  In this paper, we consider the meta learning problem for estimating the
graphs associated with high-dimensional Ising models, using the method of
$\ell_1$-regularized logistic regression for neighborhood selection of each
node. Our goal is to use the information learned from the auxiliary tasks in
the learning of the novel task to reduce its sufficient sample complexity. To
this end, we propose a novel generative model as well as an improper estimation
method. In our setting, all the tasks are \emph{similar} in their \emph{random}
model parameters and supports. By pooling all the samples from the auxiliary
tasks to \emph{improperly} estimate a single parameter vector, we can recover
the true support union, assumed small in size, with a high probability with a
sufficient sample complexity of $\Omega(1) $ per task, for $K = \Omega(d^3 \log
p ) $ tasks of Ising models with $p$ nodes and a maximum neighborhood size $d$.
Then, with the support for the novel task restricted to the estimated support
union, we prove that consistent neighborhood selection for the novel task can
be obtained with a reduced sufficient sample complexity of $\Omega(d^3 \log
d)$.
