This document discusses quantitative research designs and their validity. It explains that research designs provide information on how and when data will be collected. The best design depends on the research question. For example, to measure the effects of an intervention, researchers might take pre-test and post-test measurements. Some designs are better than others at controlling for threats to internal validity, which is the accuracy of measurement. Students are asked to explore threats to internal validity and identify the design that best controls for all threats.