Brent Cook of Exploration Insights was certainly in demand at this year's PDAC conference in Toronto, but Resource Investing News was able to snag a few minutes with him to chat about his thoughts on the gold space and what to look for in a gold company. When asked about the biggest mistake investors make when doing their due diligence on a company, Cook suggested that some rely on hope, or view the space too much as a "treasure hunt," rather than objectively assessing a company's performance."There's a lot of science behind it," he said. "You've got to evaluate the results coming in against the thesis you had when you bought the stock."He also stated that the way a company presents itself, in terms of its website, press releases, etc., is very important. In that vein, he spoke about a drill hole interval calculation tool that he's helped put together, and about why properly interpreting drill results is key for investors.Finally, in terms of companies he's keeping an eye on, Cook mentioned Mirasol Resources (TSXV:MRZ) and London listed Mariana Resources (LSE:MARL) as two stocks that he owns and is watching right now.