Biostatistics Data

Explanation about Primary and Secondary Data.

1. Dr. M. MARIAPPAN
M.Sc., M.Phil., M.Ed., Ph.D.
Assistant Professor,
Department of Zoology,
Government Arts College,
Melur–625 106

2. Dataisacollectionofobservationsexpressed
innumericalfigures.
DATA
NATURE
OF
DATA
TIME SERIES DATA
SPATIAL DATA
SPACIO-TEMPORAL DATA

3. Itisacollectionofasetofnumericalvalues,
collectedoveraperiodoftime.
Thedatamighthavebeencollectedeitherat
regularintervalsoftimeorirregularintervals
oftime.
YEARS
GAIN
(Rs.)
2014 50,000
2015 75,000
2016 85,000

4. If the data collected is connected with that of
place, then it is termed as spatial data.

5. Ifthedatacollectedisconnectedtothetime
aswellasplacethenitisknownasspacio
temporaldata.
State
Population
2001 2011
Tamil Nadu 4,82,97,4565,56,38,318
Andhra Pradesh5,34,03,6196,63,04,854
Kerala 2,54,03,2172,90,11,237

6. CATEGORIES OF DATA
PRIMARY SECONDARY
PRIMARY DATA
Thedatacollectedforthefirsttimecalled
PrimaryData.
Thesedataarecollecteddirectlyfromthe
fieldofenquiry.

7. Thesearerawdatainoriginalnatureand
directlycollectedfrompopulation.

8. Itisaccurateandreliable.
Itconsumesmoremoneyandtime.
Theprimarydatamaybecollectthrougheither
bycompleteenumerationorsamplingsurvey
methods.

9. SECONDARY DATA
Thedataobtainedfromalreadycollecteddata
iscalledSecondaryData.

10. Thesearenumericalinformationwhichhave
beenalreadycollectedbysomeagencyfora
specificpurposeandaresubsequently
compiledfromthatsourceforapplicationin
differentconnection.
Itisnotreliable.

11. COLLECTION OF
DATA
Theprocessofgettingvaluesandfactsfrom
anobservationorexperimentiscalled
CollectionofData.
INVESTIGATOR
ENUMERATOR
RESPONDENTS

12. Direct Personal Interview
Indirect Oral Interviews
Information from
Correspondents
Questionnaires Sent -Mail
Schedules Sent -Investigators

13. Theinvestigatorpersonallymeetsthemandasks
questionstogatherthenecessaryinformations.
Itisthesuitablemethodforintensiveratherthan
extensivefieldsurveys.

14. Originaldataiscollected.
Reliableinformationisobtained.
Thereisuniformityinthecollectionof
information.
Thismethodisflexiblebecausetheinvestigator
canusehisinfluenceanddifferenttechniquesas
thesituationdemands.
Themethodyieldsmoreaccurateresults.
Itcanbemostusefulwhentheareaof
investigationisverysmall.

15. Thismethodisunsuitablewhentheareaof
investigationislarge.
Itismoreexpensiveandtime-consuming.
Thechancesofpersonalbiasaremore.

16. Underthismethodtheinvestigatorcontacts
witnessesorneighboursorfriendsorsomeother
thirdpartieswhoarecapableofsupplyingthe
necessaryinformation.
Thismethodispreferrediftherequiredinformation
isoncauseoffireortheftormurderetc.,
Ifafirehasbrokenoutacertainplace,thepersons
livinginneighborhoodandwitnessesarelikelyto
giveinformationonthecauseoffire.

17. Itcanbeusedwhentheareaofinvestigationislarge.
Itisasimpleandconvenientmethodofinvestigation.
Itiseconomicalandsavestime,moneyandlabour.
Morecomplexdatacanalsobeanalyzed.
Itispossibletoobtaincompleteandadequate
informationregardingtheenquiry.
Theresultsmaynotalwaysbetrueandaccurate.
Theinformantsmaynotbeseriousinfurnishingthe
properrepliesandhencedegreeofaccuracycanbe
affected.

18. Theinvestigatorappointslocalagentsor
correspondentsindifferentplacesandcompilesthe
informationsentbythem.
InformationstoNewspapersandsomedepartments
ofGovernmentcomebythismethod.

19. Itischeapandappropriateforextensive
investigations.
Itisusefulwheretheinformationisneededfrom
timetotime.
There is lack of originality in data.
The information can be biased.
Degree of accuracy is generally very low.
Information made available may be out-of-date.
There may not be uniformity in the collected data.

20. Underthismethodalistofquestionsispreparedand
issenttoalltheinformantsbypost.
Thelistofquestionsistechnicallycalled
questionnaire.
Acoveringletteraccompanyingthequestionnaire
explainsthepurposeoftheinvestigationandthe
importanceofcorrectinformationsandrequestthe
informantstofillintheblankspacesprovidedandto
returntheformwithinaspecifiedtime.
Thismethodisappropriateinthosecaseswherethe
informantsareliteratesandarespreadoverawide
area.

21. Itisrelativelycheap.
Itispreferablewhentheinformantsarespreadover
thewidearea.
Itisnotpossibletodeterminethedegreeofaccuracy
ofdata.
Informationmaybebiased.
Informantsmaynotliketoprovidewritten
information.
Ifthequestionnaireiscomplex,itmaynotbe
responded.

22. Underthismethodenumeratorsorinterviewerstake
theschedules,meettheinformantsandfillingtheir
replies.
Ascheduleisfilledbytheinterviewersinaface-to-
facesituationwiththeinformant.Aquestionnaireis
filledbytheinformantwhichhereceivesandreturns
bypost.
Itissuitableforextensivesurveys.

23. Itcanbeadoptedeveniftheinformantsare
illiterates.
Answersforquestionsofpersonalandpecuniary
naturecanbecollected.
Non-responseisminimumasenumeratorsgo
personallyandcontacttheinformants.
Theinformationscollectedarereliable.The
enumeratorscanbeproperlytrainedforthesame.
Itismostpopularmethods.

24. Itisthecostliestmethod.
Extensivetrainingistobegiventotheenumerators
forcollectingcorrectanduniforminformations.
Interviewingrequiresexperience.Unskilled
investigatorsarelikelytofailintheirwork.

25. Collectionofprimarydatabyframingaschedulesor
distributingandcollectingquestionnairesbypostisless
expensiveandcanbecompletedinshortertime.
Theinformationcollectedforprimarydataismere
reliablethanthesecondarydata.
Thecollectionofdatabythemethodofpersonalsurvey
ispossibleonlyiftheareacoveredbytheinvestigatoris
small.
Collectionofdatabysendingtheenumeratorisbound
tobeexpensive.
Careshouldbetakentwicethattheenumeratorrecord
correctinformationprovidedbytherespondents.

26. Published Sources
Unpublished Sources

27. Reportsandofficialpublicationsof
InternationalbodiessuchastheInternational
MonetaryFund,InternationalFinance
CorporationandUnitedNationsOrganisation.
CentralandStateGovernmentssuchasthe
ReportoftheTandonCommitteeandPay
Commission.
Semi-officialpublicationofvariouslocalbodies
suchasMunicipalCorporationsandDistrictBoards.

28. Privatepublications-suchasthepublicationsof–
Tradeandprofessionalbodiessuchasthe
FederationofIndianChambersofCommerceand
InstituteofCharteredAccountants.
Financialandeconomicjournalssuchas
‘Commerce’,‘Capital’and‘IndianFinance’
Annualreportsofjointstockcompanies.
Publicationsbroughtoutbyresearchagencies,
researchscholars,etc.

29. Allstatisticalmaterialisnotalwayspublished.
Therearevarioussourcesofunpublisheddatasuch
asrecordsmaintainedbyvariousGovernmentand
privateoffices,studiesmadebyresearchinstitutions,
scholars,etc.