Aaron Naparstek reports
that "WNYC’s Brian Lehrer wants to know how many
SUV’s there are on your block." Apparently this is an experiment
in "crowdsourcing", and it involves Lehrer’s listeners (and Naparstek’s
readers) wandering outside at some point over the next week, counting the number
of cars vs SUVs on their block, and then leaving the results in Naparstek’s
comments section on the WNYC
website. It’s an interesting idea, but it has little empirical validity.
Why?
The main reason is that public-radio listeners and Streetsblog readers are
not an impartial group: they generally hate SUVs. When they see a lot of SUVs
on their block, they’re likely to get annoyed, and remember the Streetsblog
post, and start counting. It’s conceivable that they might even exaggerate,
either consciously or unconsciously, depending on shades of grey about what
exactly constitutes an SUV.
The readers might even find themselves walking down a block which is not their
own, see that it’s full of SUVs, and report that block, rather than
their own. And if and when they look out their window or walk down their block
and see that there are precious few SUVs on it, they’re less likely to report
that fact.
I think Naparstek’s experiment would be much more effective if he made participants
participate twice. First, they would post which specific block they were going
to count, and the specific time and day they were going to count it –
which would have to be at least 6 hours in the future. Then the second post,
conducted at the predetermined place and time, would be the actual count.