Plant Operator Selection System Test

Who Must Take the POSS Exam?

Applicants for technical or supervisory positions at utility companies are required to take the Plant Operator Selection System (POSS) test. Passing POSS at the level desired by plant management is a condition, but not a guarantee, of employment. Developed by the Edison Energy Institute (EEI) for use by nuclear, hydropower, or fossil fuel companies, POSS is an 80-minute, multiple choice, pencil -and -paper assessment of the cognitive skills needed for competent performance in such jobs as operators of turbines, boilers, or control rooms. Power plants administer POSS according to EEI standards with no calculators or dictionaries permitted. Test takers with special needs may contact the employer before testing concerning to make the appropriate arrangements.

POSS Organization and Administration

The POSS includes five test batteries: Reading Comprehension, Mathematical Usage, Tables and Graphs, Mechanical Concepts, and Figural Reasoning. Strict time limits govern each section of the test. The applicant’s ability to move swiftly to respond to the questions she or he is most likely to answer correctly is crucial to success on the POSS.

The Reading Comprehension section consists of five paragraphs about scientific or technical topics typical of those found in utility training materials. Following the readings are 36 questions to be answered in 30 minutes. The Mathematical Usage test requires applicants to convert feet to meters, ounces to grams, and similar standard measures, and then to select the correct answer based on their calculations. To aid test takers, the POSS includes tables of basic measurements, such as feet to acres and gallons to liters.

POSS offers two versions of the Mathematical Usage test. Applicants for operator positions take the shorter version with 18 questions to be completed in 7 minutes. The questions in the shorter test require computations based on mathematical formulas. Applicants for supervisory jobs take the longer form of the Mathematical Usage battery, focused on problem-solving skills. There are three types of questions in the longer test: formula conversions, algebra problems, and word problems, for a total of with 46 questions to be completed within 17 minutes. The longer version of the Mathematical Usage section increases the total number of questions on the POSS to 230, compared to 202 questions on the shorter test.

The Tables and Graphs portion of the POSS consists of two parts: Tables (with 60 questions to answer in 5 minutes) and Graphs (with 24 questions and a time limit of 4 minutes). Tables exhibit numerical relationships, such as water temperature to convector length, requiring test-takers to select, for example, the correct heating output per hour in BTU’s. Graphs may include information such as a comparison of the square feet covered by various types of paint finishes. Test takers must interpret the data presented in tabular form and choose the correct answer from the available options.

The Mechanical Concepts section gives applicants 20 minutes to answer 44 questions. This section tests an applicant’s ability to use mechanical devices in the workplace. Line drawings of such devices as levers, pulleys, gears, fulcrums, or ramps, precede operational questions concerning spin, speed, momentum, pressure, or direction of motion.

The Figural Reasoning portion of the POSS (also called the Spatial Ability test) poses 20 questions to be completed in 10 minutes. Each question begins with a drawing of a disassembled device with every part identified by a letter. Next, five drawings appear from different perspectives. Lines point to the location of hidden parts of the assembly. The test taker must visualize the assembled device and then select the best representation of it.

Plant Operator Selection System Study Guide

POSS Evaluation

Employers derive test scores ranging from 0 to 15 according to EEI’s Aptitude Index, which measures the applicant’s intellectual abilities and mechanical talent. The plants that administer the test establish their hiring standards, so there is no common “passing score” for the POSS test. Employers do not release the score required for the available positions, and EEI does not reveal whether guessing on the POSS improves or lowers test scores.

POSS Test Preparation

Veteran test takers agree that time management is crucial to POSS success. Time restrictions and challenging material can keep applicants from the positions they desire. Practice is essential to a positive POSS result.

The Mometrix Plant Operator Selection System SECRETS Study Guide readies test takers to achieve on the POSS. Applicants learn how to decode the wording of test questions to eliminate unlikely answers and how to guess intelligently between possible responses. The exercises in the POSS SECRETS Study Guide simulate actual test batteries. Technically accurate and easy-to-understand, the SECRETS Study Guide offers clear explanations of mechanical concepts and provides detailed instructions for manipulating three-dimensional figures. Test takers learn to glean relevant data from reading selections, word problems, tables, and graphs. Thorough test preparation with the Mometrix SECRETS Study Guide can transform POSS into a pass.

POSS Test Study Guide

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Last Updated: 07/14/2018

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