Psychology for VCE Units 3 and 4, 8e learnON and PrintAbout This Resource vii Acknowledgements xiv Exam terminology 1 PSYCHOLOGY Key science skills and research methods 1 Key science skills and research methods in psychology 3 1. 1 Overview 4 1. 2 Aims, hypotheses and variables 7 1. 2. 1 Aims 7 1. 2. 2 Hypotheses 8 1. 2. 3 Variables 12 1. 3 Scientific investigation methodologies 22 1. 3. 1 Types of research methods 22 1. 3. 2 Population, sample and sampling 23 1. 3. 3 Sampling techniques 28 1. 4