In the simplest form, and up until about 10-12 years ago, paper and pencil was the only method available. Now, there are event recorders, but they come with their limitations, namely cost and accessibility. The features of an event recorder can quickly be divided into those that you might consider necessary, those you consider desirable, and those you consider unimportant. Maria has evaluated a number of event recorders and has the following preferences for the work she does. The observer can record more rapidly-occurring streams of behavior and use more categories than are practical with paper and pencil methods.
Computers eliminate the transcription and entering of data on paper into computers.
Large quantities of data can be stored in much smaller spaces. Automatic computation of inter-observer reliabilities are possible. Output files are directly importable into standard statistical and spreadsheet packages. Some event recorders limit your flexibility. Computers produce a barrier between the observer and the data.