Concepts and Variables

8/30/2012

Readings

• Chapter 1 The Measurement of Concepts (14-23) (Pollock)

• Chapter 2 Measuring and Describing Variables (Pollock) (pp.28-31)

OPPORTUNITIES TO DISCUSS COURSE CONTENT

Office Hours For the Week

• When– Friday 11-1– Tuesday – And by appointment

Course Learning Objectives

1. Students will learn the research methods commonly used in behavioral sciences and will be able to interpret and explain empirical data.

2. Students will learn the basics of research design and be able to critically analyze the advantages and disadvantages of different types of design.

CONCEPTSThe First Steps in Measurement

What are Concepts?

• Concepts are the words we use to describe political, social and environmental behaviors

• They name and describe the external world

The Conceptual Definition

• This is the conceptual definition takes abstract things and make them real.

• States the concept in unambiguous terms

• Must communicate– The variation within a concept– The subject to which the concept applies

Types of Concepts

• Socio-economic

• Attitudinal

• Behavioral

• Environmental

The Operational Definition

• Turning your concept into something that can be measured

• Must be precise and accurate

• This can be very difficult

The Operational Concept of Organic

The Concept of Poverty

Absolute Depravation• The Federal Government

sets the poverty guidelines

• This is then used to determine eligibility for benefits

Relative Depravation

2012 Poverty Guidelines for the48 Contiguous States and the District of Columbia

Persons infamily/household Poverty guideline

1 $11,170

2 15,130

3 19,090

4 23,050

5 27,010

6 30,970

7 34,930

8 38,890

For families/households with more than 8 persons,add $3,960 for each additional person.

Definitions must match

When Concepts and Operations do not match

THE SECOND STEP: VARIABLESMeasurement

What are Variables

• These are simply measured concepts

• This is called operationalization

• Good variables take on all values of a concept

Variable measurement

• constants

• Dichotomous Variables

• The rest

The Dependent Variable

• The variable in a relationship you want to explain. The Y variable

• There is only one of these in a relationship

• It changes in response to an independent variable

The Independent variable

• Variables that that cause change in the dependent variable

• The (X) variable

• You may have more than 1 of these

The Relationship Between them

Telling the Difference between I.V.’s and the D.V.

Additive Relationships

• Most Social Science relationships involve many i.v.’s…. Why?

• Explaining a Dependent variable with more than 1 independent variable is called an additive relationship!

Additive Relationships

Antecedent and Intervening Variables

Antecedent• Come before the

independent variable

• Things like Demographics

Intervening• Come in-between the IV

and the DV

• Temporal events

How they can influence relationships

A Spurious Relationship• What antecedent variable might be at play?

UNITS OF ANALYSISHow we measure our Variables

Units of analysis

• The unit about which information is collected and that provides the basis of analysis

• Each member of a population is an element

• Why they are important?

Individual Unit

• The lowest form of data

• People, congressmen, presidents, etc

Aggregate Data

• A collection of individual level units

• Often measured in percentages

• Footprints

The Poor over Time

Immigration over time

The Problem of Access

FALLACIES MADE WITH DATA

Ecological Fallacy

• this arises when an aggregate/ecological level phenomenon is used to make inferences at the individual level.

• Taking statewide data and applying to individuals

• Does everyone in MS go to church?

The Exception Fallacy

• taking one person's behavior, attributes, etc and applying it to an entire group

• Using 1 example to define group behavior

Examples from Texas Style