Consistency and coherence
In cross-platform design, some things should be consistent. But others are better being coherent.
In London, we work on two quite different Twitter apps. One (Twitter for Tablets) is designed for mainstream users: sofas, snacking, second screens. The other (TweetDeck) is designed primarily for journalists: desktops, busy newsrooms, breaking stories.
They’re both Twitter, but they’re different Twitter. So we have to work out what should be the same, and what should flex.
We identify the atomic, inviolable units—the “tweet anatomy”, language, button styles, core destinations like DMs—and ensure these are consistent. Enforcing similar presentation and behaviour means users can rely on core functionality, and helps a Twitter user make sense of these apps when they first use them.
For other elements—navigation, interaction styles, certain transitions, advanced features—consistency would be too constraining. No need to repress valuable differentiation. (We’ve made that mistake before.) Instead, we ensure these elements are coherent. Where there’s a good reason for them to diverge—to better serve that userbase and their contexts—we let them. What matters is not that the parts are the same, but that they come together to form a unified whole.