descriptive statistics

Descriptive Statistics

The branch of statistics concerned with summarizing, organizing, and describing a dataset — mean, median, mode, standard deviation, percentiles, frequency distributions.

When you'd see it: Any data summary report. 'The average customer spends $42 per order with a standard deviation of $18' is descriptive statistics. Descriptive statistics describe what happened in the data you have — they make no claims about populations or causation.

Why it matters: Descriptive statistics is the foundation of data literacy — understanding what summary numbers mean, when to use mean vs median, how to read a distribution, and what outliers imply. Most business reporting is descriptive, even when it's presented as if it's causal.

Common mistakes: Presenting descriptive statistics as if they imply causation or generalize beyond the observed dataset. 'Customers who use feature X have 40% higher retention' is a descriptive finding — it may be explained entirely by selection bias.

Related mean, median, standard deviation, variance, inferential statistics