches are relatively new to informal learning research. Such out-of-classroom settings have more recently become a breeding ground for new design approaches for tracking scientific talk and ideas within complex data-sets. The research reported here seeks to understand the language people "do" use to make sense of the life sciences over time. Another goal of this study is to track biological themes over time, using a new analytical scheme--the Tool for Observing Biological Talk Over Time. Our analyses are linked to and informed by tensions between particularistic and holistic data collection and analysis, qualitative and quantitative representations, and everyday and formal science discourse. These tensions and our analyses are linked to larger theoretical frameworks and to the recursive interplay between theory and practice. (Contains 2 tables, 3 figures and 3 notes.)