Psychology Research Methods and Statistics

A comprehensive set of vocabulary flashcards covering research modules, study designs, sampling techniques, ethical principles, and descriptive statistics based on the lecture transcript.

Construct

An intangible attribute or hypothetical psychological mechanism that cannot be easily observed, such as happiness or intelligence.

Operationalism

The process of making constructs measurable within a research study.

Operational definition

The process of defining and measuring an unobservable construct indirectly through a specified measurement procedure.

Research question

The broad question, idea, or problem a researcher wants to investigate, typically categorized as relating to association, difference, or prediction.

Hypothesis

A testable, refutable, and predictive statement about what will happen in a psychological research study, usually following a literature review.

Variable

A characteristic or condition that can change and take on different values.

Independent variable

The variable thought to be causal or influential in the hypothesized relationship being investigated.

Dependent variable

The variable that is affected or influenced by an independent variable.

Continuous variable

A variable that allows for decimals and fractions in its measurement.

Discrete variables

Variables consisting of separate, indivisible categories that allow only whole values with no decimals or fractions.

Nominal scale

A scale of measurement based on a set of categories with no intrinsic ordering, such as gender.

Ordinal scale

A scale where values are assigned to indicate an order, but which does not indicate the magnitude of difference between points, such as podium positions in a race.

Interval scale

A scale where numbers indicate an actual amount with equal units separating scores, but without a real zero point, such as temperature in Celsius where $0^{\text{o}}C$ does not mean an absence of heat.

Ratio scale

A scale where numbers indicate an actual amount with equal units and a real zero point, such as the distance between two objects.

Research design

The format and strategic structure of a research project, outlining how the project progresses over time.

Descriptive research design

A design concerned with the measurement and description of individual variables in their natural state without manipulation.

Correlational research design

A design that investigates the relationship between two variables within one group of people to gather evidence about association, but not cause and effect.

Experimental research design

A design that determines cause and effect by manipulating an independent variable and using carefully controlled conditions and random assignment.

Internal validity

The degree of confidence in a direct relationship between the independent and dependent variable, strengthened by controlling conditions.

Quasi-Experimental research design

A design that seeks to investigate cause and effect with attempts to control extraneous variables, but lacks random assignment of participants.

Non-experimental designs

Designs concerned with observing relationships between variables by comparing two or more groups of people on a single variable without explaining cause and effect.

Population

The entire group of individuals of relevance to a research study.

Sample

A small number of people drawn from a population to participate in a research project.

Probability sampling

Sampling techniques applied when precise details of the population are known and the probability of any individual being selected can be determined.

Simple random sampling

A selection process where each individual in the population has an equal probability of being selected, ensuring freedom from selection bias.

Non probability sampling

Sampling where the probability of selecting an individual is unknown, often used when population characteristics are unknown.

Convenience sampling

A non-probability sampling method involving individuals who are easy or convenient to recruit, which is often vulnerable to sampling bias.

Quotas

Identification of subgroups in the accessible population to set recruitment goals, ensuring subgroups are equally represented in the sample to control sampling bias.

NHMRC

The National Health and Medical Research Council, which provides guiding principles for the conduct of psychological research.

Merit

A core principle where research is justified by potential benefit to humanity and is scientifically sound in methodology.

Integrity

A core principle requiring research to be performed according to well-founded principles and findings to be reported honestly.

Justice

A core principle ensuring equal inclusion/exclusion of participants, fair distribution of benefits, and avoiding unfair burdens or exploitation.

Beneficence

A core principle where researchers minimize risks and ensure likely benefits justify any risk or discomfort to participants.

Respect

A core principle involving regard for participants' culture, beliefs, welfare, and privacy, empowering them to make decisions about participation.

Frequency distribution

An organized display of scores, often in a graph or table, showing the number of individuals located at each point on the scale of measurement.

Box plot

A data visualization where the top section above the box represents the highest $25\%$, the box represents the middle $50\%$, and the section below represents the lowest $25\%$, with outliers marked outside the lines.

Positively skewed distribution

A distribution where the bulk of the data is to the left and there is a long right tail.

Negatively skewed distribution

A distribution where the bulk of the data is to the right and there is a long left tail.

Central tendency

A statistical measure that identifies the most typical score in a distribution.

Mean

The average score, calculated by adding all scores and dividing by the number of scores ($N$); it is affected by outliers.

Median

The middle score in an ordered distribution; it is unaffected by outliers and used with ordinal scales or skewed data.

Mode

The most frequently occurring score in a distribution, used with discrete data and nominal scales.

Variability

A measure of how scores are spread throughout a distribution of data.

Range

The distance covered by the entire distribution, calculated as $X_{max} - X_{min}$.

Interquartile range

The distance in a distribution between the first quartile ($25\%$\text{ mark}) and the third quartile ($75\%$\text{ mark}).

Standard deviation

The square root of the variance, representing the average amount that scores deviate from the mean.

Deviation score

The result of subtracting the mean from a raw score; the sum of all deviation scores in a distribution is always $0$.

Sum of squares

The sum of the squared deviation scores used in the calculation of variance.

Variance

The sum of squares divided by the degrees of freedom ($N-1$).

Degrees of freedom

Represented as $N-1$, where $N$ is the sample size; used in the calculation of variance.

Critical thinking

An active process of scrutiny used to evaluate arguments and data.

Deductive argument

An argument that starts with broad premises to reach a specific conclusion; it is valid if the conclusion necessarily follows from the premises.

Inductive argument

An argument that moves from specific observations to general conclusions; it is considered strong if the premises provide good support for the conclusion.