The Test Statistic
Hypothesistestinginvolvestheuseofdistributionsofknownarea,likethenormal
distribution,toestimatetheprobabilityofobtainingacertainvalueasaresultofchance.The
researcherisusuallytestingtoseeiftheprobabilitywillbelowbecausethatmeansitislikel
Steps in the Process
Makingaccurateguessesrequiresgroundwork.Thestatisticianmustdothefollowingin
ordertomakeaneducated,betterthanchancehunch:
1.
Gatherdata(numericalinformation).
2.
Organizethedata(sometimesinapictorial).
3.
Analyzethedata(usingtestsofsig
Relative Frequency Theory
Therelativefrequencytheoryofprobabilityholdsthatifanexperimentisrepeatedan
extremelylargenumberoftimesandaparticularoutcomeoccursapercentageofthetime,
thenthatparticularpercentageisclosetotheprobabilityofthatoutcome.
Forexample,i
Type I and II Errors
Youhavebeenusingprobabilitytodecidewhetherastatisticaltestprovidesevidenceforor
againstyourpredictions.Ifthelikelihoodofobtainingagiventeststatisticfromthepopulation
isverysmall,yourejectthenullhypothesisandsaythatyouhavesupportedyour