The degree of directed care required from nurses who work at the critical care unit environment was assessed and compared through three different psychophysical methods: magnitude estimation, category rating and ordinal scales. The sample was formed by 29 participants whose ages varied from 25 to 44 years. Based on the results, authors concluded that: a) data indicated a high concordance among participants regarding different situations with a Kendall's coefficient of 0.83 (p < 0.0016); b) the results obtained with magnitude estimation scaling proved superiority of this method when compared to others. c) the continuum of directed attention (non metric) has characteristics of a protetic continuum.83108114