Speed vs. Accuracy when creating POI files

John
Do you really need to ask that question?

There is nothing more aggravating than inaccurate POI files. Keep working on your accuracy it's much appreciated by all.

It takes a long long time to thoroughly vet the coordinates of a POI.
Perhaps you could spend a "reasonable" time verifying the POI. Then, if in doubt regarding the specific location, add a note as a comment.
The file is thus made available much quicker, you are less frustrated and users are aware of potential problem. Hopefully they will also send you an update of the data.

You are doing exactly what many are doing by double checking thru google. Do what you can and let the POI community know to inform you of any known mistakes in your file. Yes accuracy is best but some locations are hard to pinpoint. Never trade time over accuracy.

Start small grow larger... as in life!

If you're off even half a block, and in that block there are strip malls all over, it's annoying to have to hunt for a POI.

Isn't accuracy why we have GPS'? Isn't that why we prize them?

Would you rather hunt for the POI within half a block, or not have the POI at all?

You're doing what everyone should do. Verify, verify, verify!

There are many things that can make the geocoding wrong. The calculations for a street address use an algorithm and commercial and industrial locations can be especially bad, because the business lot size can vary and the algorithm can easily miscalculate the location.

I've had other cases where the start and end numbers of the street are actually reversed, compared to what the gps has in it's database. I've seen that in a few cases, especially on crescents.

I often find I have to look at the business' own website to figure out where they say they are. I've found they can often be wrong, because they just let Google Maps show the location. If the GPS is wrong, good chance Google Maps is wrong.

Keep up the good work.

I'd much rather be on location happy than play a game of "is it around here or not?". I found it took far longer to put together my POI file then I'd expected due to inaccurate directions and coordinates provided by the actual businesses I was trying to reference. So my vote is for a little extra effort when making a POI list.

I second Juggernaut's thought. If we wanted to get to "the neighborhood" of a POI, we could just phone the place and ask for directions. I have done that and got lost many times.

Accuracy is especially pertinent when you are not in your home location and do not have any idea of the nearby landmarks. If someone said "it's near the Walmart", that isn't at all helpful if I don't know where the Walmart is.

Someone has spoken of strip malls and the problems they often present when they are not "on the road" on which you would be traveling. I like it when the POI gets as close to the door as possible. Some establishments are very small in size footprint and it is hard to find them even when you know approximately where they are.

Also, I would hope that a new POI file has been sent thru the accuracy checker (just after it is uploaded) so there is not a problem with someone not being able to use POILoader because of some typo error. I have read too many posts here on someone thinking they have done something wrong or that POILoader is failing when all that is wrong is some entry in the POI file itself.

Please keep up the good work - all those who furnish POI files. And, be as accurate as possible.

Accuracy is of key importance. However, be careful when trying to pin down a location in a mall or plaza. I had gone to extra effort to define the coordinates to get the proper mall entrance for one POI, the address only got me as far as a road on the other side of the mall. However, my refined and "improved" coordinates ended up routing me to an exit ramp near the mall but stopping there right in the middle of the street on the ramp! Sure enough, this was closer as the crow flies to the coordinates that I had for the POI, but it was impractical to park on the exit ramp and there was a high fence between the ramp and the POI. Since the GPS didn't route traffic through the parking lot it turned out better to just use the street address coordinates than to try to get fancy and route the user closer.

Reads like I'm in the minority of many to one. Still, I'm very glad to have the Garmin POI file, even though it fails to meet the accuracy requirements that most seem to think essential. Many times I have had to look up and down the street or drive through a plaza. Never much of a problem, Certainly I find it far easier than trying to find a store, hotel, etc., that isn't listed at all!
Even though you know the accurate coordinates, this may not help that much. The garmin will only direct you to the point on the road nearest the POI. If it's in a mall, you may still have to find the mall entrance and drive around the mall. My 855 generally shows mall as wide open spaces, not much help in driving around them.
Would I like 100% accurate coordinates? Of course I would, but I'm prepared to compromise on perfection to get useful, timely POIs, more frequently.
Just goes to show that different folks have different strokes.

FWIW I'm with you NOT.

I prefer an accurate location but if the best available after a reasonable amount of work is on the same block face, good enough. Hopefully someone reports the exact co-ordinates from their GPS at the first opportunity.

Having argued in a post a few earlier for accuracy, I think you are on target when suggesting that there are some "locations" where "good enough" is warranted.

What would be helpful would be for all of us to try to identify those situations when the true "best that can be done" us to get the GPS unit to a place where the establishment can be seen.

What does this mean in practice? Well, in the situation you cite, one could note it and spend a little time trying to decide what coordinates would have produced the best routing. The ExtraPOIEditor has map tools to let you find a road intersection or address to do just that. Simulation mode would check it out. A note to the POI maintainer would solve the problem for those who come after.

There are times when you do your best, but the google maps and navteq data just don't help. I always try and include a phone number and street address so that if my "point" is off, the user has other resources to help "tune" in the final location. Many times (getting better every month) some of the rural places in kansas don't have the detailed google map view to be of much help when fine tuning coordinates.

Often I find that you get no thanks for your good locations, but you will get negative feedback for sloppy work. You may not be able to tell a store exactly, but if the coordinates are in a neighborhood of houses - fix the error please...

Daniel

I agree that an accurate poi should be the goal, but I'd much rather have a phone number than exact to-the-doorstep coords.

Some think that only personally visited & verified pois should be in a file, but businesses can and do disappear overnight so that's not foolproof either.

I'd much rather be in the ballpark and have a local phone number for verification than go out of my way to a different poi because an accurate aerial view wasn't available and the poi wasn't included (so long as the source info was reliable and at least some effort was made to ensure the coords weren't in a farmer's field or lake).

That's a tough question, but I would answer that I'd rather not have the POI. Half a block is a lot of area in most cities. Plus, who knows if the POI is off half a block or half a mile.

Thanks for the replies everyone. I'll definitely stick to accuracy even if its slower although the most annoying thing about trying to get everything right is that every so often you have a location where even when you have the exact address and postal code for it, for some reason you still can't find the place.

Sometimes its a block or two off and other times could be wayyyyy off and then it takes you FOREVER to try and locate the place.

One thing I have noticed though is for large projects that involved hundreds or even thousands of pois, is that its tough to get every single poi completely accurate and I can understand why.

I was passing a Taco Bell over the weekend and noticed that it was at least a couple of blocks off from the actual location, but with literally thousands of locations, it would be pretty damn hard to check every single one unless you had help.

So yeah, while I do want best accuracy possible, I just wish there was a faster way of doing things though.