Experiemntal Psychology review test 1

What is science?

A system of knowledge based on the scientific method.

Systematic empiricism

Learning through structured observation.

What makes scientific knowledge special?

It's testable, shareable and can be verified by others

What are the goals of science?

Describe, predict determine causes, and explain behavior

Falsifiability

A good theory can be proven wrong through evidence

What can't you ever prove in science?

A theory — you can only support or reject it

Hypothesis

A testable prediction derived from a theory.

What are features of a good theory

Productive, falsifiable, and simple (parsimonious).

Independent Variable (IV)

The variable manipulated by the researcher.

Dependent Variable (DV)

The outcome measured to see the effect of the IV.

What is confounding variable ?

An extra variable that affects both the IV and DV

Why assign numbers to variables?

For objective comparison of individual differences

What are the four measurement scales

Nominal, ordinal, interval, and ratio

Reliability

Consistency of a measure

Validity

Accuracy- measuring what you intend to measure

What are three main forms of reliability?

Test- retest, internal consistency, and inter-rater

What are the two main forms of validity?

Internal (control) and external (generalizability)

If a computer flickers during an experiment, what’s affected?

Internal validity

What is correlational research?

Examines relationships, not cause and effect

What is experimental research?

Tests cause and effect using manipulation and control

Third variable problem

A hidden factor influences both variables

What does “regression to the mean” mean?

Extreme scores tend to move toward average on retesting

What do moderators and mediators explain?

Moderators= when/for whom; Mediators- how/why

Between- subjects design means

Different people in each condition

Within-subjects (repeated measures) means

Same people experience all conditions

What helps control order effects?

Counterbalancing or Latin square

Benefits of repeated measures?

More sensitive, fewer participants needed

What’s the difference between probability and nonprobability sampling?

Probability=random; Nonprobabilty= confidence/purposeful

Self-report measure

Data from participants own responses (like surveys)

Behavioral measure

Observing performance or actions

Physiological measures

Brain or body responses (EEG, MRI)

EEG (Electroencephalogrpahy)

Tracks brain waves; great timing, poor location info

ERP (Event- Related Potentials)

Brain’s quick response to a stimulus

fMRI

Measures blood-oxygen changes; great spatial, poor temporal

TMS (Transcraniall magnetic Stimulation)

Uses magnetic pulses to temporarily disrupt brain activity

What’s a downside of fMRI

Loud, expensive, poor timing info

What’s a risk of TMS?

Muscle spasms or rarely seizures

What’s a ceiling effect?

Scores clusters at the top- DV too easy

What’s floor effect?

Scores cluster at the bottom- DV too hard

What are the four main measurement scales?

Nominal, Ordinal, Interval, Ratio

What does a Nominal scale measure?

Categories with no order (like gender, type of car)

What does an ordinal scales measure ?

Ranked order, but not equal intervals (like class rank or satisfaction levels)

What does an Interval scale measure?

Equal intervals, but no true zero (like temperature in F)

What does a Ration scale measure?

Equal intervals and a true zero (like height, weight, or age)

A professor records the number of times each students misses class. What scale is “number of absences"“?

Ratio- because zero means non and differences are equal

Letter grades (ABCDF) represent what scale?

Ordinal- they show rank order, not equal intervals

Room temperature ind egress Fahrenheit is measured on which scale?

Interval- equal units, but zero doesn’t mean “no temperature”

“Type of bicycle” (Road, Mountain, Cruiser) is measured on what scale?

Nominal- just categories no ranking

Which two scales allow for mean and standard deviation calculations?

Interval and Ratio

Which scales are qualitative, not numerical

Nominal and Ordinal