Chapter 2 Research Methodology

Between-Subjects Design / two random-samples design

each subject is measured once, comparisons are made between TWO GROUPS of subjects

Within-Subjects Design / single group repeated-measures design

each subject is measured at least two times, comparisons are made within the SAME SUBJECT

Mixed Method / two-random-samples & repeated-measures design

a combination of between- and within-subjects design

Operational Definition

It translates abstract psychological constructs like "anxiety" into measurable terms, such as a test score or changes in heart rate

Operant Conditioning / Instrumental conditioning

a learning process where voluntary behaviors are modified by associating them with consequences, either rewards or punishment

Classical Conditioning

behaviors are learned by connecting a neutral stimulus with a positive one

Theory

explains how (mechanistic explanation) or why (functional explanation) something happens, or both how and why

Good Theory

a clear, internally consistent explanation of a psychological phenomenon, aligns with empirical data, can be tested and falsified, and generates new hypotheses

The role of a theory

integrates apparently unrelated facts and principles into a coherent whole

Narrative Review

a descriptive and subjective of the literature on a specific topic

Systematic Review

a structured and rigorous examination of the literature on a specific topic

Meta-analysis

an objective examination of published data from many studies of the same research topic identified through a literature search

Reliability

the consistency or dependability of a measurement tool or research finding

Random Errors

unpredictable differences between a measurement and the true value being measured

does not affect the average, only the variability around the average

Systematic Errors / Biases

in either the positive or negative direction consistently. They bias the overall measurement

does affect the average, shifting it to the right in this case. We call this a bias

Construct Validity

a test measures the concept it was designed to evaluate

Case Study / n = 1 study (number of observation = 1)

the intensive observation, recording and description of an atypical person, organization, or event

Correlational Studies

non-experimental research designs that explore the relationships between two or more variables, without manipulating or controlling them

positve correlation

negative correlation

no relation

Correlation Coefficient (also called Pearson’s r)

Independent Variable (X variable)

the experimenter controls

Dependent variable (Y variable)

the experimenter measures

Confounding variable (Third variable)

variable that affects a dependent variable and unintentionally varies between experimental conditions of a study

Internal validity

change in the dependent variable is caused by the independent variable and not by the confounding variables

External validity

generalize the findings of a study to other situations, people, settings, and measures, often from the lab to the real world

The control group / the placebo group (in a drug test)

a group of participants who do not receive the experimental treatment or intervention being tested

descriptive statistics

used to organize or summarize a set of data

inferential statistics

ways of analyzing data that allow the researcher to make conclusions about whether a hypothesis was supported by the results