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jkizzle cutter
Joined: 29 Oct 2007 Posts: 519 Location: I.L.L.
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Posted: Wed Oct 01, 2008 3:19 pm Post subject: |
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i think i rode by the checkpoint on rose about 8 times |
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jkizzle cutter
Joined: 29 Oct 2007 Posts: 519 Location: I.L.L.
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Posted: Wed Oct 01, 2008 3:20 pm Post subject: |
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so was this just a study done by a student, or was this set up by the university to analyze needs?
the bike racks are definitely full this year... sometimes its hard to find an open or accessible spot to lock up. |
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roller d'oh!
Joined: 17 May 2008 Posts: 294 Location: duncan park
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Posted: Wed Oct 01, 2008 3:32 pm Post subject: |
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elzie5000 wrote: | As long as the number of volunteer data collectors was about the same in the previous study it shouldn't make much difference. |
I'm not sure about that. I think you want to eliminate all volunteers through some method or assumption. If you don't, you'll have no idea what kind of feedback you're creating. Imagine if a volunteer got lost finding their station and triggered 20 counts. That dweeb would inflate the count and skew the demographics. If you don't control for this type of false input, it will add up and the impact will become statistically significant.
Since we all didn't wear Transformer costumes like I did to signify that we volunteers were too cool to count, it's tough now to untangle the data. You could assume that 10% or something were false counts, but what about the demographics? You could ask all volunteers to map their routes that day and then find them in the logs. |
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taylor hipster
Joined: 30 Mar 2008 Posts: 59 Location: Woodland Park
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Posted: Wed Oct 01, 2008 6:20 pm Post subject: volunteers |
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we're not actually controlling for volunteers - like you said it would be nearly impossible for counters to know who volunteers were - I'd say I've still never seen or met about half of the people who helped us yesterday, so even fewer of the actually volunteers would have known each other. potential reasons why controlling for volunteers doesn't matter:
-at least for Tedder and I, who made all of our supervising trips by bike, I'm fairly certain that most counters didn't count us each time we passed because they knew us. even if they did, the number of trips counted from the two of us probably wouldn't have been that far off - most volunteers would have been in a similar situation.
-some volunteers didn't even ride their bikes to the count, even if they usually do ride to campus. so assuming that all volunteers triggered counts would potentially be fallacious to the point it could hurt the data from our perspective.
essentially, I just don't see the data as being corrupted. there are enough possible scenarios that would mean that any potential skewing of numbers would have happened anyways - on a given Tuesday I would probably have registered about 10 counts at various checkpoints because I make so many trips to and from campus. that's all anecdotal and far from scientific - it's just my impression that correcting for counting volunteers would probably end up being a whole lot less scientific than just saying everyone who rode by was counted. |
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roller d'oh!
Joined: 17 May 2008 Posts: 294 Location: duncan park
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Posted: Wed Oct 01, 2008 8:58 pm Post subject: Re: volunteers |
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taylor wrote: |
essentially, I just don't see the data as being corrupted. there are enough possible scenarios that would mean that any potential skewing of numbers would have happened anyways - on a given Tuesday I would probably have registered about 10 counts at various checkpoints because I make so many trips to and from campus. that's all anecdotal and far from scientific - it's just my impression that correcting for counting volunteers would probably end up being a whole lot less scientific than just saying everyone who rode by was counted. |
Hey Taylor,
Your data is not corrupted, but a gold mine. I think this is a fantastic study and I'm in no way dissing it. Hope you didn't get that impression.
61 volunteers gave up part of their day to better understand campus biking. That alone is a great achievement and frankly a testament to the enthusiasm for biking in lex.
It's my humble opinion though that if the study doesn't control for volunteers, you're cutting yourself at the knees. It's a classic example of the act of studying something changes the results. The raw count is not 100% accurate, because of the volunteers who biked and wouldn't be on campus if not for the study. The task is to filter out false counts. This makes the study more scientific not less. You can do that by assumptions (60% of volunteers biked to their station and on average triggered 5 counts each) or better yet do an explicit filter by interviewing volunteers to figure out what stations they triggered.
I could go on and on about this and please don't think I'm an asshole. You have a motherload of data that will be mined for years. Will the raw counts be public btw? I'd love to get my hands on it. |
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taylor hipster
Joined: 30 Mar 2008 Posts: 59 Location: Woodland Park
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Posted: Wed Oct 01, 2008 9:15 pm Post subject: |
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no offense taken, Boyd. I was just trying to justify the reality of our current situation, which is that we have no controls for volunteers. I understand your point that not controlling does get a bit unscientific from a methodology standpoint, but I also think that controlling for the decisions of counters as to whether or not they counted other volunteers or supervisors, as well as for the potential decrease in bike trips made (although this may be negligible) due to the large number of avid cyclists who decided to sit still for a significant portion of the day by volunteering, may be equally unscientific. my point was simply that as much scientific validity that could be gained by controlling for our own presence would probably be just as quickly lost because we a) didn't have consistency with volunteers on the matter and b) would just as quickly have to control for our own absences from the count numbers.
regardless, I appreciate everyone's help with the count - a sizable bunch of you helped out with the study, even in multiple shifts and backups (which became increasingly important by the end of the day) for unconfirmed shifts, which wasn't a convenient undertaking. I'm not sure if our raw data will be public - we actually just got our hands on the raw data from 1998 today. I'm sure that anyone who wants to see it can probably get their hands on it when the time comes, although that may not be for awhile. |
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roller d'oh!
Joined: 17 May 2008 Posts: 294 Location: duncan park
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Posted: Mon Oct 06, 2008 5:20 pm Post subject: |
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Hey Taylor,
Kudos on the "Easy Being Green" article in the fall 08 UK arts & sciences magazine, ampersand&.
You're doing some impressive work on campus environmental issues. Green it up! |
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mattypichu hipster
Joined: 27 Oct 2008 Posts: 52 Location: bike shop
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Posted: Tue Oct 28, 2008 6:21 am Post subject: |
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If a trip was made by a volunteer by bike shouldn't it have been counted? It was, after all, a bike trip on campus that could have been walked or driven...
ps I know I'm late on this but... |
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