Typically, conference proceedings have much smaller impact factors (IF) than journal papers. Very often their IFs are in the range of 0.2 to 2. Can somebody tell me why it is the case?
Most people do not quote from conference proceedings. The reasons:
a) Almost everyone also publishes the same thing in a journal (usually beforehand)
b) The peer-reviewing standards in proceedings are non-existant to rudimentary.
Impact factor is directly derived from how many people quote. Since almost all research can be also found in a peer-reviewed journal, it bolsters the authors case to use those instead, since they directly build on evidence from someone else. So to avoid questions, you directly quote the research article and not the proceedings.
A lot of the arguments are of similar nature as what Yurgos wrote above.
I submitted a paper into IET_CDS journal, one of the reviewers commented that each conference paper I quote should be replaced by a journal paper if possible.
This is because journal papers have more credibility than conference papers due to the more proper review process in journals than conferences.
As a result of what happened to me ( and happen to everyone), journal papers get more citations which means more impact factors.