  We present a flexible model to describe the effects of generic deviations of
observed gravitational wave signals from modeled waveforms in the LIGO and
Virgo gravitational wave detectors. With the detection of 11 gravitational wave
events from the GWTC-1 catalog, we are able to constrain possible deviations
from our modeled waveforms. In this paper we present our coherent spline model
that describes the deviations, then choose to validate our model on an example
phenomenological and astrophysically motivated departure in waveforms based on
extreme spontaneous scalarization. We find that the model is capable of
recovering the simulated deviations. By performing model comparisons we observe
that the spline model effectively describes the simulated departures better
than a normal compact binary coalescence (CBC) model. We analyze the entire
GWTC-1 catalog of events with our model and compare it to a normal CBC model,
finding that there are no significant departures from the modeled template
gravitational waveforms used.
