introduction: statistics in geography module 02. reading read chapters 1 & 2read chapters 1...
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Introduction:Introduction:Statistics in GeographyStatistics in Geography
module 02module 02
ReadingReading
• read Chapters 1 & 2read Chapters 1 & 2
Introduction:Introduction:Statistics in GeographyStatistics in Geography
Why Use Statistics?Why Use Statistics?
• help explainhelp explain• takes us beyond descriptiontakes us beyond description– idiographic vs nomotheticidiographic vs nomothetic• idiographicidiographic: relating to, involving or dealing : relating to, involving or dealing
with the individual or uniquewith the individual or unique• nomotheticnomothetic: formulating general statements or : formulating general statements or
scientific lawsscientific laws
• symbiotic relationship of the 2symbiotic relationship of the 2• nomothetic nomothetic ––>––> scientific method scientific method
Scientific MethodScientific Method
• modelmodel
• theorytheory
• laws & paradigmslaws & paradigms
Basic Terms & ConceptsBasic Terms & Concepts
• datadata
• data setdata set
• observationsobservations
• data valuedata value
Basic Terms & ConceptsBasic Terms & Concepts
• descriptivedescriptive– qualitativequalitative
• inferentialinferential– test hypothesestest hypotheses
– based on probabilities of outcomesbased on probabilities of outcomes
Basic Terms & ConceptsBasic Terms & Concepts
• statistical populationstatistical population
• samplesample
• estimationestimation
• hypothesis testinghypothesis testing
Levels of MeasurementLevels of Measurement
• nominalnominal
Levels of MeasurementLevels of Measurement
• nominalnominal
• ordinalordinal
Levels of MeasurementLevels of Measurement
• nominalnominal
• ordinalordinal
• intervalinterval
Levels of MeasurementLevels of Measurement
• nominalnominal
• ordinalordinal
• intervalinterval
• ratioratio
Levels of MeasurementLevels of Measurement
• nominalnominal least powerfulleast powerful
• ordinalordinal
• intervalinterval
• ratioratio
Levels of MeasurementLevels of Measurement
• nominalnominal
• ordinalordinal
• intervalinterval most powerfulmost powerful
• ratioratio
Levels of MeasurementLevels of Measurement
• nominalnominal least powerfulleast powerful
• ordinalordinal
• intervalinterval most powerfulmost powerful
• ratioratio
Levels of MeasurementLevels of Measurement
• nominalnominal least powerfulleast powerful
• ordinalordinal
• intervalinterval most powerfulmost powerful
• ratioratio
General Requirements for a General Requirements for a Statistical TestStatistical Test
• availabilityavailability
• reliabilityreliability
• sufficiencysufficiency
• definitiondefinition
Parametric Test or Parametric Test or Nonparametric Test?Nonparametric Test?
• parametricparametric–makes assumptionsmakes assumptions
• nonparametricnonparametric– no assumptionsno assumptions
Advantages of NonparametricAdvantages of Nonparametric
• distribution freedistribution free• works on ordinal works on ordinal (sometimes nominal)(sometimes nominal)
• easily computedeasily computed
• works on small samplesworks on small samples
• many are exact testsmany are exact tests
• generally easier to understandgenerally easier to understand
The Power of a TestThe Power of a Test
• so why use parametric?so why use parametric?–more powerfulmore powerful
• size of sample increases powersize of sample increases power
Huge Number of TestsHuge Number of Tests
• which one?which one?
• usually an easy selection processusually an easy selection process– based on nature of data, problem, based on nature of data, problem,
hypothesishypothesis
Geographic DataGeographic Data
Discussion of Geographic DataDiscussion of Geographic Data
• questionsquestions
• sourcessources
• methodmethod
• typetype
TypeType
• primaryprimary
• secondarysecondary
PrimaryPrimary
• fieldfield
• timetime
• sample designsample design
Secondary (Archival)Secondary (Archival)
• other usesother uses
• government or other government or other organizationorganization
• convenienceconvenience
• paper/CD/DVD/floppy/computer paper/CD/DVD/floppy/computer filefile
Advantages of SecondaryAdvantages of Secondary
• costcost
• timetime
• sample designsample design
Disadvantages of SecondaryDisadvantages of Secondary
• dependencedependence
• errorserrors