Check out the this graph on a NYT economics blog: http://economix.blogs.nytimes.com/2013/05/07/shorter-hours-but-not-for-truckers-and-temps/
It shows that temporary help employees work an average of about 35.1 hours per week, more than the approximate average of 34.4 hours of all private sector employees. Data from the Bureau of Labor Statistics shows that temporary and contract workers are as likely to work full time as all nonfarm workers. "Full time" is not a good antonym for "temporary" when referring to standard employment arrangements. ASA has tested "permanent" in focus groups and public opinion polling. People get it--there is no such thing as a permanent job.