Statistical Analysis with Software Application - Chapters 1 & 2 Vocabulary

Statistics (Plural Sense)

Numerical facts or summaries, such as an average salary, a company's monthly sales growth rate, or the percentage of invoices collected on time.

Statistics (Singular Sense)

A field of study concerned with collecting, organizing, presenting, analyzing, and interpreting data so that useful conclusions can be made.

Statistics (Working Definition)

The science of learning from data, providing methods for turning raw observations into information that can support description, comparison, prediction, and decision-making.

Descriptive Statistics

The area of statistics that describes the data actually observed using tools such as tables, charts, mean, median, percentage, and standard deviation.

Inferential Statistics

The area of statistics that uses sample evidence to make conclusions about a larger population using tools such as confidence intervals, hypothesis tests, regression, and ANOVA.

Population

The complete collection of individuals, items, transactions, or observations of interest.

Sample

A subset selected from the population for analysis.

Parameter

A numerical value or characteristic describing a population.

Statistic

A numerical value or characteristic calculated from a sample.

Variable

A characteristic that can take different values across different observations.

Observation

One unit, case, or record for which values are recorded in a dataset.

Dataset

An organized collection of observations and variables.

Qualitative / Categorical Data

Data whose values represent qualities, labels, or categories, such as account type, payment status, audit opinion, or department.

Quantitative / Numerical Data

Data whose values represent counts or measured amounts for which arithmetic operations are meaningful, such as sales amount, number of invoices, collection days, or inventory cost.

Discrete Variable

A quantitative variable that takes countable values, often whole numbers, answering the typical question 'How many?'

Continuous Variable

A quantitative variable that can take any value within a meaningful interval, subject to measurement precision, answering 'How much?' or 'How long?'

Cross-Sectional Data

Data collected from many units at approximately the same point in time.

Time-Series Data

Data that follow one variable or unit across multiple time periods.

Panel Data

Data that combine cross-sectional and time-series dimensions by observing multiple units across multiple time periods (also called longitudinal data).

Statistical Thinking

Approaching a problem by asking what data are needed, how the data were generated, how much variability is present, what sources of bias may exist, and how strong the evidence is.

Primary Data

Data collected directly and first-hand for a specific current study.

Secondary Data

Already existing data that were originally collected for another purpose and are reused for the present analysis.

Dependent Variable

The outcome variable being studied in an analytical question that an analyst tries to explain, predict, or measure.

Independent Variable

An explanatory or predictor variable in an analytical question used to evaluate its effect or relationship on the dependent variable.

Nominal Level of Measurement

A measurement level where values identify categories with no inherent ranking, equal intervals, or true zero.

Ordinal Level of Measurement

A measurement level where categories have a meaningful order, but distances between categories are not assumed to be equal.

Interval Level of Measurement

A measurement level where numerical values have equal intervals, but zero is arbitrary rather than a true absence of the quantity.

Ratio Level of Measurement

A measurement level where numerical values have equal intervals and a meaningful true zero, allowing meaningful ratio comparisons.

Data Dictionary

A documented repository or table containing variable names, descriptions, types/levels, allowed values or coding schemes, units of measurement, and treatment of missing values.

Missing Value

A condition that occurs when a value that could have been recorded is unavailable due to nonresponse, entry omission, unavailable records, system errors, or non-applicability.

Collection_Days

A variable measuring a completed payment cycle, which is known only after payment occurs.

Days_Outstanding

A variable measuring how long an unpaid receivable has remained unpaid as of a reference date.

Survey Method

A data-collection method where respondents answer standardized questions; efficient for measuring attitudes, preferences, and self-reported behavior.

Interview Method

A data-collection method where a researcher asks questions directly, allowing clarification and deeper responses.

Observation Method

A data-collection method where a researcher records events or behavior as they occur.

Experiment Method

A data-collection method where a researcher manipulates a factor under controlled conditions to