Apple's autocorrect on iPhone and iPad always aims to help when you're typing a message, but it's by no means perfect, and some of the replacements it continually spews out can be frustrating.

Twenty years after the introduction of the theory, we revisit what it does—and doesn’t—explain. by Clayton M. Christensen, Michael E. Raynor and Rory McDonald Please enjoy this HBR Classic. Clayton M.

Shelby Putnam Tupper is founder and creative director of Shelby Designs Inc., a small-but-mighty, full-service, customer-obsessed design consultancy.