The following information was reported in the Globalforce MoodTracker employee engagement survey. For those employed by their company less than one year: 58% considered themselves highly engaged, among those who had been recognized in the last six months, 73% were highly engaged. For those with one to two years with their company, 47% of all participants were highly engaged, while 64% of those who had been recognized in the last six months were highly engaged. For those with their company three or more years, 58% were highly engaged, while 68% of those who had been recognized in the last six months, were highly engaged. What techniques would you use to examine the power of recognition on engagement?