Chapter 3 OutlineThree Claims, Four Validities:Interrogation Tools for Consumers of ResearchLearning ObjectivesKnow the Three Claims;Frequency, Association and CasualAsk the right questions in order tointerrogation each of the Four Validities;ConstructValidity, Statistical Validity, external Validity and Internal ValidityKnow whichvaliditiesare most relevant for each of thethree types of claims.Psychology research articles appear in our everyday reading and grab our attention with topicssuch as ADD and ADHD. These articles are simply reporting what the research was and why it isimportant however it isn’t always correct or accurate. We must learn how to interrogate andevaluate the information behind the study.Variables-Something that varies and it must have 2 values or levels.A Constant-could possibly vary however only 1 level in a study has.Measured and Manipulated VariablesMeasured Variable-levels are observedand recorded.Ex, height, weight, IQ, Bloodpressure-measured using scales, rulers or devices.Abstract Variable-is measured by recording a statement or observation or value as itnaturally occurs.ex;stress or depression levelsManipulated Variable-These are variables that you change on purpose in yourexperiment. It is what you are testingFrom Conceptual Variable to Operational Variable Definition--Two ways variable are described by researchers.Conceptual Variable- an abstract level such as, shyness or intelligence, also called aconstruct. Also known asconceptual definitions.Operational Definitions- the specific way in which a concept of interest is measuredor manipulated as a variable in a studyOperational Variables-to turn a concept of interest into a measured or manipulatedvariable.
Introduction
- You now have the tools to differentiate among the three major claims you will encounter in research
journals and in the popular media.
- Once you identify the kind of claim a writer is making, you need to ask targeted questions as a critically
minded consumer of information. The rest of this chapter will sharpen your ability to evaluate the claims
you come across using what might be called "the four big validities": construct validity, external validity,
statistical validity, and internal validity. In general, a valid claim is reasonable, accurate, and justifiable.
- In psychological research, we do not say that a claim is simply "valid". Instead, psychologists specify
which of the validities they are applying. You will learn to pause before you declare that a study is "valid" or
"not valid". Instead, you will learn to specify which of the four big validities the study has achieved.
- Although the focus for now is on how you can evaluate other people's claims based on the four big
validities, you will also use this same framework if you plan to conduct your own research. Depending on
whether you plan to test a frequency, an association, or a causal hypothesis, you will need to plan your
research carefully, in order to emphasize the validities that are most important for your goals.
Interrogating Frequency Claims
- To evaluate how well a study supports a frequency claim, you will usually need to ask about two of the big
validities: construct validity and external validity.
Construct Validity of Frequency Claims
- To ask about the construct validity of a frequency claim, the question to consider is how well the
researchers measured their variables. Take the claim "2 million U.S. teens depressed" for example.
- There are probably dozens of ways to evaluate whether a person is depressed. You could ask trained
therapists to clinically interview teenagers and assess which of them are depressed. You could ask study
participants to complete a structured, or a self-report questionnaire.
- When you ask how well a study measured or manipulated a variable, you are interrogating the construct
validity of the operationalization. Construct validity concerns how accurately a researcher has
operationalized each variable, be it depression, happiness, debt stress, gender, BMI, or self-esteem.
External Validity of Frequency Claims
- The second important question to ask about frequency claims concerns generalizability: How did the
researchers choose the study's participants, and how well do those participants represent the population
they are supposed to represent?
- External validity how well the results of the study generalize to, or represent, people and contexts
besides those in the study itself.
- To claim that half of Americans struggle to stay happy, the researchers in this study needed to ensure
that the participants adequately represented all Americans.
Interrogating Association Claims
Construct Validity of Association Claims - Association claims differ from frequency claims in that they
measure two variables instead of just one, and they describe how these variables are related to each other.
- For the headline "Heavy Cell Phone Use Tied to Poor Sperm Quality," you should ask how well the
researchers measured cell phone use and how well they measured sperm quality. For example, cell phone
use could be measured quite accurately using phone bills; a much less accurate measure would be
obtained by asking people to remember who much they use their cell phones.
- In any study, measurement of variables is a fundamental strength or weakness - and construct validity
questions assess how well such measurement was conducted. If you gather information on construct
validity and conclude that one of the variables was measured poorly, you would not be able to trust
conclusions related to that variable.