220 likes | 373 Views
Conceptualization and Measurement. MEASUREMENT PROCESS Begins when the researcher formulates their research problem or hypothesis . Measurement process consists of moving from the abstract (concepts) to the concrete (measure of concepts). Conceptualization.
E N D
Conceptualization and Measurement MEASUREMENT PROCESS • Begins when the researcher formulates their research problem or hypothesis. • Measurement process consists of moving from the abstract (concepts) to the concrete (measure of concepts).
Conceptualization • Concepts 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.
Specifying 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.
Operationalization • This 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.
When creating an operational definition, a researcher may consider many different empirical representations or indicators. • Indicator -- single observable measure.
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 responding 7—Strongly agree 6—Agree 5--- Slightly agree 4—Neither agree nor Disagree 3—Slightly disagree 2--- Disagree 1--- 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.
Conceptualization and Measurement Continued Problems with Single Variables/ Indicators 1) They often contain errors of classification 2) They rarely capture all aspects of a concept • Always best to measure complex concepts with multiple indicators.
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 responding 7—Strongly agree 6—Agree 5--- Slightly agree 4—Neither agree nor Disagree 3—Slightly disagree 2--- Disagree 1--- 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
Defining Variables and Attributes • An attribute is a characteristic or quality of something. • Variables are logical sets of attributes • Conceptualization and operationalization process can be seen as the specification of variables and the attributes composing them
Every variable must have two important qualities: • Attributes composing it must be exhaustive • Attributes composing a variable must be mutually exclusive.
Levels 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 measured • NOMINAL – also known as categorical or qualitative level variable – identifies variables whose values have no mathematical interpretation
ORDINAL – 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.
REMEMBER – 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.
Validity 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.
Face Validity • Face 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.
Content Validity • Establishes 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.
Construct Validity • Established by showing that the measure is related to a variety of other measures as specified in a theory. Criterion Validity • Established 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.
Reliability • Refers to whether or not you get the same answer by using an instrument to measure something more than once. Tests for Reliability • Test-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.
Split 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.