A-Z Popular Blog Hypothesis Search »
Negative Correlation

Positive Correlation

Research Design

14 Examples of a Null Hypothesis

A null hypothesis is a prediction that there is no relationship between variables. This is an important assumption for scientific inquiry as it requires any relationships between independent and dependent variables to be proven as opposed to assumed. The following are illustrative examples of a null hypothesis.
Rain doesn't influence people's self-reported mood.
The behavior of catfish isn't correlated to earthquakes.
Taking a medication will not influence the outcome of a disease.
Coffee intake doesn't correlate with higher worker productivity.
Green walls don't influence human behavior.
The price of bananas isn't correlated to the price of tomatoes.
Social media use isn't correlated with self-reported happiness.
Airplane age isn't correlated to accident rate.
Film genre isn't correlated to average ratings from film critics.
Watering isn't associated with plant growth.
Average hourly hours spent reading isn't associated with vocabulary skills.
Air quality isn't correlated with self-reported quality of life.
Salt content isn't correlated to choice of salad dressing in a taste test.
The water content in the regolith of the moon isn't influenced by exposure to sunlight such as areas of the surface that are permanently shadowed.

Null Hypothesis vs Alternative Hypothesis

An alternative hypothesis is any hypothesis that isn't the null hypothesis. This includes predictions of positive correlation, negative correlation or causation.

Null Hypothesis vs Research Hypothesis

A research hypothesis is a prediction that indicates the purpose of inquiry. For example, research that predicts that a medication will have some benefit. The research hypothesis can be the null hypothesis or it can be an alternative hypothesis.


The statements above aren't statements of fact. As with all hypotheses, the null hypothesis isn't necessarily true. It is simply a base assumption that can be disproven with evidence.
A common mistake with null hypotheses is to state that there is no relationship between variables in a single direction. For example, "air temperature doesn't increase appetite." This isn't a null hypothesis as it leaves open the possibility that air temperature decreases appetite. A correct null hypothesis is "air temperature and appetite aren't correlated" or "air temperature doesn't influence appetite."
Overview: Null Hypothesis
A prediction that there is no correlation between variables.
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.


The definition of hypothesis with examples.

Hypothesis Types

The common types of hypothesis 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.

Science Vocabulary

An a-z list of important words in science with straightforward definitions.

Science Words

An a-z list of foundational science vocabulary.

Research Design

An overview of the common types of research design.


A guide to designing and conducting experiments.


A list of the branches of physics.

Hard Science

A list of the hard sciences.

Soft Science

The definition of soft science with a list of its basic characteristics.

Words To Describe Science

A vocabulary for describing science, research and scientific knowledge.

Experiment Design

Full examples of an experiment design using a useful template.
The most popular articles on Simplicable in the past day.

New Articles

Recent posts or updates on Simplicable.
Site Map