POSS Test - Online Practice for the EEI POSS Test

The EEI and investor-owned electric utility companies participated in the development of the POSS test battery, which can estimate the probability of success of candidates in a variety of power plant operator positions. The POSS test may be used in the selections process of candidates for operating jobs in fossil, nuclear, or hydro power plants: 

  • Plant level operator
  • Control room operators
  • Boiler operator
  • Turbine operator
  • Switchboard operator
  • Water treatment operator
  • Operator trainee

The POSS test is arranged in two different batteries with slight differences regarding the components of the test and time limits. The tests of the battery measure how a candidate performs compared with other candidates on several aptitudes/abilities. The aptitude tests assess cognitive abilities considered essential for success in power plant operator positions.

POSS Test Battery Format

The POSS test battery is administered over approximately two hours and consists of four sections:

  1. Reading Comprehension (36 questions/30 minutes)
    This test assesses one's ability to read and comprehend written materials generally found in power plant training manuals. The test taker is presented with five passages and several follow-up, multiple-choice questions. The test includes 36 questions and is to be completed within 30 minutes.
  2. Mechanical Concepts (44 questions/20 minutes)
    This test assesses one's ability to understand mechanical principles. It consists of 44 multiple-choice questions, each one containing a picture of a mechanical situation, and is allotted 20 minutes.
  3. Mathematical Usage (18 questions/7 minutes or 46 questions/17 minutes)
    There are two separate versions of the mathematical usage test:
    • Short version - assesses one’s ability to work with basic mathematical formula, based on the provided information. This test includes 18 multiple-choice questions and is to be completed within seven minutes.
    • Long version - assesses one’s ability to solve and manipulate mathematical relationships. This test is comprised of three sections, including formula conversion problems, algebra problems, and word problems. The test includes 46 multiple-choice questions and is to be completed within 17 minutes.
  4. Figural Reasoning (20 questions/10 minutes)
    This test assesses one's ability to identify patterns in order to problem solve. It consists 20 multiple-choice questions made up of three different item types – picture series, comparison, and progression, and is allotted 10 minutes. 

POSS Scoring

POSS tests are scored and converted into an Aptitude Index ranging from 0-15. One’s score on the Aptitude Index is a measure of his/her cognitive abilities pertinent in plant operations work. Those who achieve high scores presumably understand mechanical principles understand written materials including, including tables and graphs, able to grasp and apply mathematical relationships, and accurately and quickly notice details.

The Aptitude Index predicts the expected probability of overall plant operations success, as well as the likelihood of success or failure in plant operations positions. 

Companies Which Use POSS Testing


Company Position(s)
APS Operator Trainee

Online Preparation

Looking to achieve high scores? JobTestPrep's 2021 POSS PrepPack™ is comprised of full-length practice tests for each of the battery's sections. You get in-depth explanations necessary for success, scores, timed and non-timed training modes, all acting as your POSS study guide.

Other EEI Tests



EEI, their tests (POSS, MASS, CAST, TECH, SOPD, SASS), and other trademarks are the property of their respective trademark holders. None of the trademark holders are affiliated with JobTestPrep or this website.