geographic data science - lecture iiidarribas.org/gds15/slides/lecture_03.pdf · 2016. 2. 19. ·...

Post on 30-Aug-2020

6 Views

Category:

Documents

0 Downloads

Preview:

Click to see full reader

TRANSCRIPT

GeographicDataScience-LectureIII(Geo-)Visualization

DaniArribas-Bel

TodayVisualizationWhatandwhyHistoryExamples

GeovisualizationWhat"Amapforeveryone"Dangersofgeovisualization

Visualization

"Datagraphicsvisuallydisplaymeasuredquantitiesbymeansofthecombineduseofpoints,lines,acoordinatesystem,numbers,

symbols,words,shading,andcolor."TheVisualDisplayofQuantitativeInformation.EdwardR.Tufte.

AbitofhistoryMaps

AbitofhistoryMaps-->DataMaps(XVIIth.C.)

AbitofhistoryMaps-->DataMaps(XVIIth.C.)-->Timeseries(1786)

AbitofhistoryMaps-->DataMaps(XVIIth.C.)-->Timeseries(1786)-->

Scatterplots

AbitofhistoryMaps-->DataMaps(XVIIth.C.)-->Timeseries(1786)-->

ScatterplotsSurprisinglyrecent:1750-1800approx.(muchlaterthanmanyotheradvancesinmathandstats!)WilliamPlayfair's"lineararithmetic":encode/replacenumbersintablesintovisualrepresentations.Otherrelevantnamesthroughouthistory:Lambert,Minard,Marey.

VisualizationTheVisualDisplayofQuantitativeInformation.EdwardR.Tufte.Byencodinginformationvisually,theyallowtopresentlargeamountsofnumbersinameaninfulway.Ifwellmade,visualizationsprovideleadsintotheprocessesunderlyingthegraphic.

Learningbyseeingtime...

Timeseries[ ]XVIIIth.Cent.-PytometriebyJ.HLambertSource

Barchart[ ]Playfair'sbarchartinTheCommercialandPoliticalAtlas(1786)Source

Abstractlineplot[ ]Lambert-Evaporationrateagainsttemperature,1769Source

Minard-Napoleonarmymap(XIXth.Cent.)

[ ]"Itmaywellbethebeststatisticalgraphiceverdrawn"(E.R.Tufte)Source

Geovisualization

Tufte(1983)"Themostextensivedatamaps[...]placemillionsofbitsof

informationonasinglepagebeforeoureyes.Noothermethodforthedisplayofstatisticalinformationissopowerful"

MacEachren(1994)"Geographicvisualizationcanbedefinedastheuseofconcretevisualrepresentations--whetheronpaperorthroughcomputerdisplaysorothermedia--tomakespatialcontextsandproblemsvisible,soastoengagethemostpowerfulhumaninformation

processingabilities,thoseassociatedwithvision."

GeoVisualizationEndgoalisnottoreplacethehumanintheloop,buttoaugmenther/him.Augmentationherecomesthroughengagingthepatternrecognitioncapabilitiesthatourbraininherentlyhas.Combines:TraditionalmapsStatisticalmapsStatisticaldevicesofotherkind(charts,scatterplots,etc.)

Differentrolesintheanalysisprocess...

AmapforeveryoneMapscanfulfillseveralneedsDependingonwhichonewewanttostress,thebestmapwilllookverydifferentMacEachren&Kraak(1997)identifythreemaindimensions:

KnowledgeofwhatisbeingplottedTargetaudienceDegreeofinteractivity

Un/known:fastandslowmaps

Fastmaps[ ]Source

Audience:easyandhardmaps

Interaction:oneormanymapsinone

Staticmap

Interactivemap

Mapcreatedby darribasbel

CENTERS2010

MSAS

Visiblelayers 2

DangersofGeoVisualization

Howtoliewithmaps

HowtoliewithmapsThehumanbrainissogoodapickinguppatterns...

HowtoliewithmapsThehumanbrainissogoodapickinguppatterns......thatitfindsthemevenwheretheydon'texist!

HowtoliewithmapsThehumanbrainissogoodapickinguppatterns......thatitfindsthemevenwheretheydon'texist!Patternicity(Shermer,2008)Thetendenceytofindmeaningfulpatternsinmeaninglessnoise

HowtoliewithmapsThehumanbrainissogoodapickinguppatterns......thatitfindsthemevenwheretheydon'texist!Patternicity(Shermer,2008)Thetendenceytofindmeaningfulpatternsinmeaninglessnoise

Apophenia(Konrad,1958)Theexperienceofseeingpatternsorconnectionsinrandomormeaninglessdata

Twitterclusters

Howtobetruthfulwithmaps"Withgreatpowercomesgreatresponsibility"

Howtobetruthfulwithmaps"Withgreatpowercomesgreatresponsibility"

Statisticstotherescue!!!

Howtobetruthfulwithmaps"Withgreatpowercomesgreatresponsibility"

Statisticstotherescue!!!ComplementandenhancevisualsHelpdisentanglingtruefromspuriouspatterns(a.k.a.identifyingthe"Jesusonthetoast")Reciprocity:GeoViscanalsoenhancestatisticsandmakethemmoreuseful

StatisticsforTwitterclusters

RecapitulationVisualizationofstatisticaldataisafairlyrecentphenomenon.Itspowercomesfromengagingandaugmentingthehumanintheloop,ratherthanreplacingher/him.Itspowercanbemisused,buttherearemethodstolimitthisrisk.

GeographicDataScience'15-Lecture3by islicensedundera

.

DaniArribas-BelCreativeCommonsAttribution-NonCommercial-

ShareAlike4.0InternationalLicense

top related