Olaf Witkowski is the Chief Scientist at Cross Labs, which aims to bridge the divide between intelligence science and AI technology. A researcher of artificial life, Witkowski started in artificial intelligence by exploring the replication of human speech through machines. He founded Commentag in 2007, and in 2009 moved to Japan to continue research, where he first became interested in artificial life. In his own words, Witkowski says, "artificial intelligence means that you are trying to copy human intelligence as best as possible. Artificial life says, okay, that's good, but let's try to understand human intelligence and recreate it from the fundamental knowledge we have acquired. It's a bit like the Richard Feynman quote: what I cannot create, I do not understand."

"She was like, 'You're not your normal, cheery, bubbly self,' " Mr. Witkowski said. " 'You're not using exclamation points.' " She told him she felt his emails came off as more demanding than usual. "I didn't really know how to react," he said. Exclamation points are stressing people out. Years of rampant use have both diluted the punctuation mark's meaning and inflated its significance.

The most prominent way to establish trust in online markets such as eBay are reputation systems that publish buyer feedback about a seller's past behavior. These systems, however, critically rely on assumptions that are rarely met in real-world marketplaces: first, it is assumed that there are no reporting costs and no benefits from lying so that buyers honestly report their private experiences. Second, it is assumed that every seller is long-lived, i.e. will continue to trade on the marketplace indefinitely and, third, it is assumed that sellers cannot whitewash, i.e. create new accounts once an old one is ran down. In my thesis, I address all of these assumptions and design incentive-compatible trust mechanisms that do not rely on any of the aforementioned assumptions. Moreover, I focus on designs that minimize common knowledge assumptions with respect to the players' valuations, costs and beliefs.