餐食的旦現有時候是單個大的放在一個盒子裡，有時是數個小的擺在盒中一起販售O前人研究多半僅單向地探討大的物體在知覺上容易被低估，或數個小的容易有高估的現象O很少研究是雙向地來比對，從而發現會產生低估或高估的反向偏誤，並且偏誤有時是不對稱的O本研究利用二個主實驗來探討這類現象O實驗結果發現，大物體和小物體分別會造成低估和高估的反向偏誤O在單一物體比較單一物體時，不同大小比例之間其知覺重量並沒有顯著差異O但是，在分散物體比較分散物體時，里現不對稱的反向偏誤，在更分散的小物體之間知覺重量有顯著的差異O

Sometimes, food packaged in a box for sale is displayed in single product;
however, sometimes it packaged with a lot of small products in the box. Previous research has been done for many years on investigating a single, big object perceived smaller than their actual size or dispersion objects overestimated than their actual weight. However, less research has been done on comparing these verestimated or underestimated biases by reversal directions, and discovering they were asymmetric, sometimes. Thisresearch is divided into two studies and the experimental methods were used. The results showed that the big objects were underestimated and the smaller objects were overestimated, respectively. In single-single comparing test, the different sizes of the objects were not significant.
Contrarily, in the dispersion-dispersion comparing test, the reversal bias was not symmetric. Only the more dispersive and smaller objects had significantly different perceptual weight.