In addition to certifications, specialized training is also required or appropriated to public safety dispatchers. As public safety dispatchers are the first contact made between the public and emergency services, public safety dispatchers need to be able to extract a vast array of information out of the caller. Such specialized training for 911 dispatchers can include: suicide intervention, hostage negotiation, bomb threats, tactical dispatching (for SWAT teams), domestic violence and domestic and foreign terrorism countermeasures. Many are also trained as Emergency Medical Dispatchers, able to give first aid instructions to victims or families prior to EMS arrival.