Categories of jokes that aren't put on the show:
1. Jokes written for the room. Every day, the packet holds a few morbid, mean, or otherwise offensive jokes that were written just for the writers to hear. They're either hysterical or hysterically shocking, and they're fondly quoted after the joke read, when we eat the catered lunch off plastic plates on our laps.
2. Jokes with references deemed too obscure. I've noticed that comedy writers tend also to be trivia buffs. We've got a Jeopardy champion on staff, and I know there are others on the New York late night talk show circuit. When I lived in Chicago, I wrote for the computer trivia game "You Don't Know Jack," and when I first moved to New York, I wrote questions for Who Wants To Be a Millionaire? Even with that background, I'm regularly clueless about a few references made in the joke read each day. Other times, the entire writing staff knows a certain reference, but no one can tell whether or not it's common knowledge for our viewers. Today, after the joke read, at a group joke writing session (known here as a "gang"), we tried to figure out if the Daily Show audience would understand if we called Mayor Giuliani's decency council idea "Karen Finley yam-ass bad." The head writer and executive producer thought no. They were probably right.
3. Jokes that are considered "hack." A hack joke's been done over and over and over. Hack is "I just flew in from Los Angeles and boy, are my arms tired." Sometimes "hack" doesn't refer to a specific joke so much as a style or subject of jokes. Unless you really have a clever or absurd take, a joke about airline food will be hack. A joke with the punch line "I hardly know her" will tend to be hack. "Bush is dumb" jokes are quickly becoming hack. Hack isn't necessarily unfunny, it's just well-traveled territory. We often play around with subverting hack jokes; you'll sometimes see them on the show. They also show up on The Simpsons. Here's my clearest example. The hack joke goes "Cathy sure is fat. When she sits around the house, she really sits around the house." The subverted joke goes "Cathy sure is fat. When she sits around the house, she really eats a lot and watches TV." You untwist the original comic twist. People sometimes call these jokes "anti-comedy." Anti-comedy can get a big laugh, but it's more popular among writers than it is among audience members.
4. Jokes that will get claps instead of laughs. This is tricky. We are strongly encouraged to make jokes that have a point. If, for instance, Mayor Giuliani creates a six-member decency council to determine what artwork is obscene, we should point out that every member he wants on the panel happens to be a white man over the age of 60. But it's hard to get that detail across in a joke that's funny rather than didactic. When a joke becomes didactic, the studio audience will clap instead of laugh. They want to show they support the stance we've taken, but they're not really amused. It's labor-intensive but satisfying to take a joke that seems like it'll get claps and alter it slightly till it gets laughs. On the other hand, it's heartbreaking to take a joke that's funny and change it so it has more of a point. Both occasionally happen at our show.
5. Jokes that could start a lawsuit. Everyday, a script of the show goes to our legal adviser to be OK'd before the taping. Decisions are made on a case-by-case basis, but we all know to avoid certain areas. For instance, the Church of Scientology is not the subject of jokes on The Daily Show. And The Daily Show does not put beloved children's characters into adult situations. You get the idea. Also, when working off a sound bite, no matter how mean the man-on-the-street sounds, we can't follow him up by saying something like, "This man then left to check on the body in his trunk."
6. Jokes that don't get a laugh in the joke read. They're dead. There are exceptions, but they're few. If you want to up your chances, not only do you have to write good jokes in the morning, you have to read them over out loud. If your joke is based on footage, you have to determine how to describe what's going on visually without stepping on the rhythm. You also have to describe any graphics you want made or music you need. And, if you've had a tough day, you have to avoid prefacing your jokes with "Sorry, I had a tough day." This it took me a long time to learn.