Combined PISA dataset

An algorithm model needs a generalised and wide coverage dataset. A generalised dataset able to provide high-accuracy prediction result. Combined Student, School and Teacher dataset with adjustment to a balanced dataset, which is ready to train the model.算法模型需要具备泛化能力与广泛覆盖范围的数据集。此类泛化性数据集可提供高精度的预测结果。将学生、学校与教师三类数据集进行融合，并调整为均衡数据集，即可直接用于模型训练。