<PAGE>
EXHIBIT 11(A)
VIALOG CORPORATION
CALCULATION OF SHARES USED IN DETERMINING NET LOSS PER SHARE
(Unaudited)
<TABLE>
<CAPTION>
Three Months Ended Six Months Ended
June 30, June 30,
-------------------- --------------------
1999 2000 1999 2000
--------- --------- --------- ---------
<S> <C> <C> <C> <C>
Common stock, beginning of
period........................... 8,399,066 9,137,854 3,693,672 9,133,569
Weighted average common shares
issued during period, net........ 163,183 235,372 3,446,474 137,559
Common stock options and warrants
using the treasury stock method.. -- -- -- --
--------- --------- --------- ---------
8,562,249 9,373,226 7,140,146 9,271,128
========= ========= ========= =========
Net loss (in thousands)........... $ (5,208) $ (1,087) $ (6,925) $ (2,278)
========= ========= ========= =========
Basic and diluted net loss per
share............................ $ (0.61) $ (0.12) $ (0.97) $ (0.25)
========= ========= ========= =========
</TABLE>
20
