Finding the right candidate for the job can be a challenge. Sometimes, it can feel as though you are looking for a needle in a haystack -- and inevitably, the decision needs to be made quickly.

When the interviewing process drags on, work is left incomplete, other employees are stressed and overextended, hiring managers are impatient, and top talent begins flying off the shelf. But this is not a decision that you want to make out of haste. Getting it wrong can be not only extremely expensive, but also a drain on your whole organization -- especially if you hire a toxic employee

If left unchecked, a toxic employee can bring a whole team down. In a study conducted by Will Felps, Terence R. Mitchell, and Eliza Byington, "How, When, and Why Bad Apples Spoil the Barrel: Negative Group Members and Dysfunctional Groups," they found that a single negative employee can cause a 30 to 40 percent drop in a team's performance. 

It's no wonder why Google, in an effort to avoid toxic hires, would subject candidates to a grueling 12-interview process. 

A article revealed that Google receives more than two million job applications each year. Based on the ratio of applicants to hires, landing a job at Google is roughly 10 times more difficult than getting into Harvard.

While putting these candidates through the ringer might have made Google feel better about its hiring decisions, the exhausting process didn't help its already overworked employees or its candidate experience.

To ensure that this amount of interviewing was necessary, Google's People Analytics Team examined five years of interviewing data and feedback. Specifically, they wanted to know how many interviews it would take to predict whether or not a candidate would receive an offer.

Hit fast forward, and Google found that after four interviews, the statistical likelihood that an additional interview would improve a candidate's chances of getting an offer dropped. In other words, "four interviews were enough to predict whether someone should be hired at Google with 86 percent confidence." For every extra interview, the law of diminishing returns set in.

This research, in addition to a couple of other experiments, led Google to implement the "Rule of Four." This change resulted in a two-week reduction in the average time-to-hire, saved Google employees thousands of hours in interviewing time, and helped reduce the already tedious process for candidates. 

Let's explore the significance of these results further. 

Reducing time-to-hire.

Time-to-hire is calculated by taking the total days positions are open and dividing them by the number of positions filled.

For every extra day a position goes unfilled, your organization is spending unnecessary money on recruiting fees, marketing/advertising costs, and on resources (consultants, technology, or other employees) -- not to mention the opportunity cost. 

When you have as many open positions as Google, it adds up. 

Freeing up employees.

Interviewing is a considerable time commitment. It takes a lot of effort to prepare, participate, and provide feedback. That's valuable time employees could be spending elsewhere. 

As one of the only non-renewable resources, time is something that every organization needs to be respectful of, especially since those on your interviewing panels are more than likely your organizations top performers. 

Improving the candidate experience.

Candidate experience is a term used to describe the impressions applicants have of your organization during and after the hiring process. A positive candidate experience can boost employee engagement, strengthen your employer brand, and increase your organization's ability to compete for top talent. 

In Google's case, think about the time candidates had to take to coordinate travel, get time off of work, be away from their families, and prepare for 12 interviews -- it's a little excessive. This shift to the Rule of Four will help Google complement its great brand with an efficient hiring process.

With advances in screening technology and access to research like Google's, the days of excessive interviewing processes are hopefully behind us -- and that's good for everyone.