rú guǒ / shù jù / biàn huà / quē fá / guī lǜ xìng / mó xíng / jiù / hěn nán / zuò chū / kě kào / yù cè如果数据变化缺乏规律性,模型就很难做出可靠预测。If changes in the data lack regularity, it will be difficult for the model to make reliable predictions.