dr. supakit nootyaskool it kmitl
TRANSCRIPT
Research Methodology and StatisticChapter 4: Conceptual research
design Dr. Supakit Nootyaskool
Objective
• To give idea planning research design.• To explain kinds of selecting a study design.
Topics
4.1 Research design4.2 Selecting a study design
4.1 Research designMeaning
Kerlinger, 1986: 276
“Research design is a plan structure andstrategy of investigations enable one toobtain answers to research questions”
Selltiz, 1962 “Research design is the arrangement ofconditions for collection and analysis ofdata in the manner that aims tocombine relevance of research purposewith economy in process”
4.1 Research designMeaning
Cooper and Schindler, 2003
“Summarizes the essential of researchdesign as an activity and time basedplan; always based on the researchquestion; guide the selection of sourcesand types of information; a frameworkfor specifying the relationship amongthe study variables and outlines theprocedures for every research activity. ”
4.1 Research designMeaning
Thyer, 1993: 94
“A traditional research design is ablueprint or detailed plan for how aresearch study is to be completed—operationalizing variables so they canbe measured selecting a sample ofinterest to study, collecting data to beused as a basis for testing hypothesis,and analyzing the results ”
4.2 Selecting a study designType of study
design
Number of contacts
one
cross‐sectional study
two
before and after study
three
longitudinal study
Reference period
Retrospective
Prospective
Retrospective‐prospective
Nature of the investigation
experimental
non‐experimental
semi‐experimental
4.2.1 Cross‐sectional study
Babbie 1989:89 “Designed to study some phenomenon by taking a cross section of it on time” The study from a cross section is easily design by doing:
1. Define study population, after that sample population in a group to study.
2. Collect with questionnaire and check studying result3. One contact collecting data
Cross section (n) กลุ่มตวัอย่าง, การตดัขวาง On time (idm) ทนักําหนด
4.2.1 Cross‐sectional study: questionnaire
4.2.1 Cross‐sectional study: result
4.2.2 Before and after design study
The study does two period of times.
Difference = AfterResult – BeforeResult
A situation
BeforeStudy Before After
Study After
4.2.2 Before and after design study: Example1
T25 after 8weeks
4.2.2 Before and after design study: Example2
4.2.2 Before and after design study: regression effect (ผลกระทบการถดถอย)
A situation
BeforeStudy Before After
Study After
4.2.3 Longitudinal study
4.2.3 Longitudinal study
• Longitudinal study– More than one time collecting data
• Regression effect
4.2.3 Longitudinal study: regression effect (ผลกระทบการถดถอย)
A situation
Study1 Study2 Study3
4.2.4 Retrospective study
Retrospective is analysis on the past of the situation from having information. Dividing into three groups:
1. retrospective study (past)2. Prospective study (future)3. Retrospective‐prospective study (past<‐>future)
Retrospective (adj) ระลึกถึงความหลงั มองยอ้นอดีต Prospective (adj) ทีค่าดหวงัไว้
Prospective S.Retrospective S.At present
4.2.4.1 Retrospective study
2011 Thailand flood 1979 Energy Crisis
4.2.4.2 Prospective study
4.2.4.2 Retrospective ‐ Prospectivestudy
• Joking
4.2.5 Nature of Investigation in research study
• The research that find out the truth has three kinds.– Experimental study– Non‐experimental study– Semi‐experimental study
4.2.5 Nature of Investigation in research study
• The research that find out the truth has three kinds.– Experimental study– Non‐experimental study– Semi‐experimental study
Consist of:• The after‐only design
The before‐and‐after designThe double‐control designThe comparative designThe placebo designBlind studyDouble‐blind study
4.2.5.1 Experimental study: After‐only design
4.2.5.2 Experimental study: Before and after design
ChangeVar = AfterVar – BeforeVar
NN
H = N = 20H = 10N = 20
DataSize 100
Recog
90%
Recog.
90%
Before—Normalize data setTraining time = 1.5sec% Recognition = 90%
After—Normalize data setTraining time = 1.5sec% Recognition = 95.5%
4.2.5.3 Experimental study: Double control design
Control1
AfterBefore
Control1
Control2 Control2
4.2.5.4 Experimental study: Placebo design
ยา/แป้ง
แป้ง
ยา
Placebo (n) ยาทีไ่ม่มีฤทธิ์
4.2.5.5 Experimental study: single‐blind study
an experiment in which the person collecting data knows whether the subject is in the control group or the experimental group, but subjects do not known.
4.2.5.1 Experimental study: Double‐blind study
double‐blind study ‐ an experimental procedure in which neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment; "a double‐blind procedure is used to guard against both experimenter bias and placebo effects"
Reference
• http://www.youtube.com/watch?v=HYuxE3YetQo