Tech giant Amazon has abandoned an artificial intelligence (AI) tool it had been building for three years after determining that the system was discriminating against women, reports Reuters.

The AI tool, intended to help with recruitment by trawling for candidates online, reportedly downgraded résumés containing the word "women's" and filtered out potential hires who had attended two women-only colleges, noted Business Insider. 

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“Everyone wanted this holy grail,” one source told Reuters. "They literally wanted it to be an engine where I'm going to give you 100 résumés, it will spit out the top five, and we'll hire those." 

The AI tool was built using past résumés submitted to Amazon over a 10-year period as a reference point for hiring, Business Insider reported. Because these résumés were predominantly submitted by male applicants, the tool perpetuated this pattern and developed a bias against female hires, presuming male candidates were preferable.

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While engineers attempted to tweak the system, glitches remained and executives lost faith in pursuing the project by early 2017, according to the Reuters report.

The case study sets a dismal precedent for other companies hoping to harness similar technology in the near future. According to a 2017 survey by talent software firm CareerBuilder, approximately 55% of US human resources managers said AI would be a regular part of their work within the next five years. 

“How to ensure that the algorithm is fair, how to make sure the algorithm is really interpretable and explainable — that’s still quite far off,” said Nihar Shah, a computer scientist who teaches machine learning at Carnegie Mellon University, in an interview with Reuters.

John Jersin, vice president of LinkedIn Talent Solutions, also told Reuters that he didn’t see the service as a replacement for traditional recruiters.

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“I certainly would not trust any AI system today to make a hiring decision on its own,” he said. “The technology is just not ready yet.”

Amazon is reportedly now testing a new version of the automated employment screening, focused on diversity.