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Re: [ai-geostats] Frightened of Spatial Autocorrelation

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  • Koen Hufkens
    Some random remarks that went through my single braincell: I would focus on the physical environment to predict the locations, but it depends on what you call
    Message 1 of 10 , Sep 2, 2004
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      Some random remarks that went through my single braincell:

      I would focus on the physical environment to predict the locations, but
      it depends on what you call an archeological site.

      A part of the place where a settlement would be created, could be
      explained by the distance from the surrounding sites. But I would think
      of it as a marginal effect until pretty recent times.

      Why do I think this:

      - If you go way back, people where selfsubstaining living communities.
      So, if commerce wasn't that big a part of their life the distance to
      other villages wouldn't matter and the choices for starting a village
      would only be dominated by physical factors.

      - In recent times the distances could become more important because of
      trade and the fact that their were more people around, that would spread
      across the land to claim their part of a living community where there
      would be some "breathing" space. That "breathing" space could be your
      clue to finding more sites. But again only if the combination of the
      social factors (preventing overcrowding and the urge to claim your patch
      of land) and the biophysical ones were in favour of the people.

      No social pressure on a community = no need to resettle, bad land = no
      way someone is going to settle there (until recent times with better
      agricultural techniques).

      A case where your technique would work is a uniform type of soil and
      topography, where the (re-)settlement of people would only be dominated
      by social factors and not so much by biophysical ones. Look at maps of
      the champagne area in France (sorry, only example I could think of).

      So, depending on the timeframe your looking at my strategy would differ.
      On old settlements I wouldn't include the distance and focus more on
      detailed biophysical data like pollen data. For recent times the SA
      approach could be interesting, because of the social aspect, but I
      wouldn't let it dominate a prediction model. You could cross check it
      with a model without the distances and known sites with a leave one out
      methode to see how good it behaves. Anyway... have fun with it...

      Cheers,
      Koen.



      On Thu, 2004-09-02 at 21:43, Kevin M. Curtin wrote:
      > Hello All,
      >
      > I’m not sure if this is the correct forum for this…but a colleague has
      > asked a question I’d like to address.
      >
      >
      >
      > This fellow wants to predict the location of archaeological sites
      > based on factors such as soil type, proximity to a water source,
      > slope, AND proximity to other archaeological sites.
      >
      >
      >
      > On proposing such a predictive model he has been challenged with, “How
      > are you going to deal with Spatial Autocorrelation”. We’re not sure
      > why SA should be a problem since we are suggesting that spatial
      > proximity is a factor in settlement location.
      >
      >
      >
      > So, do we need to test for SA and why?
      >
      >
      >
      > Thanks in advance,
      >
      > Kevin
      >
      >
      >
      >
      >
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    • Steven Citron-Pousty
      You might look at the following series of papers: http://www.nceas.ucsb.edu/~liebhold/ecography/ While the papers are written with an ecological focus,
      Message 2 of 10 , Sep 2, 2004
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        You might look at the following series of papers:
        http://www.nceas.ucsb.edu/~liebhold/ecography/
        While the papers are written with an ecological focus, settling is
        settling is settling.
        Hope they help...
        Steve

        Isobel Clark wrote:

        >Kevin
        >
        >Sounds like an ideal case for Geographically Weighted
        >Regression.
        >
        >You could use semi-variograms or spatial
        >auto-correlation to determine exactly how proximity
        >defines relationship. My only current beef with GWR is
        >the seemingly pre-defined distance weighting
        >functions. Not had much time to get into this yet, so
        >don't dump on me all you experts out there.
        >
        >I would be interested in any published results on this
        >as one of my business partners is doing similar work
        >on bronze age denmark.
        >
        >Isobel
        >http://uk.geocities.com/drisobelclark
        >
        >
        >
        >
        >
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      • Beatrice Mare-Jones
        Hello Kevin You may like to speak to David Hansen a GIS Specialist/ Soil Scientist at the USGS in Sacramento - dhansen@mp.usbr.gov He has a good paper
        Message 3 of 10 , Sep 2, 2004
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          Hello Kevin

          You may like to speak to David Hansen a GIS Specialist/ Soil Scientist at
          the USGS in Sacramento - dhansen@...

          He has a good paper "Describing GIS Applications: Spatial Statistics and
          Weights of Evidence Extension to ArcView in the Analysis of the
          distribution of Archaeological Sites in Landscape. You may know this one -
          if not you can view it at www.goscafe.com?technical_papers/Papers/paper054

          Kind regards


          Beatrice





          "Kevin M. Curtin" <curtin@...>
          03/09/2004 07:43


          To: <ai-geostats@...>
          cc:
          Subject: [ai-geostats] Frightened of Spatial Autocorrelation


          Hello All,
          I'm not sure if this is the correct forum for this?but a colleague has
          asked a question I'd like to address.

          This fellow wants to predict the location of archaeological sites based on
          factors such as soil type, proximity to a water source, slope, AND
          proximity to other archaeological sites.

          On proposing such a predictive model he has been challenged with, "How are
          you going to deal with Spatial Autocorrelation". We're not sure why SA
          should be a problem since we are suggesting that spatial proximity is a
          factor in settlement location.

          So, do we need to test for SA and why?

          Thanks in advance,
          Kevin
          * By using the ai-geostats mailing list you agree to follow its rules
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        • sebastiano
          I think that a fuzzy logic system approach is well suited for you task Some book where you can find something Principle of Geographical information Systems
          Message 4 of 10 , Sep 3, 2004
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            I think that a fuzzy logic system approach is well suited for you task
            Some book where you can find something "Principle of Geographical information Systems" Burrough and MCdonnel
            and "Fuzzy Logic in Geology", Demicco (2004)
            Bye
            Sebastiano trevisani
             At 21.43 02/09/2004, you wrote:
            Hello All,
            I’m not sure if this is the correct forum for this…but a colleague has asked a question I’d like to address.
             
            This fellow wants to predict the location of archaeological sites based on factors such as soil type, proximity to a water source, slope, AND proximity to other archaeological sites.
             
            On proposing such a predictive model he has been challenged with, “How are you going to deal with Spatial Autocorrelation”. We’re not sure why SA should be a problem since we are suggesting that spatial proximity is a factor in settlement location.
             
            So, do we need to test for SA and why?
             
            Thanks in advance,
            Kevin
             
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          • Viktoras Didziulis
            Hello, Kevin ! Predictive interpolation is a very interesting field. You may be interested in GIS applications based on Dempster-Shafer Theory. There are some
            Message 5 of 10 , Sep 3, 2004
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              Hello, Kevin !

              Predictive interpolation is a very interesting field.

              You may be interested in GIS applications based on Dempster-Shafer Theory.
              There are some online material also linked to archeology and prediction of
              archaeological sites at http://gis.esri
              com/library/userconf/proc99/proceed/papers/pap295/p295.htm
              and http://websrv5.sdu.dk/ejstrud/forskning.html

              Also IDRISI GIS has a collection of useful modeling tools for multicriteria
              analysis. It is described in manual which can be downloaded from IDRISI web
              site...

              Another subject of interest might be various AI techniques. I personally am
              experimenting with Case Based Reasoning (spatial predictions of community
              structure). There are some references and an experimental module online at
              http://www.alleco.fi/allmaps
              Currently I am rewriting the code (for the third time already :)). Still, at
              least for me it looks promising. Although currently I came to a decision
              that these 'explicit' GIS modeling techniques must be suplemented with the
              implicit' ones based on cellular automation, nearest neighbourhood or
              variograms and krigging. The reason to think so is that those 'inteligent'
              methods predict ecological niches. But in real world those niches may remain
              unoccupied. So we need an interaction of explicit top-down influence in form
              of 'niches' and implicit bottom-up influence in the form of 'growth from a
              seed'.

              Best regards
              Viktoras

              -------Original Message-------

              From: Kevin M. Curtin
              Date: 2004 m. rugs�jis 02 d. 12:44:03
              To: ai-geostats@...
              Subject: [ai-geostats] Frightened of Spatial Autocorrelation

              Hello All,
              I�m not sure if this is the correct forum for this�but a colleague has asked
              a question I�d like to address.

              This fellow wants to predict the location of archaeological sites based on
              factors such as soil type, proximity to a water source, slope, AND proximity
              to other archaeological sites.

              On proposing such a predictive model he has been challenged with, �How are
              you going to deal with Spatial Autocorrelation�. We�re not sure why SA
              should be a problem since we are suggesting that spatial proximity is a
              factor in settlement location.

              So, do we need to test for SA and why?

              Thanks in advance,
              Kevin
            • Niels Chr. Nielsen
              Isobel, Kevin and others I would be very interested as well, since my collegue (an archaeologist) and myself (geographer) are doing work on Bronze Age Denmark,
              Message 6 of 10 , Sep 3, 2004
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                Isobel, Kevin and others

                I would be very interested as well, since my collegue (an archaeologist) and myself (geographer) are doing work on Bronze Age Denmark, in the landscape of Vendsyssel. See web site http://websrv5.sdu.dk/ejstrud/forskning.html
                with paper http://websrv5.sdu.dk/ejstrud/forskning/GIS/ejstrud_wunsdorf_2001.pdf
                and http://www.humaniora.sdu.dk/kulturmiljoe (mostly in Danish)

                Niels


                Isobel Clark wrote:
                Kevin
                
                Sounds like an ideal case for Geographically Weighted
                Regression. 
                
                You could use semi-variograms or spatial
                auto-correlation to determine exactly how proximity
                defines relationship. My only current beef with GWR is
                the seemingly pre-defined distance weighting
                functions. Not had much time to get into this yet, so
                don't dump on me all you experts out there.
                
                I would be interested in any published results on this
                as one of my business partners is doing similar work
                on bronze age denmark.
                
                Isobel
                http://uk.geocities.com/drisobelclark
                
                
                	
                	
                		
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                -- 
                Niels Chr. Nielsen, M.Sc.
                Skolevej 18, Nordby
                DK-6720 Fanø
                Tlf. (+45)76121216(evening),(+45)65504152(during day)
                mobile (+45)20878568
                e-mail: niels_c_nielsen@...
                
              • Rajive Ganguli
                With ref. to the posting below (AI techniques and predictive work), we have recently done a lot of work comparing kriging and neural network performance. As
                Message 7 of 10 , Sep 3, 2004
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                  With ref. to the posting below (AI techniques and predictive work), we
                  have recently done a lot of work comparing kriging and neural network
                  performance. As an example, one of those papers (soon to show up in
                  Jo. Exp. Geol) is posted at
                  http://www.faculty.uaf.edu/ffrg/papers/nomepap_modi_revise.zip.

                  To summarize our findings, I would say there hasn't been much
                  difference in prediction performance. One or the other is marginally
                  better on any given case. An indication of the absolute performance
                  of either methods can be easily obtained from the semi-variogram:
                  lower the nugget, better both methods perform, while higher the nugget
                  the worse they both perform.

                  In the paper that is posted, both methods performed very well with NN
                  having a prediction performance (R_sq) upwards of 0.98 with very low
                  bias and kriging being 0.95.

                  Thanks,


                  Rajive Ganguli, Ph.D., P.E., C.O.I
                  Associate Professor of Mining Engineering
                  University of Alaska Fairbanks
                  ================================
                  Office: 317 Duckering Building
                  Mailing Add: Box 755800, Fairbanks, AK 99775
                  ph: 907-474-7631, fax: 907-474-6635
                  web: http://www.faculty.uaf.edu/ffrg/
                  -------------------------------------------
                  "He uses statistics as a drunken man uses lamp-posts... for support rather
                  than illumination." - Andrew Lang (1844-1912)




                  -----Original Message-----
                  From: Viktoras Didziulis [mailto:viktoras.didziulis@...]
                  Sent: Friday, September 03, 2004 12:12 AM
                  To: ai-geostats@...
                  Subject: Re: [ai-geostats] Frightened of Spatial Autocorrelation

                  Hello, Kevin ! Predictive interpolation is a very interesting field. You
                  may be interested in GIS applications based on Dempster-Shafer Theory.
                  There are some online material also linked to archeology and prediction of
                  archaeological sites at http://gis.esri
                  com/library/userconf/proc99/proceed/papers/pap295/p295.htm and
                  http://websrv5.sdu.dk/ejstrud/forskning.html Also IDRISI GIS has a
                  collection of useful modeling tools for multicriteria
                  analysis. It is described in manual which can be downloaded from IDRISI web
                  site... Another subject of interest might be various AI techniques. I
                  personally am
                  experimenting with Case Based Reasoning (spatial predictions of community
                  structure). There are some references and an experimental module online at
                  http://www.alleco.fi/allmaps Currently I am rewriting the code (for the
                  third time already :)). Still, at
                  least for me it looks promising. Although currently I came to a decision
                  that these 'explicit' GIS modeling techniques must be suplemented with the
                  implicit' ones based on cellular automation, nearest neighbourhood or
                  variograms and krigging. The reason to think so is that those 'inteligent'
                  methods predict ecological niches. But in real world those niches may remain
                  unoccupied. So we need an interaction of explicit top-down influence in form
                  of 'niches' and implicit bottom-up influence in the form of 'growth from a
                  seed'. Best regards Viktoras -------Original Message------- From:
                  Kevin M. Curtin Date: 2004 m. rugsëjis 02 d. 12:44:03 To:
                  ai-geostats@... Subject: [ai-geostats] Frightened of Spatial
                  Autocorrelation Hello All, I'm not sure if this is the correct forum for
                  this…but a colleague has asked
                  a question I'd like to address. This fellow wants to predict the location
                  of archaeological sites based on
                  factors such as soil type, proximity to a water source, slope, AND proximity
                  to other archaeological sites. On proposing such a predictive model he has
                  been challenged with, "How are
                  you going to deal with Spatial Autocorrelation". We're not sure why SA
                  should be a problem since we are suggesting that spatial proximity is a
                  factor in settlement location. So, do we need to test for SA and why?
                  Thanks in advance, Kevin
                • Volker Bahn
                  Hi Kevin, I work in the field of distribution modeling of birds and somewhat come from the other direction than most geostatistics people here on the list. In
                  Message 8 of 10 , Sep 7, 2004
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                    Hi Kevin,

                    I work in the field of distribution modeling of birds and somewhat come from
                    the other direction than most geostatistics people here on the list. In
                    ecology, we first only predicted by local conditions and habitat, then were
                    pointed to the problems of spatial autocorrelation in such an approach, then
                    tried to compensate for autocorrelation problems in statistics and only
                    lately recognized that autocorrelation is actually additional information
                    that could improve prediction. Steve already posted the most current papers
                    regarding this issue in Ecography, which helped me much
                    (http://www.nceas.ucsb.edu/~liebhold/ecography/). I would add the following
                    paper to the list:

                    Lichstein J. W., T. R. Simons, S. A. Shriner, and K. E. Franzreb. 2002.
                    Spatial autocorrelation and autoregressive models in ecology. Ecological
                    Monographs 72(3):445-463.

                    For birds it has been well documented that autocorrelation in distributions
                    are caused by autocorrelation in underlying resources. Thus, in theory, if
                    you cover ALL important predictors in your model (let's say a regular
                    regression or any other "non-spatial" method), the spatial structure in the
                    distribution is modeled implicitly by being contained in the predictors.
                    However, if you miss a predictor (which in practice will always be the
                    case), you will miss its spatial structure and the residuals of your
                    analysis will reflect this structure rendering these approaches ineffective
                    and statistically flawed. In addition, I'm trying to show in my research
                    that dispersal of individuals (meaning leaving either the birthplace or the
                    last breeding place permanently to breed elsewhere) also leads to
                    autocorrelation in distributions. This could also be the case for
                    archeological sites as there was undoubtedly some contact and exchange among
                    neighbors and this contact would have been more intense with close neighbors
                    as travel comes at a cost. Thus I would expect autocorrelation in the
                    spatial distribution of archeological sites above and beyond the
                    autocorrelation in the underlying conditions predicting archeological sites.
                    I use conditional autoregressive regression models (CAR) in Splus to model
                    bird distributions.

                    I hope this helps

                    Volker
                    _______________________________
                    Volker Bahn
                    Dept. of Wildlife Ecology - Rm. 210
                    University of Maine
                    5755 Nutting Hall
                    Orono, Maine
                    04469-5755, USA
                    Tel. (207) 581 2799
                    Fax: (207) 581 2858
                    volker.bahn@...
                    http://www.wle.umaine.edu/used_text%20files/Volker%20Bahn/home.htm


                    ----- Original Message -----
                    From: Kevin M. Curtin
                    To: ai-geostats@...
                    Sent: Thursday, September 02, 2004 15:43
                    Subject: [ai-geostats] Frightened of Spatial Autocorrelation


                    Hello All,
                    I'm not sure if this is the correct forum for this.but a colleague has asked
                    a question I'd like to address.

                    This fellow wants to predict the location of archaeological sites based on
                    factors such as soil type, proximity to a water source, slope, AND proximity
                    to other archaeological sites.

                    On proposing such a predictive model he has been challenged with, "How are
                    you going to deal with Spatial Autocorrelation". We're not sure why SA
                    should be a problem since we are suggesting that spatial proximity is a
                    factor in settlement location.

                    So, do we need to test for SA and why?

                    Thanks in advance,
                    Kevin




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