22 Apr What Is a Hypothesis? Definition, Examples, and Types.

What Is a Hypothesis?

 

A hypothesis is a research-based prediction
of an outcome involving at least two variables in an experiment or test. For a
prediction to be considered a hypothesis, it must be testable. In other words,
you need to be able to manipulate the two variables to prove your prediction.
It must also be falsifiable. This means there is more than one possible
outcome, and a chance that your prediction will be proved false.

 

Part of a Hypothesis

 

A hypothesis has three components,
which are also requirements for it to be considered a hypothesis: 

 

A.      Independent variable: The independent
variable is the one that is expected to cause a change at the end of the
experiment.

B.      Dependent variable: The dependent
variable is the one that is expected to be changed by the independent variable
at the end of the experiment.

C.      Reasoning based on research: The
reasoning part of the hypothesis should include an explanation, based on facts
and research.

 

Using these components, a
hypothesis follows the “If A, then B, because C” format, where “A” is the
cause, “B” is the effect, and “C” is the reason. The following
“fill-in-the-blank” structure may help you to better understand the segments of
a hypothesis:

 

If _______ (state “A” how it will react with “B”), then _______ (state
“B” and how it will change), because __________(provide “C”).

 

How to Write a Hypothesis

 

To write your hypothesis, follow
these basic steps:

 

1)     
Determine what elements (independent and
dependent variables) you would like to include in your experiment.

2)     
Ask a question about what would happen if these
variables were to interact.

3)     
Use your prior knowledge of the variables, and
conduct research to form an educated prediction of what the outcome will be.

4)     
Develop your hypothesis, which should include an
answer to the question you asked in step 2.

 

Hypothesis Examples

 

Here is an example of a scientific
experiment, along with a hypothesis about it:

 

You have about 2 cups of
strawberries to be stored in a mason jar. You also have a mixture of water and
distilled vinegar to wash the berries with. You want to determine if the water
+ vinegar mixture will preserve the better for longer than water alone.

 

·        
Independent
variable: Distilled vinegar

·        
Dependent
variable: Strawberries

·        
Reasoning:
Prior knowledge of distilled vinegar acting as a preservative, trials, etc.

 

So the question is: Does washing
strawberries in distilled vinegar and water keep them fresh for longer than
soaking them in water alone? After conducting some research and testing both
solutions (one with vinegar and one without), you hypothesize that:

 

If you rinse strawberries
soak them in a water/distilled vinegar mixture for 10 minutes, then the
strawberries will be preserved for three more days than if you didn’t use
vinegar, because of the vinegar’s preserving acetic acid content.

 

Remember, a hypothesis must be
falsifiable. Therefore, it should be possible that the vinegar will not keep
the strawberries fresh for longer than water alone.

 

Types of Hypotheses

 

Some of the most common types of
hypothesis include:

 

·        
Simple: Combines
only independent variable and one dependent variable

·        
Complex: Involves
at least two dependent variables and at least two independent variables

·        
Directional: Predicts a
positive or negative relationship between the dependent and independent
variable

·        
Non-directional: Predicts
a relationship between two variables without specifying if it’s positive or
negative

·        
Null: Proposes that one variable has
little or no effect on the other  

·        
Alternative: Claims
that a null hypothesis is false

 

 

Scientific Hypothesis vs. Research Hypothesis

The variables involved in a
standard classroom or laboratory science experiment typically involve a solid,
liquid, or gas. Such an experiment might involve a food and a chemical.
However, in psychology and other forms of research, a hypothesis can also
involve a much longer list of variables. This list includes people, specific
settings, actions, situations, etc. For example, you may want to determine if a
person will respond differently to a certain stimulus if they are first exposed
to the responses of others.