From the ABC 7 Weather team

80° days: Recency and decisions

April 8, 2013 - 05:01 PM
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Decisions and recent weather

Today was our first 80° day of the year. Just about spot on to our "average" date of the first 80° day which is April 7th.   Our poll on when you thought the first 80° would happen has been up since very late March.  Look at the poll from Saturday before a confident forecast of 80°.


The climatological average high May 31 is 80.  But more than 10% thought the first 80° day would happen even later than the date with an average high of 80°. .  So why did so many of us (90% of us) think or guess the first 80° WOULD NOT happen in the first week of April?  I think it has to do with something scientists and psychologists who study behavior call "recency bias" .  A bias due to recent observations.  The bias or tendency to place more emphasis on recent events than events in the more distant past.  March 2013 was much cooler than average, 13° colder than the record warm March 2012.  March 2013 didn't even have a single 70° day and ended with a very chilly pattern.  This pattern would sure continue based on recent history . . .recency bias.  Some of us probably thought the first 80° day wouldn't come until late May or June after the weather pattern we experienced this March.  We really have to be careful of this recency bias in making weather related decisions during dangerous weather.  A tornado, flash flood, damaging winds haven't happened here recently (or ever in a lifetime) so it won't happen.   Tip our poll on the side and it is a little bit similar to a "normal" distribution.  


That is a distribution of responses (were they random guesses?) that peaked around the center and fall off on either side.  


What if we thought, or guessed, the "correct" answer must be the midpoint of the choices.  Other biases (such as conformation bias) sure enter our thinking.  But that's how we (scientists are human also) think about issues such as climate change, social issues, and political commentary.  Try not to be too biased : >) Next year we'll try again.

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