Presentation on theme: "Chapter 3 Introduction to Quantitative Research"— Presentation transcript:
1Chapter 3 Introduction to Quantitative Research Based on the deductive modelQuantity is the unit of analysisAmountsFrequenciesDegreesValuesIntensityUses statistics for greater precision and objectivityCopyright c 2001 The McGraw Hill Companies, Inc.
2Model for Conceptualizing Quantitative Research Overall purpose or objectiveResearch literatureResearch questions and hypothesesSelecting appropriate methodsValidity and reliability of the dataCopyright c 2001 The McGraw Hill Companies, Inc.
3Creating the Foundation for Quantitative Research ConceptAbstract thinking to distinguish it from other elementsConstructTheoretical definition of a concept; must be observable or measurableVariablePresented in research questions and hypothesesOperationalizationSpecifically how the variable is observed or measuredCopyright c 2001 The McGraw Hill Companies, Inc.
4Research Hypotheses for Quantitative Research Educated guess or presumption based on literatureStates the nature of the relationship between two or more variablesPredicts the research outcomeResearch study designed to test the relationship described in the hypothesisCopyright c 2001 The McGraw Hill Companies, Inc.
5Quantitative Research Hypotheses Directional hypothesisPrecise statement indicating the nature and direction of the relationship/difference between variablesNondirectional hypothesisStates only that relationship/difference will occurCopyright c 2001 The McGraw Hill Companies, Inc.
6Copyright c 2001 The McGraw Hill Companies, Inc. Assessing HypothesesSimply stated?Single sentence?At least two variables?Variables clearly stated?Is the relationship/difference precisely stated?Testable?Copyright c 2001 The McGraw Hill Companies, Inc.
7Copyright c 2001 The McGraw Hill Companies, Inc. Null HypothesesImplicit complementary statement to the research hypothesisStates no relationship/difference exists between variablesStatistical test performed on the nullAssumed to be true until support for the research hypothesis is demonstratedCopyright c 2001 The McGraw Hill Companies, Inc.
8Research Traditions in the Use of Hypotheses Hypotheses are always tentativeResearch hypothesis, not the null hypothesis, is the focus of the research and presented in the research reportCopyright c 2001 The McGraw Hill Companies, Inc.
9Research Questions in Quantitative Research Preferred when little is known about a communication phenomenonUsed when previous studies report conflicting resultsUsed to describe communication phenomenaCopyright c 2001 The McGraw Hill Companies, Inc.
10Copyright c 2001 The McGraw Hill Companies, Inc. Types of VariablesVariableElement that is identified in the hypothesis or research questionProperty or characteristic of people or things that varies in quality or magnitudeMust have two or more levelsMust be identified as independent or dependentCopyright c 2001 The McGraw Hill Companies, Inc.
11Independent Variables Manipulation or variation of this variable is the cause of change in other variablesTechnically, independent variable is the term reserved for experimental studiesAlso called antecedent variable, experimental variable, treatment variable, causal variable, predictor variableCopyright c 2001 The McGraw Hill Companies, Inc.
12Copyright c 2001 The McGraw Hill Companies, Inc. Dependent VariablesThe variable of primary interestResearch question/hypothesis describes, explains, or predicts changes in itThe variable that is influenced or changed by the independent variableIn non-experimental research, also called criterion variable, outcome variableCopyright c 2001 The McGraw Hill Companies, Inc.
13Relationship Between Independent and Dependent Variables Cannot specify independent variables without specifying dependent variablesNumber of independent and dependent variables depends on the nature and complexity of the studyThe number and type of variables dictates which statistical test will be usedCopyright c 2001 The McGraw Hill Companies, Inc.
14Intervening and Confounding Variables Intervening variablePresumed to explain or provide a link between independent and dependent variablesRelationship between the IV and DV can only be explained when the intervening variable is presentConfounding variableConfuses or obscures the effect of independent on dependentMakes it difficult to isolate the effects of the independent variableCopyright c 2001 The McGraw Hill Companies, Inc.
15Operationalizing Variables All variables need an operationalizationMultiple operationalizations exist for most variablesSpecifies the way in which variable is observed or measuredPractical and useful?Justified argument?Coincides with the conceptual definition?Copyright c 2001 The McGraw Hill Companies, Inc.
16Making the Case for Quantitative Research AdvantagesTradition and history implies rigorNumbers and statistics allows precise and exact comparisonsGeneralization of findingsLimitationsCannot capture complexity of communication over timeDifficult to apply outside of controlled environmentsCopyright c 2001 The McGraw Hill Companies, Inc.
17Issues of Reliability and Validity Reliability = consistency in procedures and in reactions of participantsValidity = truth - Does it measure what it intended to measure?When reliability and validity are achieved, data are free from systematic errorsCopyright c 2001 The McGraw Hill Companies, Inc.
18Threats to Reliability and Validity If measuring device cannot make fine distinctionsIf measuring device cannot capture people/things that differWhen attempting to measure something irrelevant or unknown to respondentCan measuring device really capture the phenomenon?Copyright c 2001 The McGraw Hill Companies, Inc.
19Other Sources of Variation Variation must represent true differencesOther sources of variationFactors not measuredPersonal factorsDifferences in situational factorsDifferences in research administrationNumber of items measuredUnclear measuring deviceMechanical or procedural issuesStatistical processing of dataCopyright c 2001 The McGraw Hill Companies, Inc.