Adler clark 4e ppt 06

Measurement

Chapter 6

Introduction

Measurement Classifying units of analysis by categories to

represent variable concepts Example

You may classify individuals into the categories, such as--satisfied with life or not satisfied with life--to represent the variable concepts of life of satisfaction

Introduction

Quantitative research Research focused on variables, including their

description and relationships

Introduction

Qualitative research Research focused on the interpretation of the

action of, or representation of meaning created by, individual cases

Introduction

Measure A specific way of sorting units of analysis into

categories

Introduction

The concepts in social science research can often be difficult to measure Concept examples

Feelings regarding fatherhood, satisfaction with life, suicide, and power

Measurement is a way to define a concept

Conceptualization

The process of clarifying what we mean by a concept

Conceptualization

Conceptual Definition A definition of a concept through other

concepts

Conceptualization

Concepts Words or signs that refer to phenomena that

share common characteristics

Conceptualization

Dimensions If a concept is so large that it may need to be

divided into different aspects or dimensions to further clarify it

Dimensions are aspects or parts of a larger concept

Conceptualization

Multidimensionality A concept that refers to a phenomenon that is

expected to have different ways of showing up or manifesting itself is said to be multidimensional

Multidimensionality is the degree to which a concept has more than one discernible aspect

Operationalization

The process of specifying what particular indicator(s) one will use for a variable

Operationalization

Indicators Observations that we think reflect the

presence or absence of the phenomenon to which a concept refers

Operationalization

Example – Age Conceptualize age – as chronological age Still need to determine an operational

definition

1. Are you old?

2. How old are you? Circle the letter of your age categorya. 25 or younger b. 26 to 64 c. 65 or older

3. How old are you?

Operationalization

Operationalization involves providing operational definitions Declarations of how a specific phenomena

described by concepts are determined for a specific instance.

Operational Definitions

Example – age Several ways to conceptualize age

Chronological age (time since birth) Functional age (the way people look or the things

they can do) Life stages (adolescence, young adulthood, and

so on)

Operationalization

An Example of Conceptualization and Operationalization Quality of Life Measure Study interested in quality of life and how

stress and coping resources affect life satisfaction, with a particular interest in comparing younger, middle aged, and older adults

Operationalization

Index A composite measure that is constructed by

adding scores from several indicators

Operationalization

Operationalization

Composite Measures A measure with more than one indicator Designed to solve problems of ambiguity that

are associated with single indicators by including indicators of a variable in one measure

Operationalization

Composite measure Scale

Indexes in which some items are given more weight than others in the determination of the final measure of a concept

Quiz – Question 1

Professor Johnson is interested in examining the connection between age at first sexual experience and high school completion. Which of these concepts must be operationalized?

a. First sexual experience

b. High school completion

c. College enrollment

d. A and B

e. None of the above

Focal Research

“Impostor Tendencies and Academic Dishonesty” How is the impostor phenomenon

conceptualized by Ferrari and by other social psychologists?

Are you surprised by this way of thinking about “impostors”?

Focal Research

Thinking about ethics Students were given informed consent forms

to sign before they were asked to fill out Ferrari’s questionnaire.

By not putting their names on the questionnaires, the anonymity of respondents is guaranteed.

Focal Research

Measurement error The kind of error that occurs when the

measurement we obtain is not an accurate portrayal of what we tried to measure

Measurement in Visual Analysis and Qualitative Research Visual analysis

A set of techniques used to analyze images] refers to a set of techniques used to analyze images

Measurement in Visual Analysis and Qualitative Research Coding

Assigning observations to categories

Exhaustive and Mutually Exclusive Categories Exhaustive

The capacity of a variable’s categories to permit the classification of every unit of analysis

Exhaustive and Mutually Exclusive Categories Mutually exclusive

The capacity of a variable’s categories to permit the classification of each unit of analysis into one and only one category

Quiz – Question 2

What is the problem with the following survey response set for the question “how old are you”?

25 or less 25 to 65 65 and older

a.The concept is not operationalizedb.The response set is not mutually exclusivec.The constructs are multi-dimensionald.The conceptual definitione.None of the above

Quality of Measurement

Reliability & Validity Reliability - the degree to which a measure

yields consistent results A measure is reliable if it yields consistent results

time after time Validity – the degree to which a measure taps

what we think it’s measuring A measure is valid if you measure what you think

your are measuring


Checking Reliability A yard stick will consistently measure 30

inches time after time, so it is reliable—but it is possible to have the first inch sawed off, so we need to check reliability.


Checking Reliability Test-retest method Split-half method Interobserver Reliability Interrater Reliability method


Checking Reliability Test-retest

A method of checking reliability of a test that involves comparing its results at one time with results, using the same subject at another time


Checking Reliability Test-retest

Measuring the width of a desk two or more times in close succession with the same yard stick

Problems: Phenomenon under investigation might actually

change between the test and the retest – change in life satisfaction

Earlier test results may influence you the second time you test


Checking Reliability Split-half method

A method of checking the reliability of several measures by dividing the measure into two sets of measures and determining whether the two sets are associated with each other.

Deals with the problems of the test-retest method Making more than one measurement of a

phenomenon at the same time


Checking Reliability Interobserver reliability method – compares

the results obtained by one observer with results obtained by another using exactly the same method.

Assessing the traits of individual characters in children's’ books using a pre-defined measurement scheme, they agreed 88 percent of the time on average

Quiz – Question 3

If we administer a survey to measure school-related stress and re-administer it one month from today to the same group and obtain different results, what does this indicate to us about our measurement?

a. It may not be a reliable measureb. Stress may have changed in the groupc. We may need to re-administer the survey again to determine

more conclusively if the measure is reliabled. All of the abovee. None of the above


Checking Validity Does this measurement strategy feel as if it’s

getting what it is supposed to?

Face validity Content validity Predictive validity Construct validity


Checking Validity Face Validity

The degree to which a measure seems to be measuring what it’s supposed to be measuring


Checking Validity Content validity

How well a measure covers the range of meanings associate with a concept

If most people know something about a concept, feel that a given set of questions “gets at” that concept and the set of questions asked about a question cover the usual range of “content” implied by the concept


Checking Validity Predictive validity

How well a measure is associated with future behaviors you would expect it to be associated with

Involves comparing the results of your measurement scheme with a criteria variable that it should predict

Example Compare the SAT scores of high school seniors with their

performance in college and found that students with higher test scores did better in college, then you could say the SAT test has predictive validity


Checking Validity Difficult to validate social science measures

using behavioral criteria, b/c limited in finding behaviors that they obviously predict to

Many of the social science indicators are meant to measure abstract concepts

Social scientists tend to use construct validity


Construct Validity How well a measure of a concept is

associated with a measure of another concept that some theory says the first concept should be associated with

Level of Measurement

Nominal level variables Describes a variable whose categories have

names Nominal level variables permit us to sort our

data into categories that are mutually exclusive


Nominal Level Variables Said to be the lowest level of measurement,

b/c it is virtually impossible to create a variable that is not nominally scaled

Examples Sex (Male, Female) Religion (Christian, Muslin, Jewish, Other) Cause of Death (Suicide, Homicide, Accident)


Ordinal Level Variables Describes a variable whose categories have names

and can be rank-ordered in some way Example

Social Class (upper, middle, lower) Ordinal level variables guarantee that categories are

mutually exclusive and that the categories can be ranked

All ordinal variables can be treated as nominal, but not all nominal variables may be treated as ordinal

Sex vs. Age


Interval Level Variables Describes a variable whose categories have names,

can be ranked-ordered, and whose adjacent categories are a standard distance from another

All interval variables can be treated as nominal or ordinal variables, but ordinal and nominal variables cannot be treated as interval


Interval Level Variables Categories of interval variables can be

meaningfully added and subtracted Fahrenheit temperature scale SAT score

The difference between 550 and 600 on the math aptitude test can be seen as the same as the difference between 500 and 550


Ratio level variables Describes a variable whose categories have names,

can be rank-ordered, has a standard distance from another AND HAS AN ABSOLUTE ZERO

Absolute zero is the point at which there is a complete absence of the phenomenon in question

Examples Weight Income Length

Ratio level variables can also be interval, ordinal, and nominal level variables

Quiz – Question 4

Letter grades given at the end of the term are an example of _____________ measurements; calculated GPAs are a type of _________________ measurements.

a. ordinal, interval

b. ordinal, ratio

c. interval, ratio

d. Nominal, ratio

e. None of the above

Quiz – Question 5

A researcher designs a survey question asking respondents to indicate their class standing as either: First-Year, Sophomore, Junior, Senior, or Graduate School.

a. nominal

b. ordinal

c. interval

d. ratio


The practical significance of level of measurement Researchers find themselves wanting to summarize

the information that has been collected Certain statistics require different levels of

measurement Three ways to describe central tendency

Mean – interval, ratio Median – ordinal Mode - nominal


Given a choice, measure a variable in a higher level of measurement than a lower one

The higher the level of measurement, the more statistics that can be performed on the data

Summary

The importance of measurement

Adler clark 4e ppt 06

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