Chapter 2 research methods: tools for discovery. Theories must produce predictions that can be tested with empirical research. Research starts with ideas from theory, previous research, or observations. A general idea has to be translated into a clear research hypothesis. Before collecting empirical data, looking at past work is important. Operationalization defining a concept so that it is observable and measurable; translating ideas into accessible forms. Make decisions about research designs, methods, samples, and analyses. Laboratory experiments: primary way researchers investigate causal connections. Field experiments, interventions, and natural experiments: used to avoid artificiality and other problems associated with labs, field experiments. An experiment where changes in real-world settings are deliberately created and the outcome of the manipulation is measured. Observer bias an observer"s tendency to be influenced by knowledge about the research design or hypothesis. In field experiments, the results can be more easily generalized to real life.