Issue link: https://resources.twc.edu/i/1233486
33 Copyright © 2017 Gallup, Inc. All rights reserved. Methodology Results for The Washington Center (TWC) study are based on web surveys conducted June 26–July 27, 2017, with a sample of 1,817 TWC alumni. The sample of alumni email addresses was provided by TWC. Alumni were included in the study if the institution had an email address on le. Results for the Gallup-Purdue Index, the national study used for comparison purposes, are based on web surveys conducted Feb. 4, 2014–Oct. 11, 2016, with a random sample of 4,429 respondents with a bachelor's degree or higher, aged 18 and older, with internet access, living in all 50 U.S. states and the District of Columbia. The Gallup-Purdue Index sample was recruited via the Gallup Daily tracking survey. The Gallup Daily tracking survey sample includes national adults with a minimum quota of 60% cellphone respondents and 40% landline respondents, with additional minimum quotas by time zone within region. Landline and cellular telephone numbers are selected using RDD methods. Landline respondents are chosen at random within each household on the basis of which member had the most recent birthday. Gallup Daily tracking respondents with a college degree, who agreed to future contact, were invited to take the Gallup-Purdue Index survey online. Gallup-Purdue Index interviews are conducted via the web, in English only. Samples are weighted to correct for unequal selection probability and nonresponse. The data are weighted to match national demographics of gender, age, race, Hispanic ethnicity, education and region. Demographic weighting targets are based on the most recent Current Population Survey gures for the aged 18 and older U.S. bachelor's degree or higher population. All reported margins of sampling error for the Gallup-Purdue Index of all college graduates include the computed design effects for weighting. • For results based on the total sample of those with a bachelor's degree, the margin of sampling error is ±2.1 percentage points at the 95% condence level. • For results based on employee engagement of those with a bachelor's degree, the margin of sampling error is ±2.3 percentage points at the 95% condence level. • For results based on those with a bachelor's degree from public institutions, the margin of sampling error is ±2.8 percentage points at the 95% condence level. • For results based on employee engagement of those with a bachelor's degree from public institutions, the margin of sampling error is ±3.0 percentage points at the 95% condence level. • For results based on those with a bachelor's degree from private institutions, the margin of sampling error is ±3.6 percentage points at the 95% condence level. • For results based on employee engagement of those with a bachelor's degree from private institutions, the margin of sampling error is ±3.0 percentage points at the 95% condence level.