Presentation on theme: "Conceptualization and Measurement"— Presentation transcript:
1Conceptualization and Measurement MEASUREMENT PROCESSBegins when the researcher formulates their research problem or hypothesis.Measurement process consists of moving from the abstract (concepts) to the concrete (measure of concepts).
2ConceptualizationConcepts are words or signs that refer to phenomena that share common characteristics.Concepts are building blocks of research.Conceptualization – process of clarifying what we mean by a concept. Involves providing a theoretical or conceptual definition of the concept.
3Specifying concepts facilitates measurement because it allows for more refined statements of problems and focuses your research.Given the hypothesis “education reduces prejudice.” Identify the concepts and define them.
4OperationalizationThis is the process of defining specific ways to infer the occurrence of specific phenomena.Involves providing operational definitions --consists of the specific questions asked, together with response categories to which cases are assigned.Many operational definitions are possible. Choose the one that fits your research question.
5When creating an operational definition, a researcher may consider many different empirical representations or indicators.Indicator -- single observable measure.
6Following are five statements which you may agree or disagree Following are five statements which you may agree or disagree. Using the 1-7 scale shown, indicate your agreement with each item by placing the appropriate number on the line preceding that item. Please be open and honest in responding7—Strongly agree6—Agree5--- Slightly agree4—Neither agree nor Disagree3—Slightly disagree2--- Disagree1--- Strongly disagree__ In most ways my life is close to ideal__ The Conditions of my life are excellent__ I am satisfied with my life__ So far I have gotten the important things I want in life__If I could live my life over, I would change almost nothing.
7Conceptualization and Measurement Continued Problems with Single Variables/ Indicators1) They often contain errors of classification2) They rarely capture all aspects of a conceptAlways best to measure complex concepts with multiple indicators.
8Following are five statements which you may agree or disagree Following are five statements which you may agree or disagree. Using the 1-7 scale shown, indicate your agreement with each item by placing the appropriate number on the line preceding that item. Please be open and honest in responding7—Strongly agree6—Agree5--- Slightly agree4—Neither agree nor Disagree3—Slightly disagree2--- Disagree1--- Strongly disagree__ In most ways my life is close to ideal__ The Conditions of my life are excellent__ I am satisfied with my life__ So far I have gotten the important things I want in life__If I could live my life over, I would change almost nothing
9Defining Variables and Attributes An attribute is a characteristic or quality of something.Variables are logical sets of attributesConceptualization and operationalization process can be seen as the specification of variables and the attributes composing them
10Every variable must have two important qualities: Attributes composing it must be exhaustiveAttributes composing a variable must be mutually exclusive.
11Levels of Measurements When we know a variable’s level of measurement we can better understand how cases vary on that variable and so understand more fully what we have measuredNOMINAL – also known as categorical or qualitative level variable – identifies variables whose values have no mathematical interpretation
12ORDINAL – rank orderable measure INTERVAL -- represent fixed measurement units but have no absolute zero.RATIO --These are variables that have a true zero point. That is a 0 that measures the absence of the phenomenon being measured.
13REMEMBER – do not measure things at the ordinal level when you can measure them at the ratio scale… measure things at the highest level of measurement possible.
14Validity and Reliability The extent to which measures indicate what they are intended to measure can be assessed with one or more of four basic approaches.
15Face ValidityFace validation – confidence you gain from careful inspection of a concept to see if it is appropriate “on its face”.Problem– does not provide convincing evidence of measurement of validity.
16Content ValidityEstablishes that the measure covers the full range of the concepts meaning. Researchers will have to do more literature review and identify the different aspects of the concept.
17Construct ValidityEstablished by showing that the measure is related to a variety of other measures as specified in a theory.Criterion ValidityEstablished when the scores obtained on one measure can be accurately compared to those obtained with a more direct or already validated measure of the same phenomenon.
18ReliabilityRefers to whether or not you get the same answer by using an instrument to measure something more than once.Tests for ReliabilityTest-retest – test people again and again.Parallel forms– investigator creates two equivalent forms of a scale of questions and administer each form to the same group. If the correlation between the scales is is high, then your measure is reliable.
19Split half method – administer half the scale to half the group and the other half of the scale to the other half of the group. If correlation is high, the measure is reliable.Internal consistency – assess that questions test the same concept. Eg. multiple choice test.