Public Forum is a two-on-two debate event which involves research and case writing, and is a particularly popular style in China and the United States.
Asian Parliamentary (AP) and World Schools Debate (WSDC) are similar in nature. Both involve two teams of three people competing against each other. In Asian Parliamentary events, all topics are impromptu, meaning the students only hear the topic 30 minutes before the start of each debate. Students will debate a new topic in each debate round. World Schools Debate involves both impromptu topics and prepared topics. In Asian Parliamentary Debate, there are three seven-minute speeches given by each side and one four- minute speech. The basic speech structure of World Schools Debate is the same except that student deliver three eight-minute speeches and one four- minute speech. The amount of preparation time allowed in WSDC varies from competition to competition but typically ranges from 30 minutes to 1 hour. The interactive element of AP and WSDC is the allowance of Points of Information (POIs). POIs are when a speaker of the opposing side can stand and ask questions during the speech. This provides additional difficulty for speakers (as well as more entertainment for the audience).
British Parliamentary (BP) debate is unique because it involves four teams in each debate. Each team is competing for a ranking from one to four, as opposed to a simple win against the opponent. In BP debate there are two people on each team. All topics are impromptu topics and the students only have 15 minutes to prepare for the debates after hearing the topic. There are a total of eight speakers in the debate and each speaker delivers a seven- minute speech. Like other parliamentary debate styles (AP and World Schools) the interactive element of the debate is Points of Information (POIs).
You can type the specific format to find out more information about each format.