A. Measurement

Conceptualization and Operationalization

In evaluating information about the social world about any particular topic X, it is helpful to keep two questions in mind:

  1. "What is meant by X in this research?"
  2. "How was X measured?"

Researchers must develop answers to both questions before they proceed with their research. Singleton and Straits (1999) refer to the process of establishing a conceptual definition in addressing the first of these questions, while addressing the second is the creation of an operational definition.

These are also important questions to keep in mind as a savvy consumer of research as well. Say you are reading a study in the newspaper about the social and economic costs of substance abuse. As you read the article, you want to keep in mind what the authors mean by substance abuse in their research. Do they consider occasional pill use as substance abuse? Do they use a medical definition of a validated addiction?

And how do the researchers measure substance abuse? Do they interview respondents about their substance use, asking them about the number of days in the past week they used something? Do they count the number of days they missed work because of substance use? Or something else?

These questions are part of a more general topic of social science - conceptualization. Briefly stated, conceptualization is the process of specifying what is meant by a term. It involves taking portions of an abstract theory and translating them into testable hypotheses involving specific elements.

Think about the case of poverty. Poverty is the basis of a substantial volume of social science research. But researchers must create a specific conceptualization of the term poverty.

Criterion-Related Measure

There are a number of different ways that we might create specific, testable measures of poverty: We could employ a criterion-related measure. Perhaps the most common measure of poverty involves comparing family income against the "poverty line." This poverty measure was developed in the mid-1960s by researcher at the Social Security Administration (more on the history of the measure can be found here: http://aspe.hhs.gov/poverty/papers/hptgssiv.htm) and is defined in terms of the amount of money required to purchase an emergency amount of food a family needs and other essential goods. The current poverty thresholds can be found on the U.S. Department of Health and Human Services website: http://aspe.hhs.gov/poverty/03poverty.htm

Alternative Criterion

We could use an alternative criterion approach, one not comparing income against a scale, but one that asks about other criterion. An increasing number of studies use criterion measures related to elements of material deprivation. Since poverty reduces families' ability to pay for essential goods, we can get a measure of poverty by asking how often families had to do without certain things, such as food or clothing?

Related Measure

We could also create a relative measure of poverty, defining the lowest portion of an income distribution as living in poverty.

Subjective Approach

Or we could employ a subjective approach, asking individuals about how poor they feel. For some questions, it may be more important to know about whether people feel impoverished, relative to their peers, than to know about how their income compares to a threshold.

A similar concept involves taking these specific conceptualized constructs and translating them into specific measures that can be used to collect data about the social world, such as interview questions or a method of collecting information about income. This is a process called operationalization.

From these definitions, we can think about a two-stage process of social research: we begin with a concept, develop specific dimensions of interest through conceptualization, then create questions or specific measures through operationalization. Listed below are two examples of the process for poverty:

Concept Dimension of Interest Specific Questions or Measures
Poverty -> Absolute or "Threshold" Poverty -> "How much money did your family earn last year?" (followed by a comparison of this income to a threshold)
Poverty -> Subjective Poverty -> "How poor would you say you feel?"

There are many other different ways to ask about poverty besides these as well. We could ask individuals whether their family received food stamps or whether their children received free lunch at school (since food stamps and free lunch programs are only available to families who live below the poverty line). We could ask how often they went hungry or without another necessity (since, presumably, only those who could not afford such things would do without).

Decisions about which of these measures are best for a particular research project or study are driven largely by the specific elements most of interest to researchers. That is to say, typically the purposes of the study itself shape decisions about how to conceptualize and operationalize any particular topic.

However, there are other criteria to consider as well. The next section
of this lesson describes different dimensions of two characteristics of
measurement tools: validity and reliability.