About

The MASS test is one of seven EEI tests. It was developed to serve as an employment selection test in the plant maintenance field. More than 40 electric utility companies took part in a four-year study to develop the test. The study was directed by the Personnel Decisions Research Institute of Minneapolis, Minnesota and began in 1981. Job and cost/savings analyses and performance ratings were included in the research. Based on this research, the MASS test is able to estimate the probability of a candidate's success in the following categories related to plant maintenance jobs:

  • Mechanic, machinist, electrician, welder, pipefitter, steel worker, rigger
  • Instrument and control repairer
  • Helper, painter, insulation worker

The MASS test is similar in design, scope and administration to the POSS test. It may also be used when selecting candidates for power plant maintenance positions in fossil, nuclear, and hydro plants. Explore our other EEI tests.


MASS Test Battery

The MASS test battery is administered over approximately two hours. It consists of four tests (or sections):

  1. 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 an illustration of a mechanical situation. This test is allotted 20 minutes.
  2. Spatial Ability/Assembly (20 questions/10 minutes)
    This test assesses one's ability to visualize the properly assembled form of an object. A diagram featuring parts of an object is presented, each part labeled with a letter. Candidates are required to assemble the parts so that ones with corresponding letters are put together. The test consists of 20 multiple-choice questions and has a 10-minute time limit.
  3. Mathematical Usage (18 questions/7 minutes)
    This test assesses one's ability to work out basic mathematical problems using the information provided at the beginning of the test. The test includes 18 multiple-choice questions and must to be completed within seven minutes.
  4. 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 must to be completed within 30 minutes.

MASS Scoring

The scores from the four MASS aptitude tests are combined into a Cognitive Index Score. This score allows for potential employers to predict the probability of a successful job performance. 


Prepare Online for MASS

Even small improvements in your score can determine whether or not your potential employer will be impressed. JobTestPrep's MASS practice pack contains practice materials for all MASS test sections, with in-depth answer explanations, that act as a MASS test study guide. Learn more about our state of the art MASS practice tests by practicing now.

To access any of the other EEI test pages, click on the test abbreviation:


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.


What's Included

  • 3 full-length, MASS Mechanical Concepts tests  
  • 3 full-length MASS Mathematical Usage tests
  • 2 full-length MASS Reading Comprehension tests
  • 2 full-length MASS Assembly tests
  • Additional practice units, tutorials and solving tips 
  • Including all question types seen on the real test
  • All tests include answers and explanations
  • Secured payment
Related PrepPacks™ that come with membership: