Research Methods and Statistics
W1.1
CHAPTER 3 – THREE CLAIMS, FOUR VALIDITIES: INTERROGATION TOOLS FOR
CONSUMERS OF RESEARCH
Variable: Something that can be changed or altered, such as a characteristic or value – Must
have two levels
Constant: Something that could potentially vary, but has only one level in the study of
question
↓
E.g.: ‘15% of Americans smoke’ → ‘Nationality = Constant; ‘Smoking’ = Variable; ‘Smoker
and nonsmoker’ = Levels of the variable
Measured variable: A variable whose measures are simply observed and reported
Manipulated variable: A variable that is controlled by researchers, usually by assigning study
participants to the different levels of that variable – Some variables can only be measured and
not be manipulated because of ethical reasons, or because it is impossible to manipulate them
(such as IQ of age)
Conceptual variable/construct: Abstract concepts that must be carefully defined at the
theoretical level; the conceptual definition (E.g.: spending time socialising; school
achievement)
Operational variable: A conceptual variable that is turned into a measured or manipulated
variable (E.g.: researchers ask people how often they spend an evening alone, socialise with
friends or see relatives in a week)
Claim: An argument that someone is trying to make
- Frequency claim: Describe a particular degree of a single variable; how frequent or
common something is (E.g.: 15% of Americans smoke) – Accompanied by a margin
of error of the estimates – Observational research
- Association claim: Argues that one level of a variable is likely to be associated with a
particular level of another variable – Variables are said to correlate or to be related –
When one variable changes, the other variable tends to change too (E.g.: people with
higher incomes spend less time socialising) – Type of study involved with association
claims is a correlational study – Uses words like ‘link’, ‘correlate’, ‘predict’, ‘tie to’,
correlate’ and ‘being at risk for’ - Type I error: False positives – Type II error: False
negatives
1. Positive association
2. Negative association
3. Zero association
- Causal claim: Argues that one variable is responsible for changing the other (E.g.:
music lessons enhance IQ) – Uses words like ‘affect’, ‘change’, ‘enhance’ and ‘cause’
– Can be supported by experiments in which the independent variable is manipulated
, and the dependent variable is measured – Outcome is best ensured through random
assignment
1. Covariance: Two variables are correlated
2. Temporal precedence: The causal variable came first and the outcome variable
came later
3. Internal validity: No other explanation can exist for the relationship
Validity: Refers to the appropriateness of a conclusion – Does the measurement measure what
it is supposed to measure?
- Construct validity: How well is the conceptual variable operationalised? – Entails
reliability (= does the measurement yield similar scores on repeated tests?)
- Statistical validity: The extent to which a study’s statistical conclusions are accurate
and reasonable
- Generalisability/external validity: How well do the results of a study generalise to, or
represent, people besides those in the original study? – Important in frequency claims!
CHAPTER 6 – SURVEYS AND OBSERVATIONS: DESCRIBING WHAT PEOPLE DO
Survey: Used when people are asked about a consumer product Method of posing
questions to people
Poll: Used when people are asked about their social or political opinions
- Leading questions: Questions that potentially could lead people to a particular
response
- Double-barrelled questions: Questions that ask two different things in one
- Negative wording: Using double denial makes questions unnecessarily difficult
- Question order
Response sets/nondifferentiation: Shortcuts respondents may take when answering a survey
- Acquiescence/yea-saying
- Fence sitting
- Socially desirable responding – Faking good / Faking bad
Observational research – Can be better than self-report measures
- Observer bias: When observers’ expectations influence their interpretation of the
participants’ behaviour or the outcome of the study
- Observer effects (E.g.: Clever Hans)
- Reactivity: When people know they are being observed, they behave differently
Can be prevented by masked design/blind
design, unobtrusive observations or
habituation
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper lottepeerdeman. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €7,49. Je zit daarna nergens aan vast.