Referring Effectively to a Group of Objects

In communication, we often need to refer to multiple objects. We have several possibilities: enumerating the objects one by one or referring to a shared feature. This is the first study to systematically compare different ways of referring to groups of objects in terms of response times, accuracy, and memory encoding. In a within-subjects design, participants listened to instructions either using a shared feature or enumerating coordinates of individual objects We find that there is no one way of referring that is universally more effective, but that the optimal way of referring depends on the type of common feature and the number of objects. When the shared feature is prominent, such as color, and multiple objects need to be identified, referring to it results in shorter identification times and fewer errors. In contrast, when the shared feature is less salient, such as pattern, referring by location tends to be better.