One hundred forty-three nurses served as their own controls in planning care for hypothetical patients under three different manipulated conditions of decision support: (A) use of traditional resources; (B) use of a printout of a computerized protocol for care planning (NPC); and (C) use of an NPC protocol and a self study guide. A series of 3 x 5 repeated measures analyses of variance (ANOVAs) were used to evaluate the main effects and interactions of the experimental treatment conditions and the two nurse attribute variables of education and experience (each with five levels). The case problems and conditions were counterbalanced to control for extraneous variables. The repeated measures ANOVA demonstrated significantly higher mean ratings of quality for care planned under both computerized decision support conditions than the traditional condition on all three patient problem situations F(2, 270) = 7.9, p less than .01. Time on task was also significant F(2, 272) = 5.8, p less than .01 with use of the decision support consultants tending to increase time in planning.