The pilers were more chaotic and let papers pile up.

而堆垛机则更加混乱，文件堆积如山。

The researchers involved took a close look at the paper-processing strategies of two types of office workers they labeled as " filers" and " pilers."

参与调查的研究人员仔细观察了两类办公室工作人员的纸张处理策略，分别称之为“文件归档人”和“堆垛机”。