We describe a new interactive annotation scheme between a human annotator who carries out simplified annotations on CFG trees, and a statistical parser that converts the human annotations automatically into a richly annotated HPSG treebank. In order to check the proposed scheme's effectiveness, we performed automatic pseudo-annotations that emulate the system's idealized behavior and measured the performance of the parser trained on those annotations. In addition, we implemented a prototype system and conducted manual annotation experiments on a small test set.