Conceptualization and Measurement MEASUREMENT PROCESS Begins when the

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.