lin-0152

11.8 What the experiments establish

The ten-node study uses six independently generated nonlinear DAGs (seeds 21–26), each with three injected latent-confounded visible pairs. The geometric screen is evaluated by candidate-arrow recall; a local Gaussian scorer, using the Bayesian information criterion (BIC), then selects parent sets inside that mask. The generator’s topological order is supplied to this final step, and the best row from a small fixed hyperparameter grid is reported for each seed. It is therefore a screen-and-parent-selection test, not an order-free identification result. The Sachs diagnostic uses 853 measurements of 11 proteins and a 17-arrow canonical reference graph; its ordered parent-set row likewise uses a reference order, while pooled greedy equivalence search (GES) is the order-free comparator.

Study

Geometry result

Downstream result

Boundary

Three-node chain

asymmetric response scores recover direction

exact visible chain

indirect scores remain positive

Nonlinear latent fork

dominant residual contracts when the missing coordinate is revealed

fork interpretation recovered in control

not a general latent test

Ten-node nonlinear DAGs

calibrated masks retain mean recall \(0.907\)

local BIC gives mean directed \(F_1=0.864\)

best row selected from a small fixed grid

Sachs signaling

44 of 110 arrows retained; 15 of 16 pooled-GES arrows preserved

ordered diagnostic precision \(0.889\), recall \(0.471\)

field correlation only \(0.587\) on average

Table 11.1 The strongest evidence supports calibrated geometric screening followed by a conventional causal learner.

Experiment: BRIDGE/SKFM nonlinear-DAG sweep

On the ten-node nonlinear random-DAG sweep, the selected graphs average 12.8 arrows, precision \(0.834\), recall \(0.907\), and directed \(F_1=0.864\). Direct SKFM extraction is less stable on these harder graphs even when the learned fields are accurate; the order-to-adjacency step is the principal bottleneck. This retained failure establishes the current division of labor: use geometry for high-recall compression and a score-based, latent-aware, or differentiable method for global selection.

Boundary

The Sachs study is a calibration frontier, not a solved biological discovery benchmark. The order-assisted parent-set diagnostic and the order-free GES comparisons answer different questions and must not be merged into one score.