News anchors (formerly "anchormen") serve as masters-of-ceremonies and are usually shown facing a professional video camera in a television studio while reading unseen teleprompters. The anchors are often in pairs (co-anchors), who sit side by side and often alternate their reading. Meteorologists stand in front of chroma key backgrounds to describe weather forecasting and show maps, charts and pictures. Reporters research and write the stories and sometimes use video editing to prepare the story for air into a "package". Reporters are usually engaged in electronic field production (EFP) and are accompanied by a videographer at the scenes of the news; the latter holds the camera. The videographer or assistants manage the audio and lighting; they are in charge of setting up live television shots and might edit using a non-linear editing system (NLE). Segment producers choose, research and write stories, as well as deciding the timing and arrangement of the newscast. Associate producer, if any, specialize in other elements of the show such as graphics.