Blind Estimation for Planning Poker

When helping people learn Planning Poker I always ask what will happen if one person plays/says their estimate before anyone else. Many people usually spot the problem and they call it “influence.” And they’re right. Sometimes a wise person says, “but I won’t be influenced”. The science of ”anchoring“ is well known but until recently I couldn’t think of a personal example that illustrates the problem. Happily a recent trip to San Francisco solved that problem.

I was shopping for a new pair of pants. My expected price was $75 for a decent pair of khaki’s. My first stop was Hugo Boss which sold very casual khaki’s for $150. I thought, “No way! Far too much money.”  In the next few stores I saw several more pairs of pants at $100-120. But fifteen minutes after I first saw the $150 pants, I bought pair for $100 in Bloomingdales (10% discount because I’m a Canadian). I was happy to get such a bargain. After an insanely long walk back to my hotel I realized what had just happened. Seeing the $150 pants reset my price point and now I thought that was the high end and that $100 was “reasonable”. Luckily I didn’t buy two pairs, which was my original intent.

Anchoring is subtle and is it can be pernicious. One comment that really stuck with me in this area came from Dan Airely- even with everything he knows about these kinds of biases and errors he still makes these mistakes.

That is why Planning Poker estimates are done blind, no pre-conversations about the estimate.

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  • http://twitter.com/jwgrenning James Grenning

    Hi Mark

    In the first ever planing poker game, the ‘experts’ kept rehashing their numbers. The non-experts nodded, just like you would expect. The problem I was solving with planning poker at the time was to get people to show quickly when they agreed, without the influence of hearing others’ opinions, so we could move on. We could save the discussion for when we did not agree. My experience is that as soon as the discussions starts, there is little hope of stopping it soon.

  • http://twitter.com/andrewjgoddard Andrew Goddard

    James,

    I used to whistle at the team when these sort of discussions started up and called them for being “off-sides”. Do that enough and people learn appropriate/inappropriate behaviours. As the team gains experience and understanding of the influence Mark is talking about in his post they will eventually police themselves.