Psychology · Year 11 · Research Methods · 5.º Período

Experimental Design and Hypotheses

Students learn how to formulate testable hypotheses and design psychological experiments. They will distinguish between independent, dependent, and extraneous variables.

TL;DR:Experimental design is the 'how-to' of psychology. Students learn to move from a general idea to a testable, operationalised hypothesis. They explore the different types of experiments (lab, field, natural) and the crucial role of variables, independent, dependent, and extraneous. This topic is the foundation of all psychological research and is heavily weighted in the AQA GCSE exams.

• National Curriculum Attainment Targets
• AQA GCSE Psychology 3.2.2.1 Formulation of testable hypotheses
• AQA GCSE Psychology 3.2.2.2 Types of variables

About This Topic

Experimental design is the 'how-to' of psychology. Students learn to move from a general idea to a testable, operationalised hypothesis. They explore the different types of experiments (lab, field, natural) and the crucial role of variables, independent, dependent, and extraneous. This topic is the foundation of all psychological research and is heavily weighted in the AQA GCSE exams.

For Year 11s, research methods can often feel dry or overly mathematical. However, it is the most 'active' part of the curriculum. By designing and running their own mini-experiments, students see why control is necessary and how easily a 'confounding variable' can ruin a study. This hands-on approach turns abstract rules into practical problem-solving skills.

Key Questions

1. What is a null hypothesis?
2. How do researchers control extraneous variables?
3. What are the strengths of a laboratory experiment?

Watch Out for These Misconceptions

Common Misconception

A hypothesis is just a 'guess'.

What to Teach Instead

In psychology, a hypothesis must be a precise, testable statement that predicts the relationship between variables. A 'hypothesis surgery' activity where students fix 'vague' guesses helps them learn to operationalise their terms.

Common Misconception

Extraneous variables always ruin an experiment.

What to Teach Instead

They only become a problem if they aren't controlled and turn into 'confounding' variables. Through peer-reviewing each other's designs, students learn that identifying and managing these variables is a standard part of good science.

Active Learning Ideas

Inquiry Circle

The Variable Hunt

Students are given a series of 'bad' experiment descriptions. In groups, they must identify the IV, DV, and at least three extraneous variables that could 'mess up' the results, then propose a way to control them.

35 min·Small Groups

Simulation Game

Lab vs. Field

The class conducts the same simple memory test twice: once in a strictly controlled 'lab' (silent classroom) and once in a 'field' (the noisy canteen). They then compare the results and discuss the trade-off between control and realism.

45 min·Whole Class

Think-Pair-Share

Hypothesis Drafting

Students are given a topic (e.g., 'Does music help you study?'). They must work in pairs to write a null hypothesis and a directional hypothesis, ensuring both are fully operationalised.

20 min·Pairs

Frequently Asked Questions

What is the difference between an IV and a DV?

The Independent Variable (IV) is the thing the researcher changes or manipulates. The Dependent Variable (DV) is the thing the researcher measures to see if the change in the IV had any effect.

What does it mean to 'operationalise' a variable?

Operationalising means defining exactly how a variable will be manipulated or measured. For example, instead of 'measuring memory', you would 'measure the number of words recalled from a list of 20'.

What is a null hypothesis?

A null hypothesis is a statement that predicts there will be no significant difference or relationship between the variables being studied. It is what researchers try to disprove.

How can active learning help students understand experimental design?

Research methods are best learned by 'doing'. When students have to actually control the noise level in a room or decide exactly how to measure 'happiness', they understand the challenges of experimental design far better than by just reading a list of definitions. This practical experience makes the AQA exam questions on 'designing a study' much less intimidating.