Aim and hypothesis

What is an aim in research?

The aim is the researcher’s area of interest—what they are looking at (e.g. to investigate helping behaviour).

How does an aim differ from a hypothesis?

An aim is a general statement of what is being studied, whereas a hypothesis is a precise, testable statement.
An aim states what the researcher is interested in, while a hypothesis states what the researcher predicts will happen.

What is a hypothesis?

A hypothesis (plural hypotheses) is a precise, testable statement predicting the outcome of a study.
It usually proposes a relationship between:

• Independent Variable (IV): what the researcher changes

• Dependent Variable (DV): what the researcher measures

How are hypotheses written in research?

Hypotheses are written in two forms:

• Null hypothesis

• Alternative hypothesis (called the experimental hypothesis in experiments)
  Only one can be accepted, and the other must be rejected.

What is the alternative hypothesis?

The alternative hypothesis states that:

• There is a relationship between the two variables

• One variable affects the other

• Results are not due to chance

• Results are significant in supporting the theory

What is the null hypothesis?

The null hypothesis states that:

• There is no relationship between the variables

• One variable does not affect the other

• Results are due to chance

• Results are not significant in supporting the idea

What is a directional hypothesis?

A one-tailed directional hypothesis predicts the nature of the effect of the IV on the DV.

• Used when there is previous research

• Predicts a specific direction

Example:
Adults will correctly recall more words than children.

What is a non-directional hypothesis?

A two-tailed non-directional hypothesis predicts that the IV will affect the DV, but does not specify the direction.

• Used when there is no previous research

Example:
There will be a difference in how many numbers are correctly recalled by children and adults.

Can a hypothesis be proven correct?

No. An alternative hypothesis can only be:

• Supported or

• Rejected

It can never be proven, as there is always a possibility of future evidence that could refute it.

Why must we avoid saying a theory is “proven”?

Because this implies 100% certainty, and in research there is always a chance that new evidence may refute the theory.

What is the first step in writing a hypothesis?

Identify the key variables:

• Independent Variable (IV) → manipulated

• Dependent Variable (DV) → measured

What does it mean to operationalise variables?

To define variables in terms of how they are measured or manipulated.
These are called operationalised variables or operational definitions.

How do you decide between directional and non-directional hypotheses?

• Use directional if there is supporting research

• Use non-directional if findings are limited or ambiguous

What makes a good hypothesis?

A good hypothesis is:

• Short (concise)

• Written in clear and simple language

• Testable

• Includes operationalised variables