2010-11-16 17,280 40

The Need to Complete


Video games offer a possibility rarely had in real life - the satisfaction of being truly madly deeply 100% complete.

Beating Grand Theft Auto IV will take two weeks.  But then again, the main story line is only 68% of the game.  To reach 100% complete, you'll have to finish umpteen side quests, like chasing down 200 pigeons, and meeting random pedestrians.  It can take hundreds of hours. And the prize for getting 100% complete?  Well, there isn't one really.

In fact, 100% completions rarely lead to big juicy rewards. At most it helps unlock an easter egg.  For example, when you beat Xenosaga, you get to save "Clear Data" to the memory card.  In the sequel, this lets you equip a geriatric swimsuit. A nice gesture, but not a reward that would seem to justify hundreds of hours of toil.  So why then do so many gamers fall under the spell of compulsive completion?

Because completion is intrinsically rewarding.  Neuroscience backs this up.  It turns out that when you finish a complex task, your brain releases massive quantities of endorphins.  Through the magic of classical conditioning, you come to associate present acts of completion and progress with the pleasure and satisfaction of your past completion-induced endorphin rushes.

The "need to complete" is a powerful motivator. Properly harnessed, this observation can help you create engaging user experiences for your app or website.  And since completion is intrinsically satisfying, it isn't as gimmicky as some extrinsic rewards.

Let's look at one game-like design pattern that leverages this "need to complete" - the profile completion bar.

PROFILE COMPLETION BAR.  Last time we looked at how OkCupid onramps new users with an innovative tutorial system.  The tutorial asks new users to take a series of small steps toward a complete profile.  Progress toward this goal is communicated by a blue profile completion bar (0% to 100%).  The idea of progress is central to games.  Game theorists Salen & Zimmerman put it thusly in Rules of Play: "Without a measure of progress to give a player feedback on the meaning of his or her decisions, meaningful play is not possible."

Progress itself is the reward.  Notice how the language of the tutorial promotes this idea: "Take action X to get to 60% complete." Why would a user comply?  First, a great way to get users to do something is simply to tell them to do it.  Next, as this post claims, many users will feel rewarded when they advance progress toward 100%.  Then of course, there are users who rather loathe incompletion, but this is a glass half-full / half-empty thing. 

Progress bars must only advance, and never move back. Progress is sacrosanct in games, and there are no takebacks.  Unless you're Chutes and Ladders.  This reminds me of a design commandment I fondly attribute to my friend and Hunch colleague Caterina Fake: "Thou shalt not taketh away."  This property of in-game progress bars set them apart from the more dubious sort that you find in Windows installers and file transfer modals.  Those charlatan "progress bars" jump back, rush to 90% and stall, or make otherwise indeterminate movements.

More scavenger hunt, less like filling your taxes.  That's the ideal feel for tasks that you ask users to complete.  OkCupid's quests are fun, but the site is also inherently playful. LinkedIn, on the other hand, deals with a drier subject matter. There may be some tasks that users simply won't want to do -- such as asking another LinkedIn user for a recommendation.  Perhaps recognizing this, LinkedIn implemented a profile completion bar that has side-quest mechanics.  For example, "adding your summary"" gets you +5%.  "Asking for another recommendation" also gets you +5%.  In this design, users are able avoid certain steps and make progress in the manner of their choosing.

An extrinsic reward, just in case.  Alas, not all your users will be seduced by the need to complete.  Give them an external motive.  LinkedIn woos with this zinger: "Users with complete profiles are 40 times more likely to receive opportunities through LinkedIn." This leads us to next week's pattern - the need to eat.


Read part III of the Game-Like Mechanics series here →