Number of observations (n)
What does n mean in statistics?
How many observations a dataset has, written n. Also called the sample size.
Count the rows of your dataset, leaving out the header row, and you have the number of observations. Statisticians write it as a lowercase n, and when the dataset is a sample, n is also called the sample size.
n is usually the first number to report about any dataset, because it tells your audience how much evidence sits behind everything else you say. A percentage built from 15 interviews deserves more caution than the same percentage built from 1,500.
From our own dataset
If you interviewed 18 people, your dataset has 18 observations: n = 18.
Where we teach it
Lesson 1.2 of Project 1: Sibling Interviews. Watch lesson 1.2 and read the notes, free with a free account.
Related terms
- Observation: A complete record of the characteristics we observed about one person or thing.
- Sample: The part of the population we actually observe.
- Number of variables (k): How many variables a dataset has, written k.
- Row: A horizontal line of cells.