4 clinical catergories from the nursing research book methods of critical appraisal need help what is it.?

my aunt is taking an online class she went out of town and she cant find her book does any one know what the four critical catergories are and if there is an online book i can look into. her work is do tonite thankyou all.

Sorry, I know this is probably too late, but I didn't see your question till now...

Critical appraisal is the technique used in Evidence Based Nursing (EBN) that facilitates the effectiveness of research by allowing the user to quickly exclude papers that are of too poor a quality to inform practice and to systematically evaluate those that are of merit. In a Evidence-based Nursing practice, the nurse must:

Clearly identify the issue or problem based on accurate analysis of current nursing knowledge and practice;
Search the literature for relevant research;
Evaluate the research evidence using established criteria regarding scientific merit; and
Choose interventions and justify the selection with the most valid evidence.

I know it's too late to assist your aunt, but hopefully it might help down the road.