A correlational study is an attempt to find a correlation, or statistical relationship, between variables, phenomena that change or vary among people or can be varied for purposes of research. Correlations are expressed in terms of direction (positive or negative) and magnitude (degree). Two variables that are related positively increase or decrease together....Two variables have a negative, or inverse, correltion if, as one increases, the other decreases.Here's another brain-suckingly boring quote ripped from context:
A research design is a plan for conducting a scientific investigation: what questions are to be answered, how participants are to be selected, how data are to be collected and interpreted, and how valid conclusions can be drawn. For of the basic designs used in developmental research are case studies, ethonographic studies, correlational studies, and experiments. Each design has advantages and drawbacks, and each is appropriate for certain kinds of research problems.