Social psychologists have developed several theories for explaining the ways in which the psychology of a crowd differs from and interacts with that of the individuals within it. Major theorists in crowd psychology include Gustave Le Bon, Gabriel Tarde, Sigmund Freud, and Steve Reicher.
KPIs, or key performance indicators, are measures too. But generally, KPIs are the most important measures for a business or organisation, usually having the highest leverage to impact its success. Due to their catchy name, the term KPI has almost become synonymous with the term performance measure.
KPIs, or key performance indicators help organizations achieve organizational goals through the definition and measurement of progress. The key indicators are agreed upon by an organization and are indicators which can be measured that will reflect success factors. The KPIs selected must reflect the organization's goals, they must be key to its success, and they must be measurable. Key performance indicators usually are long-term considerations for an organization.