SlideShare a Scribd company logo
SOC 340 LECTURE: WK 2
Representativeness & Randomness*
*Source:
Creswell, J. W. (2003). Research design: Qualitative, quantitative & mixed method. Thousand Oaks, CA: Sage
Babbie, E. (2014). The basics of social research. Belmont, CA: Sage Publishing 1
PROBABILTY THEORY OF SAMPLING
WHAT IS PROBABILITY?
PROBABILITY IS THE MEASURE OF THE LIKELIHOOD THAT AN EVENT WILL OCCUR. PROBABILITY IS
QUANTIFIED AS A NUMBER BETWEEN 0 AND 1, WHERE, LOOSELY SPEAKING, 0 INDICATES IMPOSSIBILITY
AND 1 INDICATES CERTAINTY. THE HIGHER THE PROBABILITY OF AN EVENT, THE MORE LIKELY IT IS THAT THE
EVENT WILL OCCUR. A SIMPLE EXAMPLE IS THE TOSSING OF A FAIR (UNBIASED) COIN.
WHAT IS PROBABILITY SAMPLING?
PROBABILITY SAMPLING DESCRIBES THE PROCESS OF SELECTING SAMPLES IN ACCORDANCE WITH
PROBABILITY THEORY WHICH TYPICALLY INCLUDE A RANDOM PROCESS FOR SELECTION. TYPES OF
PROBABILITY SAMPLING THAT WE WILL BE CONCERNED WITH ARE:
SIMPLE RANDOM SAMPLING
SYSTEMATIC RANDOM SAMPLING
WHAT IS NON-PROBABILITY SAMPLING?
ANY SAMPLING SELECTION PROCESS THAT DOES NOT CONFORM TO PROBABILITY THEORY. TYPES OF
NONPROBABILITY SAMPLING THAT WE WILL BE CONCERNED WITH ARE:
PURPOSIVE SAMPLING
SNOWBALL SAMPLING
AVAILABLE RESPONDENTS SAMPLING
QUOTA SAMPLING
2
SAMPLING BIAS
REPRESENTATIVENESS
PURPOSE OF THE SAMPLING PROCESS:
TO PROVIDE INFORMATION ABOUT A TOTAL POPULATION BY SELECTING A SAMPLE OF THAT POPULATION THAT
CONTAINS THE SAME VARIATIONS AS THE TOTAL POPULATION. IN OTHER WORDS, THE SAMPLE MUST BE
REPRESENTATIVE OF THE POPULATION. FOR INSTANCE, IF THE TOTAL PUPULATION IS SPLIT 50/50 BETWEEN
GENDER TYPES, THE SAMPLE SHOULD ALSO BE SPLIT IN CLOSE TO THE SAME WAY, IF NOT EXACTLY.
BIAS:
RESULTS FROM INADEQUATE PREPARATION OF THE SAMPLE SELECTION, WHICH LEADES TO A LACK OF
REPRESENTATIVENESS.
REPRESENTATIVENESS:
THE QUALITY OF THE SAMPLE HAVING THE SAME DISTRIBUTION OF CHARACTERISTICS AS THE TOTAL
POPULATION. REPRESENTATIVENESS IS IMPROVED BY PROBABILITY SAMPLING & CAN BE THE BASIS FOR
GENERALIZING THE RESULTS OF THE RESEARCH STUDY.
EQUAL PROBABILITY OF SELECTION:
A METHOD THAT ENSURES EACH MEMBER OF THE TOTAL POPULATION HAS THE SAME CHANCE OF BEING
SELECTED AS A MEMBER OF THE SAMPLE GROUP
3
PROBABILITY THEORY
PROBABILITY THEORY:
A MATHEMATICAL PROCESS THAT ENSURES RESEARCHERS WILL SELECT SAMPLE POPULATIONS THAT
ARE REPRESENTATIVE OF THE TOTAL POPULATION FROM WHICH THE SAMPLE IS DERIVED. IT ALSO
ENABLES RESEARCHERS TO STATISTICALLY ANALYZE THE RESULTS OF THE RESEARCH STUDY & TO
APPLY THOSE RESULTS TO THE TOTAL POPULATION (I.E., GENERALIZE THE RESULTS.
RANDOM SELECTION:
IS THE PROCESS BY WHICH EACH ELEMENT (MEMBER OF THE TOTAL POPULATION) HAS AN EQUAL
CHANCE OF BEING SELECTED INTO THE SAMPLE POPULATION. FOR EXAMPLE: FLIPPING A COIN 100
TIMES. SINCE THERE ARE ONLY TWO POSSIBILITIES, HEADS OR TAILS, THERE IS AN EQUAL CHANCE
THAT ONE OR THE OTHER WILL BE THE RSULT OF A FLIP.
REASONS FOR USING RANDOM SLECTION:
1. IT REDUCES THE CHANCE OF UNCONSCIOUS BIAS
2. IT CONFORMS TO PROBABILITY THEORY & IMPROVES THE ACCURACY OF THE SAMPLE
4
KEY TERMS
ELEMENT:
THE UNIT OF WHICH THE POPULATION (E.G.; WILMU STUDENTS) IS COMPRISED & WHICH IS
SELECTED FOR THE SAMPLE
TOTAL POPULATION (ALSO CALLED THE STUDY POPULATION):
THE AGGREGATION OF ALL THE ELEMENTS BEING STUDIED (E.G.; WILMU STUDENTS)
SAMPLE POPULATION:
A SUB POPULATION OF THE TOTAL POPULATION RANDOMLY SELECTED THAT IS REPRESENTATIVE OF THE
TOTAL POPULATION
SAMPLING UNIT:
THE ELEMENT OF SET OF ELEMENTS SELECTED IN SOME STAGE OF SAMPLING
PARAMETER:
THE SUMMARY DESCRIPTION OF A GIVEN VARIABLE IN A POPULATION
5

More Related Content

Similar to Soc 331 lecture probability theory

43911.ppt
43911.ppt43911.ppt
Sample methods
Sample methodsSample methods
Sample methods
Nasiru Ibrahim Barda
 
Stat ppt
Stat pptStat ppt
Stat ppt
suganyababu14
 
Tqm sampling
Tqm   samplingTqm   sampling
Tqm sampling
Durai Manikkam
 
Ppt sampling
Ppt  samplingPpt  sampling
Ppt sampling
Irene Mutuku
 
43911
4391143911
Tqm sampling 3
Tqm   sampling 3Tqm   sampling 3
Tqm sampling 3
Durai Manikkam
 
Sampling Methods
Sampling MethodsSampling Methods
Sampling Methods
Abdulazim N.Elaati
 
Tqm sampling
Tqm   samplingTqm   sampling
Tqm sampling
Durai Manikkam
 
Research Method
Research MethodResearch Method
Research Method
DrMaralusiddaiahHM
 
Sampling method in research
Sampling method in researchSampling method in research
Sampling method in research
Muhammad Musawar Ali
 
Sample method
Sample methodSample method
Sample method
Shilpi Panchal
 
Mixed Methods research
Mixed Methods researchMixed Methods research
Mixed Methods research
Dr Arindam Basu
 
GRP8-Population and Sampling-COELHO.pdf
GRP8-Population and Sampling-COELHO.pdfGRP8-Population and Sampling-COELHO.pdf
GRP8-Population and Sampling-COELHO.pdf
MaLourdesLazaro1
 
Sampling
SamplingSampling
Many decisions are based on beliefs concerning the likelihoo.docx
Many decisions are based on beliefs concerning the likelihoo.docxMany decisions are based on beliefs concerning the likelihoo.docx
Many decisions are based on beliefs concerning the likelihoo.docx
alfredacavx97
 
Discourse analysis ca summary
Discourse analysis  ca summaryDiscourse analysis  ca summary
Discourse analysis ca summaryEdgar Lucero
 
Lecture on research MSW research.pptx
Lecture on research MSW research.pptxLecture on research MSW research.pptx
Lecture on research MSW research.pptx
Victor Eyo Assi
 

Similar to Soc 331 lecture probability theory (20)

43911.ppt
43911.ppt43911.ppt
43911.ppt
 
Sample methods
Sample methodsSample methods
Sample methods
 
Stat ppt
Stat pptStat ppt
Stat ppt
 
Tqm sampling
Tqm   samplingTqm   sampling
Tqm sampling
 
Ppt sampling
Ppt  samplingPpt  sampling
Ppt sampling
 
43911
4391143911
43911
 
43911
4391143911
43911
 
Tqm sampling 3
Tqm   sampling 3Tqm   sampling 3
Tqm sampling 3
 
43911
4391143911
43911
 
Sampling Methods
Sampling MethodsSampling Methods
Sampling Methods
 
Tqm sampling
Tqm   samplingTqm   sampling
Tqm sampling
 
Research Method
Research MethodResearch Method
Research Method
 
Sampling method in research
Sampling method in researchSampling method in research
Sampling method in research
 
Sample method
Sample methodSample method
Sample method
 
Mixed Methods research
Mixed Methods researchMixed Methods research
Mixed Methods research
 
GRP8-Population and Sampling-COELHO.pdf
GRP8-Population and Sampling-COELHO.pdfGRP8-Population and Sampling-COELHO.pdf
GRP8-Population and Sampling-COELHO.pdf
 
Sampling
SamplingSampling
Sampling
 
Many decisions are based on beliefs concerning the likelihoo.docx
Many decisions are based on beliefs concerning the likelihoo.docxMany decisions are based on beliefs concerning the likelihoo.docx
Many decisions are based on beliefs concerning the likelihoo.docx
 
Discourse analysis ca summary
Discourse analysis  ca summaryDiscourse analysis  ca summary
Discourse analysis ca summary
 
Lecture on research MSW research.pptx
Lecture on research MSW research.pptxLecture on research MSW research.pptx
Lecture on research MSW research.pptx
 

Recently uploaded

Home assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdfHome assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdf
Tamralipta Mahavidyalaya
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
Pavel ( NSTU)
 
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...
Levi Shapiro
 
Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.
Ashokrao Mane college of Pharmacy Peth-Vadgaon
 
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXXPhrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
MIRIAMSALINAS13
 
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
siemaillard
 
"Protectable subject matters, Protection in biotechnology, Protection of othe...
"Protectable subject matters, Protection in biotechnology, Protection of othe..."Protectable subject matters, Protection in biotechnology, Protection of othe...
"Protectable subject matters, Protection in biotechnology, Protection of othe...
SACHIN R KONDAGURI
 
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
Nguyen Thanh Tu Collection
 
Model Attribute Check Company Auto Property
Model Attribute  Check Company Auto PropertyModel Attribute  Check Company Auto Property
Model Attribute Check Company Auto Property
Celine George
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
Sandy Millin
 
Honest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptxHonest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptx
timhan337
 
A Strategic Approach: GenAI in Education
A Strategic Approach: GenAI in EducationA Strategic Approach: GenAI in Education
A Strategic Approach: GenAI in Education
Peter Windle
 
How libraries can support authors with open access requirements for UKRI fund...
How libraries can support authors with open access requirements for UKRI fund...How libraries can support authors with open access requirements for UKRI fund...
How libraries can support authors with open access requirements for UKRI fund...
Jisc
 
Acetabularia Information For Class 9 .docx
Acetabularia Information For Class 9  .docxAcetabularia Information For Class 9  .docx
Acetabularia Information For Class 9 .docx
vaibhavrinwa19
 
How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17
Celine George
 
Language Across the Curriculm LAC B.Ed.
Language Across the  Curriculm LAC B.Ed.Language Across the  Curriculm LAC B.Ed.
Language Across the Curriculm LAC B.Ed.
Atul Kumar Singh
 
Instructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptxInstructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptx
Jheel Barad
 
Polish students' mobility in the Czech Republic
Polish students' mobility in the Czech RepublicPolish students' mobility in the Czech Republic
Polish students' mobility in the Czech Republic
Anna Sz.
 
Lapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdfLapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdf
Jean Carlos Nunes Paixão
 
CLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCE
CLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCECLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCE
CLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCE
BhavyaRajput3
 

Recently uploaded (20)

Home assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdfHome assignment II on Spectroscopy 2024 Answers.pdf
Home assignment II on Spectroscopy 2024 Answers.pdf
 
Synthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptxSynthetic Fiber Construction in lab .pptx
Synthetic Fiber Construction in lab .pptx
 
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...
 
Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.Biological Screening of Herbal Drugs in detailed.
Biological Screening of Herbal Drugs in detailed.
 
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXXPhrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
Phrasal Verbs.XXXXXXXXXXXXXXXXXXXXXXXXXX
 
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 
"Protectable subject matters, Protection in biotechnology, Protection of othe...
"Protectable subject matters, Protection in biotechnology, Protection of othe..."Protectable subject matters, Protection in biotechnology, Protection of othe...
"Protectable subject matters, Protection in biotechnology, Protection of othe...
 
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
BÀI TẬP BỔ TRỢ TIẾNG ANH GLOBAL SUCCESS LỚP 3 - CẢ NĂM (CÓ FILE NGHE VÀ ĐÁP Á...
 
Model Attribute Check Company Auto Property
Model Attribute  Check Company Auto PropertyModel Attribute  Check Company Auto Property
Model Attribute Check Company Auto Property
 
2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...2024.06.01 Introducing a competency framework for languag learning materials ...
2024.06.01 Introducing a competency framework for languag learning materials ...
 
Honest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptxHonest Reviews of Tim Han LMA Course Program.pptx
Honest Reviews of Tim Han LMA Course Program.pptx
 
A Strategic Approach: GenAI in Education
A Strategic Approach: GenAI in EducationA Strategic Approach: GenAI in Education
A Strategic Approach: GenAI in Education
 
How libraries can support authors with open access requirements for UKRI fund...
How libraries can support authors with open access requirements for UKRI fund...How libraries can support authors with open access requirements for UKRI fund...
How libraries can support authors with open access requirements for UKRI fund...
 
Acetabularia Information For Class 9 .docx
Acetabularia Information For Class 9  .docxAcetabularia Information For Class 9  .docx
Acetabularia Information For Class 9 .docx
 
How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17How to Make a Field invisible in Odoo 17
How to Make a Field invisible in Odoo 17
 
Language Across the Curriculm LAC B.Ed.
Language Across the  Curriculm LAC B.Ed.Language Across the  Curriculm LAC B.Ed.
Language Across the Curriculm LAC B.Ed.
 
Instructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptxInstructions for Submissions thorugh G- Classroom.pptx
Instructions for Submissions thorugh G- Classroom.pptx
 
Polish students' mobility in the Czech Republic
Polish students' mobility in the Czech RepublicPolish students' mobility in the Czech Republic
Polish students' mobility in the Czech Republic
 
Lapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdfLapbook sobre os Regimes Totalitários.pdf
Lapbook sobre os Regimes Totalitários.pdf
 
CLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCE
CLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCECLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCE
CLASS 11 CBSE B.St Project AIDS TO TRADE - INSURANCE
 

Soc 331 lecture probability theory

  • 1. SOC 340 LECTURE: WK 2 Representativeness & Randomness* *Source: Creswell, J. W. (2003). Research design: Qualitative, quantitative & mixed method. Thousand Oaks, CA: Sage Babbie, E. (2014). The basics of social research. Belmont, CA: Sage Publishing 1
  • 2. PROBABILTY THEORY OF SAMPLING WHAT IS PROBABILITY? PROBABILITY IS THE MEASURE OF THE LIKELIHOOD THAT AN EVENT WILL OCCUR. PROBABILITY IS QUANTIFIED AS A NUMBER BETWEEN 0 AND 1, WHERE, LOOSELY SPEAKING, 0 INDICATES IMPOSSIBILITY AND 1 INDICATES CERTAINTY. THE HIGHER THE PROBABILITY OF AN EVENT, THE MORE LIKELY IT IS THAT THE EVENT WILL OCCUR. A SIMPLE EXAMPLE IS THE TOSSING OF A FAIR (UNBIASED) COIN. WHAT IS PROBABILITY SAMPLING? PROBABILITY SAMPLING DESCRIBES THE PROCESS OF SELECTING SAMPLES IN ACCORDANCE WITH PROBABILITY THEORY WHICH TYPICALLY INCLUDE A RANDOM PROCESS FOR SELECTION. TYPES OF PROBABILITY SAMPLING THAT WE WILL BE CONCERNED WITH ARE: SIMPLE RANDOM SAMPLING SYSTEMATIC RANDOM SAMPLING WHAT IS NON-PROBABILITY SAMPLING? ANY SAMPLING SELECTION PROCESS THAT DOES NOT CONFORM TO PROBABILITY THEORY. TYPES OF NONPROBABILITY SAMPLING THAT WE WILL BE CONCERNED WITH ARE: PURPOSIVE SAMPLING SNOWBALL SAMPLING AVAILABLE RESPONDENTS SAMPLING QUOTA SAMPLING 2
  • 3. SAMPLING BIAS REPRESENTATIVENESS PURPOSE OF THE SAMPLING PROCESS: TO PROVIDE INFORMATION ABOUT A TOTAL POPULATION BY SELECTING A SAMPLE OF THAT POPULATION THAT CONTAINS THE SAME VARIATIONS AS THE TOTAL POPULATION. IN OTHER WORDS, THE SAMPLE MUST BE REPRESENTATIVE OF THE POPULATION. FOR INSTANCE, IF THE TOTAL PUPULATION IS SPLIT 50/50 BETWEEN GENDER TYPES, THE SAMPLE SHOULD ALSO BE SPLIT IN CLOSE TO THE SAME WAY, IF NOT EXACTLY. BIAS: RESULTS FROM INADEQUATE PREPARATION OF THE SAMPLE SELECTION, WHICH LEADES TO A LACK OF REPRESENTATIVENESS. REPRESENTATIVENESS: THE QUALITY OF THE SAMPLE HAVING THE SAME DISTRIBUTION OF CHARACTERISTICS AS THE TOTAL POPULATION. REPRESENTATIVENESS IS IMPROVED BY PROBABILITY SAMPLING & CAN BE THE BASIS FOR GENERALIZING THE RESULTS OF THE RESEARCH STUDY. EQUAL PROBABILITY OF SELECTION: A METHOD THAT ENSURES EACH MEMBER OF THE TOTAL POPULATION HAS THE SAME CHANCE OF BEING SELECTED AS A MEMBER OF THE SAMPLE GROUP 3
  • 4. PROBABILITY THEORY PROBABILITY THEORY: A MATHEMATICAL PROCESS THAT ENSURES RESEARCHERS WILL SELECT SAMPLE POPULATIONS THAT ARE REPRESENTATIVE OF THE TOTAL POPULATION FROM WHICH THE SAMPLE IS DERIVED. IT ALSO ENABLES RESEARCHERS TO STATISTICALLY ANALYZE THE RESULTS OF THE RESEARCH STUDY & TO APPLY THOSE RESULTS TO THE TOTAL POPULATION (I.E., GENERALIZE THE RESULTS. RANDOM SELECTION: IS THE PROCESS BY WHICH EACH ELEMENT (MEMBER OF THE TOTAL POPULATION) HAS AN EQUAL CHANCE OF BEING SELECTED INTO THE SAMPLE POPULATION. FOR EXAMPLE: FLIPPING A COIN 100 TIMES. SINCE THERE ARE ONLY TWO POSSIBILITIES, HEADS OR TAILS, THERE IS AN EQUAL CHANCE THAT ONE OR THE OTHER WILL BE THE RSULT OF A FLIP. REASONS FOR USING RANDOM SLECTION: 1. IT REDUCES THE CHANCE OF UNCONSCIOUS BIAS 2. IT CONFORMS TO PROBABILITY THEORY & IMPROVES THE ACCURACY OF THE SAMPLE 4
  • 5. KEY TERMS ELEMENT: THE UNIT OF WHICH THE POPULATION (E.G.; WILMU STUDENTS) IS COMPRISED & WHICH IS SELECTED FOR THE SAMPLE TOTAL POPULATION (ALSO CALLED THE STUDY POPULATION): THE AGGREGATION OF ALL THE ELEMENTS BEING STUDIED (E.G.; WILMU STUDENTS) SAMPLE POPULATION: A SUB POPULATION OF THE TOTAL POPULATION RANDOMLY SELECTED THAT IS REPRESENTATIVE OF THE TOTAL POPULATION SAMPLING UNIT: THE ELEMENT OF SET OF ELEMENTS SELECTED IN SOME STAGE OF SAMPLING PARAMETER: THE SUMMARY DESCRIPTION OF A GIVEN VARIABLE IN A POPULATION 5