Design, Measurement, Information Sources Conceptualization What is a concept? Dimensions of a concept Indicators of a concept Validity and reliability of indicators Operationalization Factors to consider Levels of measurement

Concept = mental image Name for a category of things General, abstract Meaning is agreed upon by a group no $, run-down apt., welfare, mom w/ kids, minority, … “Poverty” =

Examples of sociological concepts Society Culture Social structure Social institution Primary group Formal organization Deviance Social control Social class Socioeconomic status Poverty Inequality Prejudice Minority group Social distance Liberalism Value of children Marital satisfaction Religiosity Social movement

Nominal definition Gives researcher’s definition of a concept Not exact or specific Distinguishes it from similar concepts Violence is any kind of maltreatment. Violence is a physical act that causes injury. Violence is a physical act that is intended to cause injury. Violence is an act that is intended to cause injury or pain, no matter how minor. Love is attachment. Love is a very strong liking. Love is a romantic and sexual attraction to another person. Love is putting another’s needs before your own.

Dimension Love Part or aspect of a concept Component of a concept Not the entire concept in itself Love Commitment Intimacy Passion

Researchers may disagree about dimensions of a concept: Love Caring Attachment Sexual attraction OR: Love Attachment

4 Conceptualizations of Inequality SES Status Education Earnings Occupation Prestige Class SES Power Wealth Relationship to means of production Prestige Knowledge

Indicators of a Concept Measurable, observable variables Indicate presence or absence of concept At least one indicator per dimension indicator = “clue” to a concept

Example: Indicators of Love Attachment: “I would not like to live without .” “When is gone, I feel like part of me is missing.” Intimacy: “ and I are very close.” “ I can share my feelings with .” “I trust .” Caring: “I put ‘s needs before my own.” “ I want to be happy.”

Example: Indicators of Social Stratification Status, prestige: Admiration of others, ranking of occupations by public. Wealth: Income, assets Knowledge: Yrs. of education, degree Power: Positions in organizations Class, relationship to means of production: Owns business Has employees Controls others’ labor (hire/fire, make rules, etc.) Sells own labor

Operational definition vs. Similar Terms The specific definition of a concept that is used in a particular study May involve exact wording of a measure Indicators can have more than one operational definition “Variable” may refer to an indicator or operational definition

Examples: Operational Definitions of “Income” Individual’s (or couple’s) gross annual income before taxes, as reported on tax return. “Would you say your income last year was between: 0 – 19,999; 20,000 – 39,999; 40,000 – 49,999….” Total family income from all sources Top 25%, middle 50%; bottom 25%

Examples: Operational Definitions of “Unemployment” % of people who are not employed % of people 16-64 who are not employed % of people 16-64 who are looking for work % of people 16-64 looking for work or who gave up looking…

Level of measurement No No No Yes No No Yes Yes No Yes Yes Yes Yes Yes Nominal Ordinal Interval Ratio Meaningful zero point No No No Yes Numerical values; equal distances b/t categories No No Yes Yes Rank categories in order No Yes Yes Yes Name categories, count frequencies Yes Yes Yes Yes

Examples of nominal variables Gender (Male/Female) Race (White, Black, Hispanic, Asian, Native American, other) Political preference (Democrat, Republican, other) Occupation (job title) Favorite breakfast cereal State of residence

Examples of Ordinal Variables Opinion statement (strongly agree, agree, don’t know, disagree, strongly disagree) Social class (lower, working, middle, upper) Level of education (< high school, high school grad, vocational/technical degree, bachelor’s degree, graduate degree) Church attendance (never, several x/year, monthly, weekly)

Examples of Interval Variables (Numeric, but scale is arbitrary) Temperature (Celsius, Fahrenheit) IQ score (average = 100) Occupational prestige (0 – 100) Rating scales (0-5, 1-10, etc.) Any numerically scaled variable

Examples of ratio variables Income in dollars Years of education Age in years Number of children Population size Rates (births, deaths, crimes, etc.)

What is the level of measurement? Marital status (never married, married, separated, divorced, widowed) Market value of home (dollars) Approval of president’s job performance (strongly approve, approve, disapprove, strongly disapprove) Grade point average (0.0 – 4.0) Letter grade (A, A-, B+, B, B-,….) Marital satisfaction (scale of 0 – 10) Participation in extracurricular activities (Yes/No)

Evaluating Indicators: Validity Validity = “Truth” Are we measuring what we think we’re measuring? Does the indicator really reflect the concept?

Ways to evaluate validity Face validity: does it make sense? Agrees best judgment, or opinion of experts. Example: Makes sense to use income as a measure of social position. Predictive (criterion) validity: does it work? Is it a good predictor? Example: ACT score is a predictor of college GPA

Ways to evaluate validity Content validity: Does indicator cover all the dimensions of the concept? Example: Measure of “risk taking” must include attitudes (enjoy taking risks) and behaviors (actually takes risks). Construct validity: Does the indicator behave as expected? How is it related to other indicators of other concepts? Example: Measure of “marital stress” should correlate positively with divorce, negatively with measure of marital satisfaction.

Evaluating Indicators: Reliability Reliability = dependability Freedom from measurement error Measure yields the same results every time.

Reliability ≠ Validity We can measure accurately without reflecting the underlying concept. Examples of reliable but invalid indicators: Foot size as indicator of intelligence Race as indicator of criminal behavior Number of children as indicator of masculinity Age as indicator of wisdom Length of marriage as indicator of satisfaction

What causes measurement error? Poorly designed measure Respondent or subject People working with measure Changes over time

Measuring Reliability: most common methods Internal Consistency – correlation between several indicators of the same concept Test-retest – same measure applied twice should yield same results Reliability coefficient = results of a reliability test. Range from 0-1.0. Should be very high (> .9) if measure is reliable.

Maintaining Reliability Careful wording of survey questions Ask questions R’s can answer Pretest questions or measures Train people who will work with measures (e.g. interviewers, coders) Be cautious of variables that change over time.