Tabling events and pop-up museums are common informal education experiences where institutions set up temporary displays in association with a specific theme. These events typically aim to engage large audiences in a short period of time. Within these informal education settings, participation is voluntary, which implies that visitors are at least curious about the content but are unlikely to participate in a lengthy formal evaluation. As such, we conducted an evaluation of a novel instrument designed to characterize audiences when interaction times are brief. The instrument is referred to as an Audience Matrix Tool (AMT) and operates as a platform for quickly recording visitor information. The AMT was implemented at four Florida Museum of Natural History pop-up events and two Raymond Alf Museum pop-up events to assess usability and adaptability. This exploratory study does not propose the AMT as a validated instrument, but rather introduces it as a potentially versatile tool for informal education settings.