A-Z Popular Blog Experiments Search »
Scientific Control

Related Topics
Primary Research

Qualitative Information

What is a Natural Experiment?

A natural experiment is a real world situation that resembles an experiment without any intervention or control by experimenters. The term is used for empirical studies based on variables and control groups that occur spontaneously. Natural experiments are rarely as well controlled as an experiment in a lab but allow for unique scale and scope of research. They also allow for research to be conducted in areas where experiments would be unethical. The following are illustrative examples.

Laws & Regulations

A state bans the sale of a food that is considered unhealthy leading to a dramatic decline in its consumption. Other states in the same country continue to sell the food item and resemble a control group.


A train accident spills a petrochemical into a lake. Nearby lakes are unaffected and resemble a control. This situation may be used to model the effect of pollutants on ecosystems and organisms.


Family situations such as identical twins separated at a young age. This may be compared to identical twins who grew up together.


Habits such as heavy smokers, moderate smokers, occasional smokers and nonsmokers who live in the same area and have similar living conditions with the exception of their tobacco exposure. Here tobacco usage can be viewed as an independent variable and health outcomes as dependent variables. Habits often don't exhibit random assignment. For example, heavy smokers may have things in common such as stress or a poor diet that impacts health.


Lifestyles such an urban neighborhood where people commonly walk to work, shopping and recreation such that most people in the area walk a considerable number of miles in a week. This might be compared to a suburban neighborhood in the same city where people drive everywhere such that they have remarkably low rates of walking activity.


The distribution of pollution such as poor air quality near a major highway or port with better air quality in other parts of the same city.

Social Inequality

Social inequality such as a pool of people who have no access to healthcare in an area where other people have access to high quality healthcare.

Social Equality

The introduction of new levels of social equality such as a nation that makes university tuition free.

Consumer Choice

Consumer choices such as subscriptions to media content. In the 1980s and early 1990s, before internet use was common, there was a sharp difference in media exposure based on cable TV subscriptions that were commonly sold in packages of channels. For example, teenagers who watched several hours of music videos a day versus those who had virtually no exposure or access to this media based on the cable subscriptions of their parents.


Historical events such as a country that is divided into two completely different political systems due to war and conflict.


Budget cuts that result in a sudden change to services in a region. For example, a school district that suddenly changes average class size to 40 students per teacher where neighboring school districts remain at 25 students per teacher.

Systemic Change

A complete change to a system. For example, the introduction of forest kindergartens in countries such as Denmark, Sweden and Germany whereby preschoolers have no classroom and learn in a natural setting filled with exploration, play and guided by a system of trust. This is based on a system of parental choice such that regular classroom instruction of preschoolers occurs in the same communities.


Cultural practices such as a period of fasting whereby a population severely restrict their diet for cultural or religious reasons.

Land Development

Human driven change to ecosystems such as a forest that is quickly converted to a large area of concrete facilities for a sports event. This might be used to model effects such as urban heat islands.

Economic Conditions

Economic conditions such as an economic collapse that causes people to substitute a variety of goods. For example, the consumption of more rice and less meat.
Overview: Natural Experiment
A real world situation that resembles an experiment without any intervention or control by experimenters.
Related Concepts


This is the complete list of articles we have written about experiments.
Alternative Hypothesis
Control Group
Dependent Variable
Empirical Evidence
Experiment Design
Experimental Error
Explanatory Power
Natural Experiment
Negative Control
Negative Correlation
Null Hypothesis
Original Research
Positive Control
Positive Correlation
Primary Research
Qualitative Info
Random Assignment
Random Error
Scientific Control
Scientific Fact
Soft Science
Systematic Error
If you enjoyed this page, please consider bookmarking Simplicable.


A guide to designing and conducting experiments.

Negative Control

The definition of negative control with examples.

Systematic Error

The definition of systematic error with examples.

Random Assignment

The common types of random assignment for experiments.


The common types of research.

Random Error

The definition of random error with examples.


An overview of precision with detailed examples.

Empirical Evidence

The definition of empirical evidence with examples.

Statistical Analysis

A list of basic statistical analysis techniques.


An overview of how to calculate quartiles with a full example.

Misuse of Statistics

Patterns of mistakes in statistics.


A definition of cohort with examples.

Positive Correlation

The definition of positive correlation with examples and comparisons.

Negative Correlation

The definition of negative correlation with examples.

Alternative Hypothesis

The definition of alternative hypothesis with examples.

Secondary Research

The definition of secondary research with examples.
The most popular articles on Simplicable in the past day.

New Articles

Recent posts or updates on Simplicable.
Site Map