The research glossary defines terms used in conducting social science and policy research, for example those describing methods, measurements, statistical procedures, and other aspects of research; the child care glossary defines terms used to describe aspects of child care and early education practice and policy.
Cross-Sectional Data
Coverage reflects the extent to which all elements on a sampling frame (list) are members of the population to be sampled, and the extent to which every element in that population appears on the frame (list) once and only once. For example, the extent to which a list of child care providers includes (covers) all the providers in a given location (state, community).
Cross-Tabulation
A method to display the relationship between two categorical variables. A table is created with the values of one variable across the top and the values of the second variable down the side. The number of observations that correspond to each cell of the table are indicated in each of the table cells.
Crossover Design
A crossover design (also called switch over or change over design) is a type of experimental design in which each research subject receives a sequence of experimental treatments over a number of time periods. A major advantage of the crossover design is that each subject serves as his or her own control. They often require a smaller number of participants than more traditional Randomized Control Trial designs.
Curvilinear
A statistical relationship between two variables that is not linear when plotted on a graph, but rather forms a curve.