Operationalization

PSY 348: Lecture 2

Dave Brocker
brockeda@farmingdale.edu

Farmingdale State College

Studying Psychology

What do researchers in the areas of psychology that are interesting to you study?

Studying Psychology

What do researchers in the areas of psychology that are interesting to you study?

  • Attitudes

  • Beliefs

  • Behaviors

  • Physiology

  • Planning

  • Brain Activity

  • Thoughts

  • Performance/Ability

  • Attenton

  • Memory

Studying Psychology

The Bobo Doll Experiment (Bandura, 1961)

Operationalization

The process of defining the measurement of a phenomenon that is not directly measurable (AKA a latent variable) though its existence is implied by other phenomena.

How could we measure happiness?

Operationalization

Figuring out how to measure something you can’t directly measure.

  • Attitudes, Beliefs, Thoughts

  • Behaviors

  • Brain activity

  • Performance/Abilities

Operationalization

What if I wanted to measure religiosity?

What could I do, or what I could I ask?

Operationalization

  • Self-Report OR Behavioral Measures

  • Observation

  • Implicit Measures

  • Tests

Self-report

  • Surveys

  • Questionnaires

  • Polls

  • Quizzes

  • Instruments

Self-Report

What’s wrong with this?

Self-Report:

Advantages

  • Most popular method of assessing attitudes*

  • Can obtain large amounts of data

  • (Fairly) Quick

  • Allows for adaptive testing

  • (Fairly) Inexpensive

Self-Report:

Disadvantages

Acquiescence
  • Tendency to say yes, true, agree
Social desirability
  • Tendency to respond in ways that are seen as socially acceptable
Demand characteristics
  • Tendency to response in ways that participant thinks researcher wants

Self-report:

Avoiding Disadvantages

Anonymous respondents are less likely to make things up

Assure anonymity

Allow respondents to answer in private

Allow for maximum privacy

Don’t make your experiment too obvious/revealing

Obscure the true goal of the experiment

Add questions that test for respondent awareness

Include attention checks

Purposely make some questions opposite

Reverse coding

Behavioral Measures

  • Taking a flier

  • Signing a petition

  • Internet Behavior 1

  • Moving a chair

  • Donating money

Observation

The Bobo Doll Experiment (Bandura, 1961)

The Bobo Doll Experiment

(Bandura, 1961)

  • Live aggression by adult

  • Videotaped aggression by adult

  • Cartoon aggression

    • No aggression

Observation

Disadvantages

  • Time consuming

  • Different reviewers/observers may score behaviors differently.

    • Coding scheme

      • Who decides what is an example of the behavior?

    • Inter-rater Reliability

      • How much agreement is there between 2+ observers?

Implicit measures

Brain activity

  • Functional Magnetic Resonance Imaging (fMRI)

    • Neuroimaging of brain activity

  • Electroencephalography (EEG)

    • Electrodes on surface of scalp measures brain activity

Issues with Operationalization

Why is it hard to measure psychological phenomena?

  • Others may choose to measure the phenomena differently from us

  • Operationalization can be culture-specific

  • What we measure is based on observable parts of the phenomena, but some parts may be unobservable

    • Measuring only the observable/reportable is imprecise

Operationalization

How should we measure aggression in children?

  • Observer children for one hour and…

    • Label them as Aggressive or Non-Aggressive

    • Rank them from most aggressive to least aggressive

    • Score them on a 10-point scale.

      • 1 = No Aggression

      • 10 = All of the Aggression

    • Count number of aggressive behaviors

Scales of measurement

A Scale By Any Other Name

  • Labels Nominal

  • Rank Order

  • Scale Interval

  • Count Ratio

Measurement scales: Nominal

Qualitative

Nominal refers to categories that CANNOT be ordered:

  • Condition (experimental, control)

  • Gender

  • Major in college

  • Coffee drinker versus Non-coffee drinker

  • Android User or iPhone User

Measurement scales: Ordinal

Quantiative, No Equal Steps

Ordinal refers to categories that CAN be ordered, but the space between each category isn’t the same:

  • Olympic Medals

  • Winner in a Race

  • Your rank in this class

  • Your top 10 Movies

Ordinal Scales

  • Rarely used in psychological research, because it is hard to calculate variance when the interval between each number differs.

  • There are non-parametric statistics designed for ordinal scales, but we will not be covering those this semester.

Measurement scales: Interval

Quantitative, Equal Distance, No True 0

Interval refers to ratings that are ordered where the interval between each rating is the same, but there is no real “0.”

  • Temperature*

  • “On a scale of 1-10 How much do you agree with the following statement…”

  • GPA

Measurement scales: Ratio

Quantitative, Equal Distance, No True 0

Ratio, refers to ratings that are ordered, the interval between each rating is the same, and “0” means “0.”

  • Length

  • Reaction Time

  • Dosage

  • Money Donated

Interval vs Ratio

What’s the difference between interval and ratio?

  • Interval may have a 0 on the scale, but it doesn’t mean the absence of something. A 0.0 GPA means an F rather than the absence of a grade.

  • Ratio has a 0 that. means 0 (the absence of something), like a ‘0’ as a response to the questions, “How many drinks did you have last night?”

Discrete and Continous

What’s the Difference?

Discrete variables have predefined values

  • US States

  • Flavors of Ice Cream

Continous Variables can occupy several different values

  • Reaction Time

  • TV Ratings

Determining Scale of measurement

Identify the scale of measurement.

Undergraduates report their self-esteem on a scale of 1 to 10. Researchers assess the relationship of undergraduates’ self-esteem and GPA.

  • Predictor variable: Self-Esteem | Continuous (Interval)

  • Outcome variable: GPA | Continuous (Interval)

Determining Scale of measurement

Identify the scale of measurement.

Participants are given a mystery drug or placebo and then asked to complete puzzle tasks. Researchers time how long participants take to complete the puzzles.

  • Independent variable: Drug vs. Placebo | Categorical (Nominal)

  • Dependent variable: Reaction Time | Continuous (Ratio)

Determining Scale of measurement

Identify the scale of measurement.

Undergraduates are shown either pictures of death or pictures of landscapes. They then report their anxiety about aging on a scale of 1 (none) to 10 (lots).

  • Independent variable: Pictures of death versus landscapes | Categorical (Nominal)

  • Dependent variable: Anxiety about dying | Continuous (Interval)

Why does scale of measurement matter?

For Science!

  • Statistical tests can only be run on specific scales of measurement.

  • t-test & ANOVA: Nominal IV/predictor and Continuous DV/outcome

  • Correlation & Regression: All continuous

Why does scale of measurement matter?

  • Generally, continuous variables (interval and ratio scales) lend themselves better to statistical analysis.

  • As a researcher, you should plan out your statistical analysis BEFORE conducting your study, so that you measure your variables in a way that matches the type of analyses you will run.

TAKE AWAY: How we measure variables matters…

because it dictates what kind of statistical analyses we can run.

  • Data can be coerced into different formats

  • ‘Correct’ or ‘Supporting’ results can come from bogus data

Statistical Terms & Symbols

Statistical Terms

Population

Every person in the group I am interested in studying

Sample

A small subset of people from the population who we will actually study in our experiment.

Parameter:

Information about the population.

Statistic

Information about the sample.

Statistical Symbols

Case-sensitive and often Greek

  • \(n\) = the number of people in the sample

  • \(x\) = one datapoint in a sample

  • \(\bar{x}\) = Arithmetic mean (average) for a sample, x

  • \(\Sigma(x)\) = The sum of all values in a sample, x

  • \(\sum^{n}_{i = 1}= x_1 +x_2+x_3...\)

Practice 1

Study Up!

Esmeralda is taking Statistics for the Psychological Sciences. On her first exam, she scored 98. The average grade among the 26 students on that exam was 97

n:

x:

\(\bar{x}\)

Practice 2

You Ever Hear of this show?

Professor Brocker is interested in how many Farmingdale students watch the Netflix Original, Dark. He plans to ask 200 students if they have seen it or not.

N:

n:

Scale of Measurement:

Practice 3

Be Kind to Yourself!

A research study surveys 500 college student across 5 campuses in the United States, asking them to rate their self-esteem on a scale of 1 to 10.

Sample:

Population:

Scale of Measurement: