CLASSIFICATION AND TABULATION OF DATA for I BSC II Semester.ppt

Bsc II semestee

1. CLASSIFICATION
AND TABULATION
OF DATA

2. Classification
Thecollecteddataorrawdataorungroupeddataarealwaysinanun
organisedformandneedtobeorganisedandpresentedinmeaningfuland
readilycomprehensibleforminordertofacilitatefurtherstatisticalanalysis.
Itis,therefore,essentialforaninvestigatortocondenseamassofdatainto
moreandmorecomprehensibleandassimilableform.
Theprocessofgroupingintodifferentclassesorsubclassesaccordingto
somecharacteristicsisknownasclassification,
Tabulationisconcernedwiththesystematicarrangementandpresentationof
classifieddata.Thusclassificationisthefirststepintabulation.
Eg:Lettersinthepostofficeareclassifiedaccordingtotheirdestinationsviz.,Delhi,
Madurai,Bangalore,Mumbaietc.,

3. ObjectsofClassification
Thefollowingaremainobjectivesofclassifyingthedata:
1.Itcondensesthemassofdatainaneasilyassimilableform.
2.Iteliminatesunnecessarydetails.
3.Itfacilitatescomparisonandhighlightsthesignificantaspectof
data.
4.Itenablesonetogetamentalpictureoftheinformationandhelps
indrawinginferences.
5.Ithelpsinthestatisticaltreatmentoftheinformationcollected.

4. Types of classification
Statisticaldataareclassifiedinrespectoftheircharacteristics.
Broadlytherearefourbasictypesofclassificationnamely
a)Chronologicalclassification
b)Geographicalclassification
c)Qualitativeclassification
d)Quantitativeclassification

5. a)Chronologicalclassification:Inchronological
classificationthecollecteddataarearrangedaccording
totheorderoftimeexpressedinyears,months,weeks,
etc.,Thedataisgenerallyclassifiedinascendingorder
oftime.
b)Eg:
The estimates of birth rates in India during 1970 –76 are
Year 1970 1971 1972 1973 1974 1975 1976
Birth Rate 36.8 36.9 36.6 34.6 34.5 35.2 34.2

6. b)Geographicalclassification:Inthistypeofclassificationthe
dataareclassifiedaccordingtogeographicalregionorplace.For
instance,theproductionofpaddyindifferentstatesinIraq,production
ofwheatindifferentcountriesetc.,
Eg:
Country America China Denmark France Iraq
Yield of wheat 1925 893 225 439 862
in (kg/acre)

7. c)Qualitative(categorical)classification:Inthistypeof
classification,dataareclassifiedonthebasisofsameattributesor
qualitylikesex,literacy,religion,employmentetc.,
Suchattributescannotbemeasuredalongwithascale.
Eg:ifthepopulationtobeclassifiedinrespecttooneattribute,say
sex,thenwecanclassifythemintotwonamesthatofmalesand
females.
Similarly,theycanalsobeclassifiedinto‘marriedor‘single’onthe
basisofanotherattribute‘maritalstatus’.

8. Thuswhentheclassificationisdonewithrespecttoone
attribute,whichisdichotomousinnature,twoclassesare
formed,onepossessingtheattributeandtheothernot
possessingtheattribute.Thistypeofclassificationis
calledsimpleordichotomousclassification.

9. d)Quantitative(numerical)classification:Quantitative
classificationreferstotheclassificationofdataaccordingtosome
characteristicsthatcanbemeasuredsuchasheight,weight,etc.,
Eg:thegroupofchildrenmaybeclassifiedaccordingtoweightas
givenbelow.
Weight (in kg) No of children
5-10 50
10-15 200
15-20 260
20-25 360

10. PRIMARYRULESOFCLASSIFICATION
Theprocessofarrangingdataingroupsandclasses
accordingtotheirsimilarattributesisanimportanttask
forwhichmanyimportantconsiderationshavetobetaken
intoaccount.
i.Thenumberofclassesshouldnotbeexcessive.
ii.Thereshouldnotbeanyambiguityinthedefinitionof
classes.

11. iii.Alltheclassesshouldpreferablyhaveequalwidthorlength.
iv.Magnitudeoftheclassintervalsshouldbeasfaraspossible
inmultiplesof5like10,15,20,25etc.
v.Theclassintervalsshouldasfaraspossibleisofequalsize.
vi.Theclassificationmustbesuitablefortheobjectofinquiry.
vii.Theclassificationshouldbeflexibleanditemsincludedin
eachclassmustbehomogeneous.

12. Tabulation
Tabulationistheprocessofsummarizingclassifiedorgroupeddata
intheformofatablesothatitiseasilyunderstoodandaninvestigator
isquicklyabletolocatethedesiredinformation.
Atableisasystematicarrangementofclassifieddataincolumnsand
rows.
Tabulationreferstoalogicaldatapresentation,whereinrawdatais
summarizedanddisplayedinacompactform,i.e.instatisticaltables.
Inotherwords,itisasystematicarrangementofdataincolumnsand
rows,thatrepresentsdatainconciseandattractiveway.

13. Thus,astatisticaltablemakesitpossibleforthe
investigatortopresentahugemassofdatainadetailed
andorderlyform.
Itfacilitatescomparisonandoftenrevealscertain
patternsindatawhichareotherwisenotobvious.
ClassificationandTabulation,asamatteroffact,arenot
twodistinctprocesses.Actuallytheygotogether.

14. MajorObjectivesofTabulation
1.Tosimplifythecomplexdata
2.Tofacilitatecomparison
3.Toeconomizethespace
4.Todrawvalidinference/conclusions
5.Tohelpforfurtheranalysis

15. DifferencesBetweenClassificationandTabulation
Theprocessofarrangingdataintodifferentcategories,on
thebasisofnature,behavior,orcommoncharacteristicsis
calledclassification.
Aprocessofcondensingdataandpresentingitinacompact
form,byputtingdataintostatisticaltable,iscalledtabulation.
Classificationofdataisdoneafterdatacollectionprocessis
completed.Ontheotherhand,tabulationfollowsclassification.

16. Dataclassificationisbasedonsimilarattributesandvariablesofthe
observations.Conversely,intabulationthedataisarrangedinrows
andcolumns,inasystematicway.
Classificationofdataisperformedwiththeobjectiveofanalysing
datainordertodrawinferences.Unliketabulation,whichaimsat
presentingdata,toensureeasycomparisonofvariousfigures.
Inclassification,dataisbifurcatedintocategoriesandsub-
categorieswhileintabulationdataisdividedintoheadingsandsub-
headings.

17. CONTENTSOFATABLE
i.Tablenumber:Eachtableshouldbenumberedshouldbeeasy
identificationandfuturereference.
ii.Title:Everytableshouldhaveatitlewhichisgenerallygivenat
thetopofthetableinthecenter.
iii.Captions:Acaptiongenerallyhasamainheadingandanumber
ofsmallsubheadings.
iv.Stubs:Itreferstotheheadingsofthehorizontalrowsandreturn
onthelefthandsideoftherow.

18. v.Body:Itcontainsthestatisticaldatawhichhavetobepresented.
vi.Headnote:Itreferstothedatacontainedinthemajorpartofthe
tableanditisplacedbelowthetitleofthetable.
vii.Footnote:Footnotesaregivenbelowthetableandaremeantto
clarifyanythingwhichisnotclearfromtheheading,title,stubs
andcaption.