As the backbone of all science, the scientific method is a systematic approach to generating new knowledge by collecting data to answer a research question.

Data are the currency of science, each data point a recording of a measurement on some scale, each point representing one value of a variable that uses that scale. This module explains how psychologists define and use variables and how we measure the values of those variables when we collect data.

Different research questions and variables call for different research designs. This module describes the four basic research designs, how they work, and the kinds of data they yield.

Conclusions in science are always tentative—new evidence may force us to reconsider them, or a once valid-seeming proposition can be rendered invalid on a reconsideration of existing evidence. this module considers different forms of validity and how they are evaluated.

This module provides a variety of information and tools from the American Psychological Association (APA) that will help inspire you as you complete your coursework and plan your career goals. Explore APA resources on various psychological issues and scholarly research and writing; a list of sites providing valuable resources on diversity, equity, and inclusion in psychology education and in the professional community; resources on a career in psychology; and links to career opportunities at the APA.