Pemilihan subyek penelitian: spesifikasi & samplingIstilah dasar dan konsep- populasi target dan aksesibilitas- generalisasi hasil-hasil penelitian-tahap-tahapan dalam rancangan protokol untuk mendapatkan - subyek penelitianSpesifikasi- pemantapan kriteria inklusi- pemantapan kriteria ekslusi- pemilihan populasi aksessibilitasSampling- sampling probabilitas- sampling nonprobabilitas- Kesimpulan pemilihan opsi rancangan sampling

Pemilihan subyek penelitian: spesifikasi & sampling (sambungan)Rekrutmen- tujuan rekrutmen- mempertinggi angka respon- pendekatan rekrutmen umum

Ikhtisar kesalahan (error) dalam pemilihan subyek penelitian.-rancangan error- implementasi error

Summary of how research worksTRUTH INTHE UNIVERSE

RESEARCHQUESTION

TRUTH INTHE STUDY

STUDY PLAN

FINDING INTHE STUDY

ACTUAL STUDY

Targetpopulation

Phenomenaof interestIntendedsample

IntendedvariablesActualsubjects

Actual measurementSRandom &systematicerrorinferinferRandom &systematicerrorRandom &systematicerrordesignimplementINTERNALVALIDITYEXTERNALVALIDITY

Choosing the research question and designing the study planTRUTH INTHE UNIVERSE

RESEARCHQUESTION

TRUTH INTHE STUDY

STUDY PLAN

FINDING INTHE STUDY

ACTUAL STUDY

Targetpopulation

Phenomenaof interestIntendedsample

IntendedvariablesActualsubjects

Actual measurementSinferinferRandom &systematicerrorINTERNALVALIDITYEXTERNALVALIDITYERRORERROR TRUTH IN THE TRUTH IN UNIVERSE THE STUDY

RESEARCH STUDY QUESTION PLANERRORERRORinferdesignimplement

Choosing the study subjects that represent the populationTRUTH INTHE UNIVERSE

RESEARCHQUESTION

TRUTH INTHE STUDY

STUDY PLAN

FINDING INTHE STUDY

ACTUAL STUDY

Targetpopulation

Phenomenaof interestIntendedsample

IntendedvariablesActualsubjects

Actual measurementSinferinferINTERNALVALIDITYEXTERNALVALIDITYERRORERRORERRORERRORdesignimplementTargetpopulationIntendedsampleActualsubjects

Inferences in generalizing from the study subjects to the accesible andtarget populations using a finding from the Framingham studySTUDY PLAN

RESEARCH QUESTION

ACTUALSTUDYActualsubjects

Ass betweenHyp & CHDobsered inthe actual ofFraminghamadultsIntendedsample

Same assocexist in the designed sampleFraminghamadultsTargetpopulation(GENERALIZATION FAIRLYSECURE)same ass existin all suburbanUS adultsEXTVALINFER#1INTVALIDITYINFEREXTVAL INF#2Accessiblepopulation

Same assocexist in allFraminghamadults(GENERALIZATION LESSSECURE)exists in:a) people livingother contriesb) other USadults

The three steps in designing the protocol for choosing the study subjects

STEP #1Target populations

Specify clinical and demo-graphic characteristicss

CRITERIA

Well suited to theresearch questionSTUDYPLAN(Truth in th study)RESEARCHQUESTION(Truth in the Universe)

STEP #2Target Accessiblepopulations

Specify temporal and demo-graphic characteristicss

CRITERIA

Rep of target populations andeasy to thestudySTEP #3Intended sample

Design an approachto selecting the sample

CRITERIA

Rep of accessiblepopulations andeasy to doSamplingSpecification

SAMPLINGSimple random samplingSystematic samplingStratified random samplingCluster sampling

Consecutive sampling- a study of upper respiratory illness in patients seen during a 2 -month period beginning in AugustConvenience sampling- The Multiple Risk Factor Intervention TrialJudgmental sampling- a study of the effectiveness of a brochure about fat-controlled diets.Probability samplingNonprobability sampling