at haphazard
at intervals
at irregular intervals
at random
brokenly
by catches
by chance
by fits
by jerks
by snatches
capriciously
carelessly
chaotically
desultorily
disconnectedly
discontinuously
eccentrically
erratically
every which way
fitfully
flutteringly
haltingly
haphazardly
helter-skelter
higgledy-piggledy
hit or miss
impulsively
in snatches
in spots
inconsistently
inconstantly
indiscriminately
intermittently
irregularly
jerkily
lurchingly
nonuniformly
off and on
patchily
promiscuously
quakingly
quaveringly
quiveringly
randomly
roughly
saltatorily
shakily
shudderingly
sloppily
sporadically