Hypothesis

Explanations > Social Research > Initiation > Hypothesis

Definition | Primary hypothesis | Null hypothesis | See also

Hypotheses are are the heart of much social research. Here's some useful notes about them.

Definition

A hypothesis is a predictive statement.

A researcher starts with a hypothesis and determines whether it is true or false, and the conditions for truth or falsehood.

Where there are several hypotheses, they are often abbreviated with a capital 'H' and a subscript (often a number).

Primary hypothesis

The primary (or alternative) hypothesis (or just the first in a long list) is often written as H_1.

Experiments often seek to prove the primary hypothesis to be true and may be considered to have 'failed' if this is not achieved. In reality, an experiment succeeds when it correctly concludes that the primary hypothesis is true or false. It only fails when its conclusions are incorrect (or that a correct conclusion is incorrectly reached).

Null hypothesis

The null hypothesis (often written as H₀) is the opposite of the primary hypothesis in that it includes all other outcomes.

Note that if H₁ is that X happens, then H₀ includes both Y happens (which is other stuff) and that nothing happens. 'Not X' means any

For example if you hypothesize that feeding cats dog biscuits will make them purr more, then the null hypothesis would include both that feeding cat dog biscuits makes them purr less or feeding them dog biscuits does not change their purr rate.

Proving the null hypothesis false is an effective way of proving the primary hypothesis true and is an implementation of Karl Popper's falsification rule in his Hypothetico-deductive model.