CLS Research Methods & Evidence-Based Practice 3

Question 1

Which type of study design allows a CLS to infer causation rather than mere correlation between a lubrication change and equipment outcome?

Accepted Answer

Controlled prospective experiment

Answer

Controlled prospective experiments with randomization and controls are the gold standard for establishing causal relationships.

Question 2

A facility switches lubricants and bearing failures decrease. What additional evidence is needed before attributing the improvement to the lubricant change?

Accepted Answer

Ruling out confounding variables such as maintenance practice changes or operating condition shifts

Answer

Confounding variables must be ruled out before attributing an observed improvement to a specific change in lubrication.

Question 3

In lubrication research literature, what does 'p < 0.05' signify?

Accepted Answer

There is less than a 5% probability the results occurred by chance

Answer

A p-value below 0.05 means there is less than a 5% probability that the observed difference is due to random variation.

Question 4

Which organization publishes the most widely cited standardized test methods for evaluating lubricant performance properties?

Accepted Answer

ASTM International

Answer

ASTM International publishes the most widely used standardized test procedures for lubricant properties used globally.

Question 5

What is the primary limitation of using 'time-in-service' as the sole criterion for oil change intervals?

Accepted Answer

It ignores actual lubricant condition, which can vary with load, temperature, and contamination

Answer

Time-based intervals do not account for real-world variation in lubricant degradation rates driven by operating conditions and contamination.

(CLS) Certified Lubrication Specialist Practice Test

(CLS) Certified Lubrication Specialist Practice Test

CLS Research Methods & Evidence-Based Practice 3