Biological anthropologists are interested in both human variation and in the possibility of human universals (behaviors, ideas or concepts shared by virtually all human cultures). They use many different methods of study, but modern population genetics, participant observation and other techniques often take anthropologists "into the field," which means traveling to a community in its own setting, to do something called "fieldwork." On the biological or physical side, human measurements, genetic samples, nutritional data may be gathered and published as articles or monographs.