Columns come in many forms and are defined by their author's ownership of a guaranteed space to write. Effective columns require clarity of thought, a clear message, and an engaging style. The writer must plan their main ideas and opinions ahead of time to avoid being bland or fence-sitting. Columns aim to provoke a reaction from readers through agreement, disagreement, amusement or enlightenment. Successful column writers possess personal qualities like humor as well as professional qualities like being highly educated, widely read, verbally skilled, and knowledgeable about journalism ethics. There are many types of columns including reporting columns, opinion columns, gossip columns, and advice columns.