Treating bibliometric indicators with caution: their dependence on the source database

No~vrrrlrrys, with conzputer-supported rrnrrlysis of rlrrtrrbnses, constructing biblionretric or scientonteiric inrlicrrtors nrny be consirlered errsy. Theprobleni is nzore to serify the nccurrrcy of tire globnl anrrlysis, including the sany~ling of drrtrr. The global coherence of rm analysis depends on tlte nrlequrrcy of rrll the steps. Using on-line drrtnbrrses, nn experinlent ~vrrs rlesigned to denwnstrrrte this. Keeping the sang protocol for dnta collec.tion, the srrnte inrlicrrtors rrre user1 oser the ~lrrrious mzples. he resultsfronr three sepnrnfe rlrrtrrbrrses are profounrlly rZi&ferent.