Nonexperimental research design


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Nonexperimental research design

  1. 1. MR. JAYESH
  2. 2. INTRODUCTION… Nonexperimental research design is one of thebroad categories of research designs, in which theresearcher observes the phenomena as they occurnaturally, & no external variables are introduced. It is a research design in which variables are notdeliberately manipulated, nor is the settingcontrolled. In nonexperimental research, researchers collectdata without making changes or
  3. 3. NEED OF NONEXPERIMENTAL DESIGN Nonexperimental designs can be used to conduct a studyare as follows: The studies in which the independent variables cannot bemaintained. The studies in which it is unethical to manipulate theindependent variable, i.e. manipulation may causephysical or psychological harm to subjects. The studies or research situations where it is notpractically possible to conduct experiments. Descriptive-type studies that do not require anyexperimental
  4. 4. TYPES OF NONEXPERIMENTAL RESEARCHDESIGNDescriptive DesignUnivariant descriptive designExploratory descriptive designComparative descriptive designCorrelational designProspective designRetrospective designDevelopmental Research DesignCross-sectional designLongitudinal designSurvey Research
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  6. 6. INTRODUCTION… The purpose of descriptive studies is toobserve, describe, & document aspects of asituation as it naturally occurs, & sometimesto serve as a starting point for hypothesisgeneration or theory
  7. 7. MAIN FEATURES… Descriptive designs are used to observe, document, &describe a phenomenon occurring in its naturalsetting without any manipulation or control. The descriptive studies are designed to gain moreinformation about characteristics within a particularfield in the real world. Descriptive studies provide an impression of asituation as it occurs in natural settings. Descriptive studies do not involve the manipulationof variables, & variables are studies as they exist in thereal
  8. 8. Count… Descriptive design may be used to develop theories,identify problems with current practices, justifycurrent practices, make judgments, or determineother practices in similar situations. In descriptive studies, bias is prevented throughoperational definitions of variables, large sample size,random sampling techniques, valid & reliableresearch tools, & formal data collection methods. Descriptive designs include identification ofphenomenon of interest, identifying the variableswithin the phenomenon, developing operationaldefinitions of the variables, & describing thevariables.
  9. 9. TYPES OF DESCRIPTIVE DESIGN1. Univariant descriptive design2. Exploratory design3. Comparative
  10. 10. 1. Univariant descriptive design Univariant descriptive designs are undertaken to describethe frequency of occurrence of a phenomenon. This design does not necessarily focus on the study of asingle variable; there may be one or more variablesinvolved in the study. For example, a researcher is interested in assessing theexperiences of patients suffering from rheumatoidarthritis. In this study, the researcher may describe thefrequency of different symptoms experienced by thepatients & the type of treatment they received during thecourse of disease, etc. There are multiple variables in thisresearch
  11. 11. 2. Exploratory design: Exploratory design is used to identify, explore, &describe the existing phenomenon & its relatedfactors. In other words, it is not only a simple description orthe frequency of occurrence of a phenomenon, butits in-depth exploration & a study of its relatedfactors to improve further understanding about aless-understood phenomenon. For example, an exploratory study to assess themultifactorial dimensions of falls & home safetymeasures for elderly people living in selectedcommunities in the city
  12. 12. 3. Comparative design: Comparative design involves comparing &contrasting two or more samples of study subjects onone or more variables, often at a single point of time. This design is used to compare two distinct groups onthe basis of selected attributed such as knowledgelevel, perceptions, & attitudes; physical orpsychological symptoms; & so on. For example, ‘A comparative study on healthproblems among rural & urban older people indistrict Mehsana,
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  14. 14. INTRODUCTION… This is a nonexperimental design, where researcherexamines the relationship between two or morevariables in a natural setting without manipulation orcontrol. In other words, it is a research design whereresearchers study the relationship of two or morevariables without any intervention. For example, this design was used for ‘A correlationalstudy on the effect of smoking on lung cancer amongpeople in
  15. 15. MAIN FEATURES… In correlational studies, the researchersexamine the strength of relationshipsbetween variables by determining howchange in one variable is correlated withchange in the other variable. Generally, correlational studies haveindependent & dependent variables, but theeffect of independent variable is observedon dependant variable withoutmanipulating the independent
  16. 16. Count… In some correlational studies, identification of theindependent & dependent variables is difficult; however, inmost correlational studies, the independent variable isidentified, which, without any intervention, influences thedependent variable. For example, this design was used in ‘acorrelational investigation of the study habits & visual acuityamong school children studying in selected schools in thecity of Mehsana’. In this study, study habits are theindependent variable, while visual acuity is the dependentvariable. In epidemiological language these studies are known as cause& effect study, where cause & effect relationship is investigatein natural settings without imposing experimentalinterventions. This cause & effect relationship can beinvestigated either in forward manner, i.e. from cause toeffect (prospective) or backward manner, i.e. effect to cause(retrospective)
  17. 17. TYPES OF CORRELATIONALRESEARCH DESIGN1. Prospective research design2. Retrospective research
  18. 18. 1. Prospective research design: A design in which the researcher relates thepresent to the future is a prospective researchdesign . Prospective studies start with a presumed cause &then go to presumed effects. In this research design , researcher observesphenomenon from cause to effect. Prospective designs are often longitudinal, butmay also be cross
  19. 19. Count… for example, a researcher conducting ‘a prospectivecorrelational study on effect of maternal infectionduring pregnancy on foetal development &pregnancy outcome .’ In this study, the researcher starts by collecting datafrom pregnant women regarding any history ofinfection among women during their currentpregnancies, next observes foetal development &pregnancy outcome, & finally analyses therelationship of maternal infection during pregnancy& foetal development & pregnancy
  20. 20. 2. Retrospective research design: A design in which the researcher studies thecurrent phenomenon by seeking informationfrom past is a retrospective research design. In this the researcher links the presentphenomenon with the past events. In other words, the researcher has a backwardapproach to study a phenomenon, where he orshe moves from effect to identify the
  21. 21. Count… For example, this design was used in ‘aretrospective correlational study on substance-abuse-related high-risk factors amongtraumatic head injury patients admitted inneurosurgery ICU of Geetanjali MedicalCollege & Hospital, Udaipur’. In this study, the researcher first approachedhead injury patients, & then tried to identifythe number of head injuries that occurredunder the influence of substance
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  23. 23. INTRODUCTION… Developmental research design examines thephenomenon with reference to time. Developmental research designs are generally used asadjunct research designs with other research designssuch as cross-sectional-descriptive, longitudinal-correlational research
  24. 24. TYPES OF DEVELOPMENTALRESEARCH DESIGN1. Cross-sectional design2. Longitudinal
  25. 25. 1. Cross-sectional design: Cross-sectional research design is one in whichresearcher collects data at particular point of time(one period of data collection). These studies are easier & more convenient to carryout. For example, a researcher is interested in assessingthe awareness on swine flu among people of an area. Here the researcher interacts only once to collectawareness-related data from
  26. 26. 2. Longitudinal design: Longitudinal research design is used to collect data over anextended time period (long-time study). Its value is in its ability to demonstrate change over a periodof time. For example, a researcher in interested in the perception ofnursing students towards nursing profession from thebeginning of nursing programme to its end. In this example, it is appropriate to use the longitudinalresearch design to study this phenomenon. Longitudinal studies are generally classified into three types:I. Trend studiesII. Panel studiesIII. Follow-up
  27. 27. Count…I. Trend studies: These help to investigate a sample from ageneral population over a time withrespect to some phenomenon. Trend studies permit researchers toexamine pattern & rate of changes & tomake prediction about future directionbased on previously identified patterns &rates of
  28. 28. Count…II. Panel studies: A panel in research is referred to the sample ofpeople involved in a study. In panel studies, same people are involved & over aperiod of time they become more informative onthe phenomenon than the subjects in trends studiesbecause the researcher can not only examine thepatterns of change, & but also the reasons forchange. The same selected people are contacted for two ormore times to collect further
  29. 29. Count…III.Follow-up studies: These are undertaken to determine thesubsequent states of subject(s) with aspecific condition or those who havereceived a specific
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  31. 31. CONCEPT… Epidemiology is the study to investigate thedistribution & causes of the diseases inpopulation. Therefore, epidemiological studies are generallyconducted to investigate causes of differentdiseases in either prospective approaches(causes to effect) or retrospective designs. Prospective studies are known as cohort studies& retrospective studies are called
  32. 32. Count…Cohort studies:• In this design, a longitudinal approach is used toinvestigate the occurrence of a disease in existingpresumed causes.• For example, a researcher longitudinally observes thesmokers for development of lung cancer.Case-control studies:• In this design, causes of a disease are investigated afterthe occurrence of a disease.• For example, a researcher investigates the history ofsmoking in patients diagnosed with lung
  33. 33. ADVANTAGE OF NONEXPERIMENTALRESEARCH DESIGN Nonexperimental research designs tend to be closest toreal-life situation. Nonexperimental research designs are most suitable forthe nursing research studies.. Numerous human characteristics are inherently notsubject to experimental manipulation (e.g. blood type,personality, health beliefs, medical diagnosis, etc.) There are many variable that could technically bemanipulated, but manipulated is forbidden on
  34. 34. DISADVANTAGES OF NONEXPERIMENTALRESEARCH DESIGN The major disadvantage of nonexperimental researches isthat the results obtained & the relationship between thedependent & independent variable can never beabsolutely clear & error-free. Nonexperimental studies are conducted for comparativepurposes using nonrandomly selected groups, which maynot be homogeneous & tend to be dissimilar in differenttraits or characteristics, which may affect the authenticity& generalizability of the study
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