Overt Participant Observation Previous Page Recording Data
The fact the researcher is involved with the group they are studying in an open way means it is relatively easy to generate and record data (especially in comparison with covert participant observation where the fact of being in the group secretly would make the group suspicious if you openly recorded conversations...). 

With overt participant observation the researcher is, for example, able to record conversations, ask questions, take notes and the like with the knowledge and co-operation of the people involved.

Although group members are aware of the researcher, these things should, with time, become an almost natural, imperceptible, aspect of group interaction and, consequently, will not change the way the group members behave...