Introduction to Statistics: Fundamentals, Data Types, and Sampling Methods

Vocabulary flashcards covering core concepts from Chapters 1.1, 1.2, and 1.3, including critical thinking, types of data, levels of measurement, sampling techniques, and study designs.

Statistical Significance

A condition achieved when the likelihood of obtaining the observed results by chance is very small.

Practical Significance

A condition where a finding or treatment effect is large enough to make a meaningful difference in practice.

Loaded Question

A survey question that is intentionally phrased or worded to elicit a desired response.

Voluntary Response Sample

A sample in which the respondents themselves decide whether or not to be included, creating a high potential for bias.

Correlation Does Not Imply Causation

The principle that an association or statistical correlation between two variables does not prove that one variable causes the other.

Quantitative Data

Numerical data representing counts or measurements.

Qualitative Data (Categorical Data)

Data consisting of names, labels, or qualities that do not represent numerical counts or measurements.

Discrete Data

Quantitative data that can take on only specific countable values, typically represented by whole numbers.

Continuous Data

Quantitative data resulting from measurements that can take any value within a given continuous interval.

Population

The complete collection of all individuals, items, or scores being studied.

Sample

A subcollection or subset of members selected from a population.

Parameter

A numerical measurement that describes a characteristic of an entire population.

Statistic

A numerical measurement that describes a characteristic of a sample.

Nominal Level of Measurement

A measurement level consisting of categories, labels, or names only, which cannot be arranged in an ordering or ranking scheme.

Ordinal Level of Measurement

A measurement level where data can be arranged in some order or rank, but differences between data values are meaningless or cannot be calculated.

Interval Level of Measurement

A measurement level with ordered data and meaningful differences between values, but with no natural or absolute zero starting point.

Ratio Level of Measurement

A measurement level with ordered data, meaningful differences between values, and an inherent natural zero point where ratios are meaningful.

Simple Random Sample

A sample selected in such a way that every possible sample of the same size $n$ has the exact same chance of being selected.

Systematic Sampling

A sampling method where a starting point is selected and every $k\text{th}$ member of the population is chosen.

Convenience Sampling

A sampling technique that relies on selecting subjects that are easiest to reach or access.

Stratified Sampling

A sampling method where the population is divided into distinct subgroups sharing characteristics, and a sample is drawn from each subgroup ("some from all").

Cluster Sampling

A sampling method where the population is divided into sections, several sections are randomly chosen, and all members in those chosen sections are studied ("all from some").

Observational Study

A study in which researchers observe and measure specific characteristics of subjects without attempting to modify them or apply any treatment.

Experiment

A study in which researchers apply a treatment to subjects and then proceed to observe and measure the effects on those subjects.

Retrospective Study

An observational study that collects data by looking backward in time at past events or existing records.

Cross-Sectional Study

An observational study in which data are observed, measured, and collected at one specific point in time as a snapshot.

Prospective Study

An observational study that follows a group of subjects forward in time to collect future data as events unfold.