What is the difference between a parameter and a statistic?

In the world of data, where numbers reign supreme, understanding the difference between a parameter and a statistic is crucial. Here's the key difference:

Parameter:

  • Represents a characteristic of the entire population you're interested in.
  • It's a fixed, unknown value you're trying to estimate.
  • Think of it as the true mean, proportion, or other measure of the entire population (like the average height of all humans).
  • It's usually denoted by Greek letters (e.g., mu for population mean, sigma for population standard deviation).

Statistic:

  • Represents a characteristic of a sample drawn from the population.
  • It's a calculated value based on the data you actually have.
  • Think of it as an estimate of the true parameter based on a smaller group (like the average height of your classmates).
  • It's usually denoted by Roman letters (e.g., x-bar for sample mean, s for sample standard deviation).

Here's an analogy:

  • Imagine you want to know the average weight of all elephants on Earth (parameter). You can't weigh every elephant, so you take a sample of 100 elephants and calculate their average weight (statistic). This statistic estimates the true average weight, but it might not be exactly the same due to sampling variability.

Here are some additional key points:

  • You can never directly measure a parameter, but you can estimate it using statistics.
  • The more representative your sample is of the population, the more likely your statistic is to be close to the true parameter.
  • Different statistics can be used to estimate different parameters.
Related content or attachment:
What is the nominal measurement level?
What is the ordinal measurement level?
What is the interval measurement level?
What is the ratio measurement level?
Startmagazine: Introduction to Statistics

Startmagazine: Introduction to Statistics

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Introduction to Statistics: in short

  • Statistics comprises the arithmetic procedures to organize, sum up and interpret information. By means of statistics you can note information in a compact manner.
  • The aim of statistics is twofold: 1) organizing and summing up of information, in order to publish research results and 2) answering research questions, which are formed by the researcher beforehand.
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