In some instances there may be a genuine partnership between researcher and others. The distinction between researcher and others may disappear. On other occasions the researcher may choose for whatever reason to maintain a separate role. Participation may be limited to being involved as an informant. The participants, too, may choose something less than full partnership for themselves under some circumstances.
Most action research is qualitative.
Some is a mix of qualitative and quantitative. All else being equal, numbers do offer advantages. In field settings, though, one often has to make other sacrifices to be able to use them. Most importantly, sometimes numbers are not easily applied to some features of a study. If these include features of particular interest or importance, the choice is between qualitative research or omitting important features.