The comparison of nursing competence pre- and postimplementing clinical ladder system.

Samples were selected at two different times. At first sampling, populations were from staff nurses who were just classified as N1, N2, N3 and N4 level according to the clinical ladder system. Samples were randomly selected from N1 and N2, N3 level subjects and N4 subjects were all selected as samples. Sample sizes were 416, and 321 questionnaires returned were usable. At second sampling, populations were from all the N1, N2, N3 and N4 level staff nurses in that time period. Samples were randomly selected according to the ratio N1:N2:N3:N4 (4:8:2:1). Sample sizes were 360, there were 222 returned usable questionnaires.