Congress prohibited the use of all relevant mechanical or electrical devices, including polygraph, deceptograph, voice stress analyzer, or psychological stress evaluator; paper and pencil tests were not included. Local, State, and Federal government employers are exempted from the EPPA, as are security services, employers involved in the drug industry, and employers conducting ongoing investigations of economic loss or injury. The law prohibits the use of the polygraph results as the sole basis of an adverse employment decision and restrains the employer from disclosing the information obtained in most cases. The polygraph examination includes data collection, pre-test interview, test administration, and post-test interview. Although proponents of lie detector tests accept two fundamental assumptions -- that there is a relationship between lying and certain emotional states and a relationship between those emotional states and physical changes in the body -- other studies reveal a ten percent chance of error due to several factors. Discriminatory effects may exist based on sex and ethnic background or physical or mental handicaps due to different physiological reactions among ethnic groups or biases of the examiner. The EPPA was opposed by private industry, especially those components most concerned with internal theft and other security risks. The Department of Justice opposed the legislation as an example of federalism. The American Polygraph Association advocated establishing strict standards for the training and testing of polygraph examiners. Employers have begun exploring alternatives including increased background and reference checks, new technologies such as pre-recorded telephone interviews, and the paper and pencil test.