This is good advice, and the first comments don't do this helpful article justice. I have just been reading about reference checks in standard reference books about hiring (as part of updating my differing FAQ about hiring procedures before I post it to my personal website), so I can vouch for the correctness and helpfulness of what is said in the submitted article. The procedures mentioned are legal, and you are a chump if you don't use them.

Recycling some electrons, here is an adaptation of a comment I made on Hacker News about a year ago:

There is an art to checking references. Even if a company has a policy of giving bare minimum information, find out a TELEPHONE NUMBER of someone in that company who knows your candidate and start a conversation. I was given a specific script of questions to ask back in the 1990s when I was a community volunteer for my local public school district, doing reference checks on superintendent candidates. A consultant advised the school district (and through the district, me) on how to do this. If you talk to someone directly by voice, and have a good list of specific questions to ask about the candidate, you will be AMAZED at what people say, policy or no policy. Company policies don't keep people from sharing stories with curious listeners. The key is to learn what questions are legal to ask and reveal the most interesting stories about the person you are thinking of hiring. There are consultants who can advise you about checking references, and, as people who have had actual hiring authority for important jobs will say, checking references is a lot less expensive than making a wrong hiring decision. Once you've learned the questions, you know what to ask.

I've just asked my consultant Google, and he suggests several sets of useful questions to ask when checking references:

http://hiring.monster.com/hr/hr-best-practices/recruiting-hi...

http://www.drgnyc.com/list_serve/Jan24_2005.htm

http://www.acadweb.wwu.edu/hr/Employment/InfoForHiringOffici...

http://www.best-job-interview.com/reference-check-questions....

http://www.k-state.edu/hr/employment/referencecheck.htm

http://pbsbo.ucsc.edu/personnel_payroll/staff/recruit/ref_ch...

http://www.bridgespan.org/Publications-and-Tools/Hiring-Nonp...

http://jobsearch.about.com/od/referencesrecommendations/a/re...

AFTER EDIT: My comment on the initial response to this comment of mine is that I am on record

https://news.ycombinator.com/item?id=5227923

as saying here on HN that if you want to hire a good worker, you should give the job applicant a work-sample test. Research tells us that, and wishful thinking can't make that untrue.

But if you are relying on anything said implicitly by someone's references to decide whom to hire, you had better check the references. People lie on their reference lists. They do that a lot in industries where the custom is not to check references. (We have read some stories about that here on HN over the years.) If your work-sample procedure for hiring is airtight enough, checking references may not add much to your hiring procedure, but it is legally safer to check references (to avoid employer legal exposure for negligent hiring) than to not check references. You prove you are a gentleman and a good sport by letting the honest people be discovered as honest when you check their references. Engaging in wishful thinking on this issue protects you neither legally nor practically.