Abundant research shows that a good corporate culture is correlated with better financial performance, more innovation, and greater customer satisfaction; whereas a toxic corporate culture can sink a company. But culture has historically been difficult to define and measure, forcing managers to rely on anecdotes and personal observations to understand their organization's culture.

MIT Sloan Management Review and Glassdoor have unveiled the Culture 500, an online interactive tool that evaluates and ranks the corporate cultures of more than 500 of the most powerful companies in the United States. The rankings are based on the "Big 9" dimensions of culture (collaboration, integrity, agility, diversity, customer orientation, execution, innovation, performance, and respect).

To develop the Culture 500 tool, Donald Sull, an MIT Sloan School of Management senior lecturer and co-founder of CultureX, and his team analyzed the free-text responses from 1.2 million Glassdoor reviews of current and former employees. Researchers used a natural language processing method that classifies text into more than 90 culture-related topics. The process combined insights from subject area experts with machine learning tools to build a dictionary of more than 20,000 terms that indicates which aspect of culture an employee was discussing. Each company assessment is based on the percentage of employees who discuss one of the Big 9 values (incidence) and how favorably they assess it (sentiment).

The Culture 500 offers a snapshot of culture within a company; users can view graphs with a horizontal axis that shows how frequently employees mentioned a specific value and a vertical axis that shows how positively they talked about that value—all compared with the other Big 9 values, as well as graphic comparisons to competitors.