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hzoi

"Estimate the..." -- A call for practical solutions and tasks

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There are plenty of earthcaches out there with tasks that require cache finders to estimate measurements. Personally, I think there are better ways to try and teach an earthcache lesson, which is why I've tried to change all of our earthcaches so that they don't require estimation or give cache finders an easy rule of thumb so they don't have to pull numbers out of their fourth point of contact.

 

But I digress. Sometimes measurement is needed and I don't have a ruler or thermometer or stream gauge with me. What's a guy to do?

 

I thought I would start with a couple examples of how to establish a rule of thumb. Feel free to post your own examples of ways you've fulfilled these requirements of measurement without scientific instruments. Discussion of better ways to teach earthcache lessons without tape measures is also welcome.

 

Dimensions/distance: For short measurements, a US dollar bill is just over six inches long. For longer distances with good satellite reception, a GPSr can of course be used. For longer distances without good reception, you can develop a pace count.

 

Stream flow: I didn't find any of these practical for earthcache purposes, but this page has a few techniques.

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Picturing a known distance, like a soccer field, can help with estimating distance.

 

For golfers, estimating intermediate distances comes naturally, since it is a practiced skill.

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There are plenty of earthcaches out there with tasks that require cache finders to estimate measurements. Personally, I think there are better ways to try and teach an earthcache lesson, which is why I've tried to change all of our earthcaches so that they don't require estimation or give cache finders an easy rule of thumb so they don't have to pull numbers out of their fourth point of contact.

I don't own an EarthCache, but when I see an estimate, it seems more to get a sense for whether I was actually there -- and to encourage me to actually be there mentally -- more than it's to convey any lesson. Just yesterday I did an EarthCache with a size estimate, and it was clear as soon as I walked up that was to check whether I was actually there: the picture on the webpage made me think I was going to find a sizeable boulder or even a rock wall, but it turned out to be a little 3x1' chunk of rock in a small cut next to the trail. If I hadn't been there, I wouldn't have been able to estimate the size, but the size had nothing to do with the geology lesson.

 

But I digress. Sometimes measurement is needed and I don't have a ruler or thermometer or stream gauge with me. What's a guy to do?

Unless the description says to bring an instrument, I don't take the estimates very seriously and just wing it. If the CO rejects my info because he wants it to be more accurate, that's OK with me, although that's never happened.

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Once I used a length of paracord to measure a petrified tree stump, just tied a knot at the sides, then measured it at home.

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I'm a bit concerned about the one that asks to determine/estimate the pressure of the glacial erratic upon the three rocks holding it up. Measure the cubic footage of the erratic (times given density). Measure the contact area on the three rocks below. Interesting. But is anyone going to come close to the corect answer? I doubt that the CO deletes any finds. But I would want to have a fairly accurate answer.

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Estimates of this sort are referred to by physicists (like me) as "Fermi Problems." Any well-trained physicist should be able to estimate anything to within a couple of orders of magnitude.

 

I like the estimation tasks -- they engage the brain in thinking about the problem, not just in looking up answers. As an EC owner, I don't much care what answer the finder gets; I care much more about how they thought about it to get it. Estimation is a valuable skill and I think it is neglected these days.

 

As for Harry's concern that he would want an accurate answer: that is the wrong standard for an estimate. What you want is an order-of-magnitude answer, and those can be quite valuable. In the example he gives, the pressure of a glacial erratic, an order-of-magnitude answer is quite valuable. How does the estimated pressure compare to atmospheric pressure? How deep underwater would you have to go to experience the same pressure? Is the pressure, by itself, enough to deform the rocks? etc.

 

I have never once had an Earthcache find rejected because of a bad estimate.

Edited by fizzymagic

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I have never once had an Earthcache find rejected because of a bad estimate.

 

Estimates are never my strength. I rarely deal with exact matters. Even when I golfed, I could look at a particular shot and grab a six iron if that was what was needed, but could not tell you how many yards it was to the hole. Since then, my career has been based on matters that are subject to interpretation, where there often is plenty of room for debate. So I interpret a lot. I will take a thermometer reading if one is required, a tape measurement if that is needed, or count shoe lengths if that is the unit being used. But an estimate? It's just that. My estimate should successfully complete the task even if my answer differs from the earthcache developer.

 

Not everyone may agree with that. The only time that a log has been been threatened with deletion was a task that required finders to take an elevation reading with their gpsr. It's like a question that calls for an estimate - as long as I look at the elevation my device reported, how could I not complete the task? As it turned out the owner wanted elevation readings to agree with his device, even if the latitude he allowed was smaller than the margin of error.

 

I do the best I can, yet that can leave plenty of room for debate. If my wife is with me, we will often disagree and sometimes I will give both answers. Still, I think either answer would be valid. Either is an estimate.

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I have never once had an Earthcache find rejected because of a bad estimate.

I do the best I can, yet that can leave plenty of room for debate. If my wife is with me, we will often disagree and sometimes I will give both answers. Still, I think either answer would be valid. Either is an estimate.

 

Oh, I may have been misinterpreted. My bad. I was not bragging about the quality of my estimates; I was saying that I have never logged an earthcache where the owner would reject the find based on a "bad" estimate.

 

My estimates are probably pretty bad, on average!

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Oh, I may have been misinterpreted. My bad. I was not bragging about the quality of my estimates; I was saying that I have never logged an earthcache where the owner would reject the find based on a "bad" estimate.

 

My estimates are probably pretty bad, on average!

 

I did not interpret your post as a brag, - although I was impressed with your thinking about orders of magnitude. If my estimates can withstand scrutiny then I cannot imagine that anyone should have problems.

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I have never once had an Earthcache find rejected because of a bad estimate.

I do the best I can, yet that can leave plenty of room for debate. If my wife is with me, we will often disagree and sometimes I will give both answers. Still, I think either answer would be valid. Either is an estimate.

 

Oh, I may have been misinterpreted. My bad. I was not bragging about the quality of my estimates; I was saying that I have never logged an earthcache where the owner would reject the find based on a "bad" estimate.

 

My estimates are probably pretty bad, on average!

 

My guess is that the 'estimate' is brought into the cache page to present a geological question, to qualify as an EarthCache. Best they could do, I guess.

"Estimate the height of the cliff." Well, it's manmade, and has the fencing to prevent rocks from falling. So, I measured the height of the first part of the fence, and counted how many were above. Interesting area. But how is that relevant?

I'm horrid at estimating anything. (Though Geocaching has taught me what 100' probably would be.)

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My guess is that the 'estimate' is brought into the cache page to present a geological question, to qualify as an EarthCache.

Armchair cachers. I suspect the purpose of many "estimate" questions is to confirm that the geocacher actually was at the posted location (even though all questions are supposed to be geological). It's usually difficult to find the cliff's height on the internet, while the geology of a place often appears there.

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I have never once had an Earthcache find rejected because of a bad estimate.

I do the best I can, yet that can leave plenty of room for debate. If my wife is with me, we will often disagree and sometimes I will give both answers. Still, I think either answer would be valid. Either is an estimate.

 

Oh, I may have been misinterpreted. My bad. I was not bragging about the quality of my estimates; I was saying that I have never logged an earthcache where the owner would reject the find based on a "bad" estimate.

 

My estimates are probably pretty bad, on average!

When I first met you (at a cache) your estimate with the GPSr was way off! :-) You were looking about 60 feet away while my GPSr was pointing right where the cache was.

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Best they could do, I guess.

That's my bigger point exactly -- it's not an effective way to measure learning, it's just lazy.

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I always ask - what does an estimate add to the experience of a finder? If it is to get that "WOW" moment - like - it's x times biger than a football field - or "wow" - I never realised that crystals could be so big - then great.

 

But to estimate the height of a fold - or cliff - and if you get 8 m - or 20 m - so what?

 

I really want finders to enjoy ECs = so the tasks should be fun and educational IMO.

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I always ask - what does an estimate add to the experience of a finder? If it is to get that "WOW" moment - like - it's x times biger than a football field - or "wow" - I never realised that crystals could be so big - then great.

 

But to estimate the height of a fold - or cliff - and if you get 8 m - or 20 m - so what?

 

I really want finders to enjoy ECs = so the tasks should be fun and educational IMO.

Asking for an estimate forces the seeker to look at the feature and consider what's being discussed. Between "Rock." and "Wow!", there's a middle ground of seriously considering the feature being examined by focusing on its extent instead of just glancing at it and saying "nice rock". I think that's the purpose for having estimation tasks is to get to that middle ground.

 

Earthcaches are so much more than impressing people with arbitrary extremes such as size. One interesting earthcache I did a while ago had a discussion and picture that made me expect a huge hill-sized boulder, so the estimation task insured that I'd actually gone to the site, looked at what was being discussed, and understood the object in question that told an important story about the area's geology was only 2 feet tall.

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What I like:

"Estimate this thingy..."

"Now tell me, what does that value tell you about..."

Because:

1. The estimate helps establish to some degree that the person was really there. And that is one step to getting the education -- being there (but it's not even the MOST important step, I'd argue.)

2. Then you make the estimate have some learning value. Whoa, there was 30 meters of displacement along that fault? That's a lot. Or, that boulder is only 2 meters wide, that could've been pushed into place by a few different mechanisms then...

 

A previous poster mentioned orders of magnitude. That's a very valuable tool, and a great way to gauge if an estimation is good or not.

 

While we're at it... check out the Powers of Ten movie... :)

 

--Matt

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