Positivist epistemology can be the topic of a very boring lecture in an introductory social science or methods course. Fortunately, an activity borrowed from an elementary math class can alleviate the boredom by asking students to identify the sources of their own beliefs about unobservable phenomena and to explore questions about what constitutes an explanation.
The basic outline of this activity, which I use during the second class session of most courses I teach, is that unusual objects are concealed in opaque fabric bags. Small groups of students must attempt to describe and identify the object as thoroughly as possible without opening the bag. A recorder observes the group’s discussion and notes what data points they establish, how they negotiate rival hypotheses, and what threshold or pieces of evidence convinced group members about their findings. The process of investigation, discovery, and persuasion is repeated with several different bags, so that each group gets at least 3 objects. We then discuss what they learned about the objects, and as I reveal each item I link it to concepts in positivist epistemology such as what constitutes sufficient evidence, whether we ever can know for sure without being able to observe things, the role of context in defining the meaning of an observed act, and precision and accuracy in measurement.
This activity has been around for a while; I published it in PS: Political Science and Politics in 2006. Since then, it’s been picked up in history, linguistics, and psychology classes. The article goes through sources, ideas, and materials in more detail than I can here. The objects you use can vary, but I strongly recommend that you keep the two bags with film canisters or other containers (one with cotton balls inside, one without), and the bag with a piece of fabric ribbon. These objects allow you to get at issues of precision, accuracy, unobservability and authority most efficiently.
My own set of objects has evolved, and it shifts from course to course depending on the points I want to emphasize. My methods course, for example, emphasizes the difficulty of doing measurement across time and space. To raise this point, one of the bags includes the cake topper from my wedding – a simple engraved acrylic block intended as an executive award or paperweight. Most groups identify that it’s plastic and engraved and probably a paperweight… but without knowing what the engraving says, its context is completely unknown and the object’s significance is vastly misinterpreted. Out of its original context, our identification – coding – of that object was totally incorrect.
I’ve been using this activity for over a decade now and haven’t made any major improvements or changes to the version described in the PS paper. I strongly encourage you to give it a try: let your students’ own curiosity drive their understanding of how researching unobservables works.