目的：本研究以生態手段之直接知覺觀點，探討個體知覺與其行動的配連，並找尋不同年齡族群於判斷隙越距離與實際隙越距離之差異與預測因子。方法：實驗參與者為21名兒童、18名成人與19名老年人，經測量身高、眼高、腿長、腿部肌力與髖關節柔軟度後，進行隙越距離判斷測驗與實際隙越測驗，缺隙寬度為50公分至130公分。以3（年齡）×2（隙越情境）混合設計二因子變異數分析檢驗不同年齡組與隙越距離之關係，並以逐步迴歸檢驗隙越距離是否與個體之因子有正相關。結果：（一）兒童族群與老年人族群之判斷隙越結果與實際隙越結果差距相較於成年人有顯著差異，兒童與老年人的判斷與實際隙越結果差異均較成年人大。（二）髖關節柔軟度和三族群實際隙越之結果呈顯著正相關，另外老年人之判斷隙越距離和眼高及腿長亦呈顯著正相關，實際隙越距離和判斷隙越距離以及腿部肌力也呈現顯著正相關。結論：（一）相較於成人，隙越動作的知覺－行動配連準確度在兒童與老年人時期較低。（二）髖關節柔軟度是兒童、成人以及老年人實際隙越距離之預測因子；眼高、腿長以及髖關節柔軟度亦是老年人判斷隙越距離之預測因子；判斷隙越距離以及腿部肌力也是老年人實際隙越距離之預測因子。

Purpose: Direct perception perspective of ecological approach was used to investigate the coupling of individuals' perception and action, and to find out the different predictors of judging and actual crossing in different age groups. Methods: Twenty-one children, eighteen adults and nineteen old people joined in this experiment. The body height, eye-height, leg length, leg strength, and the range of motion in hip were measured before the judged and actual gap crossing test. The length of gap was 50-130 cm. A3 (age)×2 (crossing) mixed design two-way ANOVA was used to examine the relationship between age groups and crossing tests, and a stepwise regression was used to test the correlation between crossing and individual factors. Results: (1) There is a significant difference between judged and actual crossing in children and old people than adults, and (2) The range of motion in hip is positively correlated to actual crossing in these three groups. The eye height and leg length were also positively correlated to old peoples' judged gap crossing; the perceptual result and the leg strength were also positively correlated to actual gap crossing. Conclusions: (1) Children and old people have lower perception-action coupling ability than adults, and (2) The range of motion in hip can be the predictor of actual crossing in each age group. The eye height, leg length and range of motion in hip can also be the predictors of judged crossing for old people. Judged crossing result and leg strength were the predictors of actual crossing in old people.