Field studies are not experiments. They don’t study a cause-and-effect relationship and they don’t manipulate an IV to see the effect that it has on a DV.
Rather they use a real life environment and a real life event and situation.
They tend to produce qualitative data but they can also produce quantitative data.
In ethnography the researcher gets involved in the whole setting being studied, using many different research methods – this is similar to carrying out an in-depth case study.
This therefore means that field studies are more valid and more holistic than a laboratory or field experiment because both the task and the environment are both more true to life.
However, they are not replicable which means that they cannot be tested for reliability. Their loose controls mean that there is no control of variables and there may not be very good focus or consistency. This can result in incomplete or incomparable information being gathered and also means that confounding variables can become extraneous variables.