formal or informal: Formal research is controlled, objective, and systematic gathering of data. The researcher carefully defines the things under study and what will and won't be studied. It is systematic in that we carefully follow prescribed rules in gathering and assessing data. It is controlled in that we carefully define, gather, and evaluate the data according to prescribed rules that can be reviewed for error. The formal method provides a description based upon agreed upon units that can be measured and assessed for reliability, whereas the informal method describes the data based on the intuition of the researcher. (page 6 of Don Sacks's book, "Primer of Public Relations Research.")