Guest Editors' Introduction: Labeling the World

Our actions in the physical world are increasingly linked with processes in the virtual world. The increased availability of machine-readable tags accelerates this merge and helps to blur the border between physical matter and digital bits in a variety of environments across the globe. This special issue on labeling the world presents five articles that together illustrate how labeling technology impacts human and machine processes today, samples application area diversity, and hints at where this powerful mechanism could take us tomorrow.