I don't remember exactly how long I studied but I think it was around 2 weeks. Economics comes pretty naturally to me, so I was able to pass with a 70 using only InstantCert. I went through all the information 3 times. The second time through I took detailed notes; the third time was in random order. Then I took the sample test in the Official Study Guide in order to get a feel for how I would do with some "fresh questions".

If you are worried, I would recommend taking the Peterson's sample tests Search for Colleges and Universities, Graduate Schools, Online Degree, Private Schools - Peterson's. I did not use them for Macro, but they were immensely helpful when I was studying for Biology and Educational Psychology (topics which do not come as easily to me). The Peterson's tests I used were really good. They will either give you more knowledge or more confidence. Neither one hurts

Chris
93 credits!
Recently took: Edu Psych CLEP (67) 10/1/07, MIS DSST (66) 10/1/07, Statistics DSST (78) 10/2/07
Next up: Ethics: Theory & Practice ECE 11/7/07 and Organizational Behavior ECE 11/8/07