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PGR Conference Presentation

PGR Conference Presentation

My presentation at the PGR Conference at University of Liverpool

Liam Bratley

May 12, 2014
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  1. Exploring Invisible Landscapes Through The Development of Interactive Trails for

    Mobile Devices Liam Bratley Alex D. Singleton Chris Lloyd
  2. Introduction •  Summary of project and aims: •  Review the

    literature in fields related to the fundamental principles of this project; keywords include: GIS, crowd-sourcing, mobile applications, walking, cluster analysis and custom cartography. •  Review the information types and technology applicable to the participation in walking. •  Build a database of walking routes that appends data from various sources to the routes. This helps to contextualize and characterize the routes, and provides a foundation for the classification and typology of walking routes.
  3. Introduction •  Summary of project and aims: •  Use cluster

    analysis to build a GIS-based typology of walking routes. •  Learn more about the behaviour of walkers by completing a survey of a relevant population; in this case the Walkingworld community. •  Use the knowledge gained from the survey to validate research decisions made in producing the typology •  Use the knowledge gained from the survey to inform the design and implementation of a mobile application. •  Future work includes the testing and evaluation of mobile application in lab and field tests, and the development of bespoke walking cartography.
  4. Who are Walkingworld? •  Offer membership and subscription schemes for

    walking enthusiasts. •  Over 6000 walks to view and download, download is only possible with a subscription. •  Possible for new members to submit walks as well as download them. •  The newly submitted routes are then moderated and a small royalty is paid to the submitter. •  This is a very early example of a crowd sourced data model, with a slightly different business model to similar projects in the area. •  Walks consist of a series of waypoints or walk nodes. Each walk is required to have a photo, description, grid reference square and geolocation.
  5. An Example of a Walk •  This is walk ID

    number 5 from the Walkingworld database. •  There is an ordered sequence of walk nodes •  This project uses these walking routes to produce a walk route database, typology of walking routes, and a mobile application that allows searching and viewing of walks on a smartphone or tablet.
  6. Attribute Data Walking   Routes   •  Coordinates of each

    walk point Open   Data   •  In National Park/Green Belt/Area of Outstanding Natural Beauty? •  Urban/Rural Classification •  Population Density of Surrounding Area •  Altitude of walk point Derived   Data   •  Distance to public transport •  Distance to nearest pubs •  Distance to coast •  “Average Scenic Rating” WALKING     ROUTE     DATABASE   •  Distance  to   nearest  water   •  Geology  of   underlying  rock  
  7. Attribute data A"ribute   Data  type   AlDtude   ConDnuous

      Distance  to  coast   ConDnuous;  nearest  neighbour   Distance  to  water   ConDnuous;  nearest  neighbour   Scenic  or  not  score   Aggregated  score  from  the  Scenicornot  photos   nearest  to  walk  points   Distance  to  nearest  train  staDon   ConDnuous   Distance  to  nearest  bus  stop   ConDnuous   Distance  to  three  nearest  pubs   ConDnuous,  pubs  important  to  walkers   PopulaDon  density  of  the  LSOA  surrounding  walk   point   ConDnuous   Simple  geology  structure  of  rock  underlying  walk   point   Categorical  –  one  of  igneous,  limestone,   metamorphic,  mudstone,  sandstone  and  sandstone   with  mudstone   Is  the  walk  point  in  a  NaDonal  Park?   Binary   Is  the  walk  point  in  an  Area  of  Outstanding  Natural   Beauty?   Binary   Is  the  walk  point  in  a  green  belt?   Binary   Urban  rural  classificaDon  of  LA  surrounding  walk   point   Categorical  –  one  of  Major  Urban,  Large  urban,   other  urban,  significant  rural,  rural-­‐50  and  rural-­‐80   •  AUributes  in  the   formed  data  set  are  of   various  different  types   •  Cluster  analysis  that   can  handle  mixed  data   types  was  sought.   •  However,  some  results   can  be  shown  first.  
  8. Visualisation •  Now that the data is in a database,

    it can be visualised in interesting ways. •  Showing how the ‘average scenic rating’ changes with respect to altitude for walk 464, “Trekking the Hills on the Isle of Wight” •  The y-axis shows altitude, and the x-axis demonstrates each “walk point”.
  9. Visualisation Showing the average distance of each walk to an

    adjacent bus stop bus stop, in ranges of 1 Km. 70% of walks are within an average of 0 to 1 Km from a bus stop.
  10. Visualisation Same as previous slide but for railways, in larger

    ranges of 4 km to account for the longer distance between station stops.   Results are as you’d expect, with there being more bus stops than railway stations in the country.
  11. Next Steps •  Complete cluster analysis on the walking route

    database. •  The ‘k-means’ algorithm could not be used for this data set as it contained categorical variables (one example being the “Is in National Park/Green Belt/ Area of Outstanding Natural Beauty” variables). •  The ‘EM Algorithm’ was used instead of k-means, as it can handle both continuous and categorical variables and gives each variable individual treatment by assigning an appropriate statistical distribution to it, finding the likelihood function (the Expectation part in the ‘E’) and then maximizing the likelihood of the each distribution (the Maximization part), to be inputted as part of an overall distribution for the entire data set, using ‘missing’ or unobserved data to form clusters.
  12. Results •  Using BIC, the optimum value of k was

    found to be 8. However, the size of the clusters (i.e. the amount of points in each cluster) was much more evenly spread for value k=5, and this also had a very high BIC value. •  For the benefit of aesthetics, choosing appropriate names for 5 clusters of walking routes was more sensible than 8, as many of the walks will have similar attributes. •  Each route is made up of several walk points, and it is the walk points that were classified. An important point here is that it is not the routes themselves that were classified, and so routes may have some points in one cluster and other points in other clusters. •  This is not necessarily a bad thing: a walk may start near to the coast and end up atop a cliff in a National Park; and so more than one classification for an entire route would make sense.
  13. Cluster Altitude Avg Scenic Rating Dist. To Bus Stop Dist.

    To Rail Station Distance to Coast Distance to Water Dist to nearest pub Dist to second nearest pub Dist to third nearest pub Populat- ion Density 1 126.80 4.39 789.91 8515.8 4 27862. 96 1234.3 6 3891.6 6 5534.7 2 6608.7 5 0.05 2 121.64 4.35 654.76 5086.8 2 29444. 91 830.95 1985.2 9 2941.8 4 3749.7 4 0.11 3 69.06 3.54 248.56 2327.2 9 20440. 93 605.24 865.81 1327.3 4 1802.3 4 1.73 4 77.80 4.01 510.12 9586.4 9 12550. 45 1338.3 04 5090.1 1 7293.9 7 8866.6 9 0.48 5 260.60 5.46 1380.4 1 14775. 92 25563. 27 438.66 6760.4 1 9345.0 3 11073. 14 0.02 Mean values for numeric variables for each cluster
  14. Index scores for categories in each non- numeric variable by

    cluster AUribute   Cluster  1   Cluster  2   Cluster  3   Cluster  4   Cluster  5   Geology   Igneous   39.24   19.65   25.21   28.85   453.22   Limestone   138.46   72.54   54.7   114.43   107.06   Metamorphic   21.13   20.86   50.86   534.51   192.04   Mudstone   24.26   227.54   58.39   81.83   44.1   Sandstone   111.57   84.41   158.07   141.93   41.21   Sandstone  with   Mudstone   81.45   128.33   110.55   83.83   82.45   Urban  Rural   ClassificaDon   Major  Urban   2.85   94.22   513.95   52.53   0.30   Large  Urban   41.37   119.16   374.25   26.29   3.95   Other  Urban   34.11   130.35   359.70   39.95   0.18   Significant  Rural   98.16   139.87   117.1   96.69   18.8   Rural-­‐50   102.91   92.92   63.36   110.76   122.81   Rural-­‐80   120.2   83.91   27.11   110.3   142.38  
  15. Visualisation of Cluster Locations •  Clusters appear to be well

    defined geographically as well as statistically •  Clusters 1 and 5 in more rural areas, whilst 3 and 4 are more close to urban areas. •  Next: using the survey to validate the classification.
  16. Survey of Walkingworld Community •  The  next  part  of  the

     research  project  explored  the  validity  of  the  classificaDon   through  an  illustraDve  case  study.   •  Specifically,  this  involved  a  survey  that  was  sent  out  to  every  Walkingworld  member   via  its  monthly  newsleUer.   •  22  quesDons  were  asked,  and  there  was  a  total  of  237  complete  responses.  Given   that  there  is  an  (esDmated)  65,000  members,  to  find  results  that  were  within  +/-­‐10%   of  the  populaDon  mean  at  the  95%  confidence  level,  a  total  of  96  respondents  would   be  required.  To  gain  more  accuracy  (within  +/-­‐5%),  a  total  of  382  respondents  would   be  required.  Thus,  in  the  context  of  this  research,  237  is  a  reasonable  rate  of   response.   •  The  survey  included  quesDons  about  the  type  of  routes  that  the  users  were  typically   interested  in.  
  17. Behaviour of hill/mountain walkers •  Responders  who  specified  that  they

     either:     •  Liked  to  walk  serious  mountain  challenges  occasionally  (i.e.,  any  posiDve   response  to  the  quesDon:  ‘Do  you  like  to  walk  mountain  challenges?’)   •  Or  liked  to  walk  hills/moors/fells  regularly  (i.e.,  at  least  twice  a  month)   •  Were  then  cross-­‐tabulated  against  the  walking  route  classificaDon.     •  The  Walkingworld  server  provided  all  of  the  id’s  of  walks  that  survey  respondents   had  viewed  in  full,  downloaded  as  a  PDF,  or  downloaded  as  a  GPX  file.   •  Of  the  99  respondents  who  fell  into  the  ‘hill-­‐walkers’  category,  33  route  download   profiles  were  found.   •  Although  Cluster  2  has  more  views/downloads  than  Cluster  5  here,  this  may  be   because  one  parDcular  walker  has  skewed  the  results:  in  fact,  one  user  made  912   views  or  downloads  of  Cluster  2.  If  this  walker  is  ignored,  Clusters  5  and  1  have  the   most  views  and  downloads.  These  clusters  contain  walks  that  are  highest  in  alDtude,   average  scenic  raDng,  and  distance  to  the  coast.  
  18. Behaviour of hill/mountain walkers •  Although  Cluster  2  has  more

     views/downloads  than  Cluster  5  here,  this  may  be   because  one  parDcular  walker  has  skewed  the  results:  in  fact,  one  user  made  912   views  or  downloads  of  Cluster  2.  If  this  walker  is  ignored,  Clusters  5  and  1  have   the  most  views  and  downloads.     •  These  clusters  contain  walks  that  are  highest  in  alDtude,  average  scenic  raDng,   and  distance  to  the  coast,  which  correspond  to  hilly  areas.  
  19. Conclusions and Future Work •  A walking route typology has

    been created using data appended to routes. This gives the walking routes a rich, multidimensional characterization. •  This classification may be of use to various stakeholders, especially individuals searching for a walk. •  An illustrative case study was completed using a survey of the Walkingworld community •  This case study helps to validate the classification and its use to potential stakeholders. •  A mobile application that allows users to search for, download and view a walk on a map is in production, and this application will make use of the classification produced in this research project.
  20. Extra Information •  Cluster names: •  Cluster 1: Scenic Wonders

    -- Walks in Areas of Outstanding Natural Beauty •  Cluster 2: Into the Wild -- Walks in remote areas •  Cluster 3: Lowland, Coastal, Urban -- Walks close to urban areas •  Cluster 4: Urban Meadows -- Walks in and around green belt areas •  Cluster 5: Lofty Heights -- Trekking the beautiful hills in and around National Parks