The field of psychology has an aim that, on the surface, appears straightforward: to understand human behaviour. However, human behaviour is varied and complex, and achieving this goal presents a considerable challenge. Researchers must be familiar with and adhere to regulatory requirements to ensure that research is consistent with ethical principles. The breadth of questions that psychology attempts to answer demands researchers are able to employ a wide array of research methods and design principles. The variety of data collected in psychological research, and the purposes for which data is collected, requires that researchers make informed choices from a range of data analysis tools. Researchers must also make decisions about the format and style of presentation for summarising and reporting conceptual and numerical information for a variety of audiences. In this unit you will examine research methods that will help you design studies to investigate questions about relationships and differences among psychologically relevant variables. You will learn when and how to use data analysis methods to summarise data, test statistical hypotheses and interpret the results for relationships and differences among variables. You will learn about the principles that underlie ethical research, in relation to both research participants and the conduct of researchers themselves. The skills and knowledge developed in this unit will provide you with the necessary tools to critically evaluate research from the major sub-disciplines of psychology, as well as a wide-range of other science-based disciplines.