Dramatic Interpretation uses tragic, heart-rending material. Watching a good DI is a very cathartic experience, to say the least. Most speakers in DI say they feel spiritually exhausted after any performance; they put their whole selves into it. You get your material from a play, usually with only two or three characters. More characters than that distracts the audience from the dramatic action. Note that you play all the characters; this distinguished DI from straight drama, and makes it speech event.
Humorous Interpretation is the opposite of Dramatic - you're looking for funny, feel-good material with lots of physical, situational humor. Though there are exceptions, the accurate stereotype of an HI performer is a speaker jumping around with hyperactive intensity, making unrealistic faces, and using the most outrageous accents possible. Material comes from a play, except that you want at least four or five characters. You play all of your characters, and you have to differentiate their voices/attitudes/stances a lot so the audience won't mix them up.
Oral Interpretation of Literature
Oral Interpretation of Literature is also called in some tournaments Poetry/Prose. They are ten minute pre-memorized speeches, just like original events, but the resemblance ends there. Students present selections in two categories -- prose and poetry. Each selection must be a maximum of ten minutes in length. The student must hold a manuscript and appear to be reading. The students alternate between rounds of prose and rounds of poetry. The poetry program may be a cutting of one poem or a collection of several poems. The prose program must be a cutting of only one work.
Storytelling is much like G-rated HI. Your audience is pictured as kiddies. So keep it clean, funny, and set for children. You're still looking for funny, feel-good material. Though there are exceptions, the oft-accurate stereotype of a Storyteller is a speaker jumping around, making unrealistic faces, and using the most outrageous accents possible.
Material comes from a published work of "children's literature." You want at least four characters. You play all of your characters, and must differentiate voices/attitudes/stances so the kiddies can follow along.
Duo Interpretation is basically a DI or HI with two people performing. Contestants may not touch each other or look each other in the eyes. The two must show interaction by doing their individual parts so it appears as though the two are actually talking to each other. All other rules and strategies applying to either DI or HI apply here. Students, should they opt for Duo, will also have a second forensic event at that same tournament. NFL rules allow for multiple characters for each performer. CFL and NoVaFL rules are quite strict.