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 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 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.