Within the software engineering field, researchers have investigated whether it is pos- sible and useful to summarize software artifacts, in order to provide developers with concise representations of the content of the original artifacts. As an initial step to- wards automatic summarization of source code, we conducted an empirical study where a group of Java developers provided manually written summaries for a variety of source code elements. Such summaries were analyzed and used to evaluate some summarization techniques based on Text Retrieval.
 This paper describes what are the main features of the summaries written by developers, what kind of information should be (ideally) included in automatically generated sum- maries, and the internal quality of the summaries generated by some automatic methods.