This study revisits categorization of infant engagement used in infant language acquisition research. We provide a novel, component-based analysis of interaction structures – centered on attention, interaction, and goal-oriented behavior. With this approach, we are able to extend the classification of engagement by differentiating two independent categories of engagement that have been overlooked. To verify this new categorization, an experiment was conducted with 84 participants in regard to the presence/absence of goals in naturally observed infant interactions form a Western and a non-industrial community. Results demonstrate that the extended categorization of engagement levels via interaction components and processes is sound because there are no significant differences between sites, and no significant differences between participants and trained coders. These results further support the use of a more extensive categorization of engagement, as well as the use of natural observation data and cultural immersion in language acquisition studies.