Abstract
We analyze optimal task assignment when a firm needs to learn the abilities of employees. When projects require collaboration between juniors and seniors and only team outputs are observable, having juniors divide their time between two projects ("junior sharing") is less informative about their abilities, but more informative about their senior teammates abilities, then having juniors devote all their time to a single project ("no sharing). In an overlapping generations model, we show that "no sharing" is more (less) attractive than "junior sharing" if the prior uncertainty about abilities is small (large) relative to exogenous shocks to team production.