Stats Chpt 1

Vocabulary terms and definitions covering the fundamental concepts of statistics, research design, and data ethics based on the lecture transcript.

Descriptive statistics

A branch of statistics used to organize, summarize, and communicate a group of numerical information, including means, medians, range, and standard deviation.

Inferential statistics

A branch of statistics that uses sample data to make estimates about the larger population using methods such as t-tests, ANOVAs, correlations, and regressions.

Population

All possible observations about which we would like to know something, such as all Wisconsin college students.

Sample

A set of observations drawn from the population of interest, such as a group of $200$ UWSP students.

Variables

Any observation of a physical, attitudinal, or behavioral characteristic that can take on different values.

Levels

The discrete values or conditions that variables can take on, such as $1 = \text{Wisconsin resident}$ and $2 = \text{Michigan resident}$.

Independent variable

A variable that is typically manipulated to determine its effects on the dependent variable, consisting of at least two levels.

Dependent variable

The variable that is typically measured to examine its relationship with the independent variable and is hypothesized as related to or caused by changes in the independent variable.

Discrete (or categorical) variables

Variables that can only take on specific values with no other values existing between them; this includes nominal and ordinal variables.

Continuous variables

Variables that can take on a full range of values; this includes interval and ratio variables.

Reliability

A measure that is consistent, meaning it would find the same value if measured today and tomorrow.

Validity

A measure that accurately measures what it was intended to measure.

Hypothesis testing

The process of drawing conclusions about whether a particular relationship between variables is supported by the evidence.

Operational definitions

The specification of concrete procedures, called operations, used to measure or manipulate a variable.

Correlation

An association between two or more variables that measures pre-existing relationships without manipulation.

Experiment

A study in which participants are randomly-assigned to a condition, level, or group of one or more independent variables.

Random assignment

An experimental technique that provides every participant in a study an equal chance of being assigned to any of the groups or experimental conditions.

Between-groups research design

A research design where different people complete the tasks and comparisons are made between the groups.

Within-groups research design

Also known as a repeated-measures design, this involves the same participants doing things more than once, with comparisons made over time.

Replication crisis

A situation in psychology where a number of classic studies failed to replicate in subsequent research, often attributed to small samples or questionable research practices.

Data ethics

A set of principles related to all stages of the research process, from idea development through the communication of results.

Open science

An approach to research encouraging collaboration and the transparent sharing of research methodology, data, and statistical analyses.