But in defense of Family Ties, it’s very hard to do exposition in a show about a family. Families, by their nature, spend a lot of time together. So it’s very hard to find a moment when family members can plausibly be telling each other something for the first time; no matter when you start the scene, it’s usually going to seem like they should know this stuff already. And exposition can’t be plausible unless there are satisfactory reasons for the audience to believe two things: one, that the character delivering the exposition would actually be saying this stuff, and two, that the other character would actually want to hear it. Family shows are okay on point two, but they have a lot of problems with point one. Which is how you get all those scenes of characters getting out of a car, talking about where they are and why they’re there. Or one-sided phone conversations where the character repeats everything the unheard party is supposedly saying (“Are you telling me that there’s a big party tonight?”).
Shows that have a workplace element in them usually have it easier, because co-workers don’t spend all their time together, so you can do a scene where the hero tells his co-workers what’s going on in his home life. And it sort of makes sense that they might not know about it already, though it doesn’t always make sense that they’d want to listen.
If you watch an episode of a show that shuttles back and forth between work and home, like The Dick Van Dyke Show or The Bob Newhart Show, you’ll notice that the exposition is often delivered in the place that is not directly related to the plot that week. If this week’s episode of The Dick Van Dyke Show is about Rob’s home life, then he’ll often deliver a lot of the exposition at work, telling Buddy and Sally what’s going on at home. Whereas if it’s a work plot, the home scenes allow Rob to bounce exposition off Laura.
Another way of doing exposition is to bring in a guest character who doesn’t know what’s going on, and have the hero explain it to him. (“You’re new in school? Well, the prom is tomorrow night…”) Or you can have a regular character who’s somewhat cut off from the rest of the cast, so that they have to tell him what’s new in their lives. Giles on Buffy the Vampire Slayer was there to deliver all the exposition about the scary monsters, but he was also there to receive exposition: because he was leading a hermetic existence in the library, Buffy could come in and tell him – and us – what was up with her life.
It also helps if you have a really clueless character, particularly an absent-minded one. Henry Blake on M*A*S*H is a great exposition machine because he tends to forget things, which means that Radar can tell him (and us) what the situation is. It wouldn’t be plausible to have Radar explain these things to someone with more on the ball – which meant that the exposition got clunkier after Colonel Potter came in – but it is plausible that he would tell Blake, because we know that Blake would in fact forget this stuff.
And then, of course, there’s the narrator, the voice-over exposition machine. Having Captain Kirk say “Captain’s Log…” and explain that week’s mission saved the writers a lot of expository dialogue. And today, narrators are everywhere, partly because of the ridiculously short running times (since lots of scenes have to be cut to get a show down to 20 minutes, a narrator allows the producers to cut those scenes while still letting the audience know what we would have seen happen if there’d been more time), but partly because it cuts down on the necessity to find ways to deliver the exposition. Actually, I think those two things – short running times and narrators – are related in some ways: it’s not just that expository dialogue is clunky and hard to write, it’s that there’s just no time for it. So you have Earl or Older Ted tell us where the characters are and why they’re there, which saves a minute or two of figuring out how they’re going to tell us.
There are other solutions that are a bit like voice-over narration, but less hackneyed. One advantage of the mock-documentary format of The Office (both versions) is that instead of the characters telling each other what’s going on, they can tell us directly, by talking to the unseen documentary filmmaker. In every episode, some of the “talking head” segments are basically straightforward exposition: this week we’re doing X, or Y is coming to visit.
Finally, if all else fails in finding ways to do the exposition, you can always do what Family Ties eventually did: bring in a little kid who can draw out the exposition by asking a lot of pointless questions.
ANDY: What's a funeral?
JENNIFER: Well, a funeral is where you go to show respect for someone who died.
ANDY: Who died?
JENNIFER: Greg, Alex's friend.
ANDY: I would like to meet him.
JENNIFER: That's gonna be tough. You see, when someone dies you never see them again.
JENNIFER: Because they're dead.
JENNIFER: Because their life's over, that's all.
ANDY: But why?
ANDY: ...Where do babies come from?