Correlational research investigates the connection between two or more variables that are already present in a group. The aim is to identify if changes in one variable result in changes in another. There are three types: positive correlation where increases in one variable produce increases in another; negative correlation where increases in one produce decreases in another; and no correlation where the variables are independent. Common data collection methods include naturalistic observation, archival data, and surveys. Correlational research is non-experimental, backward-looking, and dynamic as relationships can change over time. The correlation coefficient indicates the strength and direction of relationships between variables.