A list with elements:
$null_model: Vector with the model name and number of free parameters
$alt_model: Vector with the model name and number of free parameters
$lr: likelihood ratio test statistic 2 * (-log(L1) - -log(L2))
$df: degrees of freedom (difference in number of parameters between models)
$p_val: probability of rejecting null model in favor of alternative
model due to chance (e.g, if <0.05, data favors alternative model).