Posted by: Ed Tittel
always check the survey method when analyzing survey results, ruminations on the 2012 Global Knowledge IT Skills and Salary survey
To keep up with what I sometimes call the “cert biz” I read LOTS of blogs and newsletters. So when the latest Global Knowledge newsletter hit my inbox last Thursday (2/23/2012) I perked up a bit to see the following story headline “15 Top Paying IT Certifications for 2012.”
My initial interpretation of this story’s headline led me to expect that the highest-paying certs would be included in this round-up. And in fact some of those credentials are indeed present in their list — most notably the PMP (Project Management Professional) and the CISSP (Certified Information Systems Security Professional) certs.
The report cited in the story comes from Global Knowledge’s own “annual IT Skills and Salary survey.” That story also includes the following prefatory remark as its second paragraph:
Note: The rankings below are based on certifications that received the minimum 200 responses required to derive a salary figure that is statically accurate. There are certifications that pay more that are not represented due to their exclusive nature. These include CCIE: Cisco Certified Internetworking Expert and VCDX: VMware Certified Design Expert, for example.
Hmmm. I assume “statically” is a mistake, and probably should read “statistically.” Interesting that Randy Muller, the story’s author, does not provide the overall sample size and its statistical characteristics, nor does he explain how he arrived at the 200 number necessary to achieve statistical significance. I understand where he’s coming from — namely, “the Law or Large Numbers” which essentially states that “…as the number of samples increases, the average of these samples is likely to reach the mean of the whole population” (source: Investopedia). The idea is you have to have some number of responses before averaging them bears any relationship to reality.
Nevertheless, the Note quoted above does recognize that there are other “…certifications that pay more that are not represented due to their exclusive nature.” That means “for which 200 responses were not received” as I take it. To his mention of CCIE and VCDX, I would also add the Cisco Certified Architect, the various SAP R/3 credentials, Microsoft’s Certified Master (MCM) and Certified Architect (MCA) — and lots of other architect-level certifications in general — plus such niche credentials as the Wireshark Certified Network Analyst, the GIAC Security Expert (GSE), and so on and so forth.
The survey reports on 15 top-paying certs, not THE Top 15 certs by pay. Big difference, and important to keep in mind when deciding whether or not to follow the fairly sizable herd of responses (15 certs times a minimum of 200 for each one indicates a sample size larger than the 3,000 respondents required to include them, not accounting for individuals who hold 2 or more of those credentials) being tracked and analyzed.