Most support DEI, but don't know how to implement it. Read our report on diversity, equity & inclusion in the workplace

Lost lessons from the invention of the interview

Among Thomas Alva Edison’s lesser known inventions was the modern job interview. The wizard of the original Menlo Park (New Jersey, not California) whose prodigious spree of invention and entrepreneurship helped shape the early 20th century and the American economy, developed his own pre-employment test. Edison, a self-taught genius whose most important inventions from the stock ticker and the electric light bulb to the phonograph had been developed with only a handful of assistants, had a distrust of callow college graduates that would be immediately recognizable to today’s digital titans.

At the turn of the last century, the once lowly telegraph operator, who attended school for only 12 weeks of his life, had risen to be head of his own wholly-owned electrical utility. And yet his toughest challenge was technical recruiting and he had grown disillusioned with the mathematicians and scientists who applied to Edison Lighting (these days known as General Electric).

The interview as ordeal

His response was the creation of a pre-employment test that the autodidact and polymath felt reflected the breadth of knowledge missing in the candidates he encountered. The resulting “Edison test” quickly became a thing of legend.

In 1921 the New York Times revealed details of the test in a breathless splash headlined “Edison questions stir up a storm”. The paper of record reported that “victims” of the test had complained they would need to be walking encyclopedias to have passed.

The candidates’ complaints are strikingly similar to those that have been made against firms with exacting hiring processes such as Google. One failed candidate beseeched Edison to remember that college graduates were people with interests other than “the depth of the ocean”, while another hurt and bombastic complainant invoked Socrates’ warning: “belief that because he knows one thing well he knows all things well.”

The Times published 141 questions that it claimed were remembered by a single candidate who had sat the test. The range of knowledge they demanded remains startling, from the whereabouts of the Sargasso Sea and the River Volga, to who invented the algorithm and how leather is tanned.

The test was alternately feted and denounced — usually depending on how the reviewer had scored. For those determined to measure themselves against the great man, adapted versions of the test exist online today.

Berating the bone-heads

Clearly not everyone enjoyed it. A candidate for production engineer who was invited to sit the exam described his experience: “During this time Mr Edison paced back and forth, irritably demanding why certain results were not being obtained in his factory and denouncing what he termed bone-headed moves on the part of his executives, while the latter shouted their excuses into his deaf ears.”

The would-be engineer was then told by Edison himself that he had failed and “given the air” — a lost euphemism for being asked to leave.

Of course, the Edison test controversy wasn’t the invention of the interview so much as the emergence of the aptitude test. But it was, arguably, the birth of interview as ordeal. Four years earlier the United States military had deployed the Woodworth Psychoneurotic Inventory: 116 yes or no questions, now remembered as the first personality test.

The true origins of the interview have been jokingly traced by Lucy Kellaway to the New Testament, where Jesus, at the time recruiting disciples, leaned heavily on a single question: “What do you seek?”

The hundred years war

Nearly a century on from news of the Edison test, interviewers have a bewildering amount of research to turn to in preparing to question job candidates. Intelligence Quotient tests, once in vogue, have since been largely discredited as guides to future employee performance. General aptitude tests remain in wide use.

Today’s most popular interview questions can be boiled down into a handful of categories:

Technical questions evaluate a candidate’s ability to do the job. To fill a software engineering position it might mean a whiteboard coding test.

• Behavioral questions assume past behavior will be a predictor of future performance: “What were the steps you took to accomplish such and such task?”

• Situational questions tend to be hypothetical (the ones politicians refuse to answer), such as what would you do if the work of a teammate was not up to expectations?

Case questions, or brainteasers, were popular with Google and would have pleased Edison, as they aim to tease out how someone would work and think through a particular case: “how many traffic lights are there in LA?”

An arms race with potential employees

Despite this arsenal of approaches there’s continuing disquiet with the effectiveness of interviews. With each reinvention of the interview, candidates and their coaches catch up and overwhelm the innovators. It’s an arms race of sorts with potential employees.

Google’s Larry Page is said to have grown so bored of rehearsed answers that took to asking candidates to teach him something he didn’t already know how to do. Naturally, plenty of people copied him, so job seekers often arrive for interview these days with their lesson for the CEO pre-cooked.

At the core of this is our suspicion that our interviews are little more than subjective fits of confirmation bias — seeing what we want to see based on a shallow initial impression. This is also referred to as the “halo effect”.

Daniel Kahneman, the behavioral economist and Nobel laureate, conducted an experiment with Israeli army recruits that he later recalled in Thinking Fast and Slow. He replaced the battery of psychometric tests that had been used to assess soldiers’ readiness for combat with a strictly structured series of factual questions. The interviewers were to be given no license whatsoever and would handover the answers to be scored according to Kahneman’s predictive system.

Curious about structured interviews? Download our free guide to learn more.

The value of intuition

The sum of his six ratings system was to lift the interviews from “completely useless” to “moderately useful”. But in the face of a rebellion from disempowered interviewers he allowed them to add one element. They were to close their eyes and imagine the recruit as a soldier and score them from one to five.

To his surprise the “close your eyes” test delivered results comparable to the six ratings test. In other words intuition has a place in interviews. Kahneman’s verdict gives this advice: “do not simply trust intuitive judgement… but do not dismiss it, either.”

The obsolescence of job interviews is by now routinely predicted. Machine learning and big data, we’re told, will remove human error from the selection of candidates. In the meantime, a mixed approach and an awareness of our flaws can help us stumble in the direction of objectivity.

With the benefit of considerable hindsight it would be easy to dismiss the interview techniques of the irascible Edison. They appear to say more about his contempt for conventional education and perceived privilege than anything else. But before doing so it’s worth noting the identities of some of those whom he did hire, they include Henry Ford, Nikola Tesla and the pioneer of early flight William Joseph Hammer.

It’s also worth remembering some who failed. Albert Einstein paid a visit to Boston during the original furore over the Edison test and was confronted by a cheeky reporter with one of the inventor’s questions on the speed of sound. He didn’t know the answer.

Stay in the loop!

Sign up for jargon-free hiring resources.

Let's grow together

Workable helps companies of all sizes hire at scale. Start today by
requesting a demo or posting a job for free to discover how Workable
can help you find and hire great people.

Get started