Exam blueprint

EqasOnline Certified Proficiency Testing Professional

This page tells you what the exam covers, how it is built and how to prepare.

The credential shows that you passed an exam on the knowledge a person needs to take part in proficiency testing (PT) and act on the results. It is not an accreditation. It is not a certification of persons under ISO/IEC 17024. It is not connected to, or endorsed by, any accreditation body.

Exam format

The Candidate handbook explains the rules, retakes, results and appeals.

Domains

Every exam follows this table. Each candidate gets a different mix of questions, but the number from each domain is always the same.

D1. PT fundamentals and requirements (6 questions)

• What proficiency testing is, and how it differs from internal quality control.
• The difference between an interlaboratory comparison, proficiency testing and external quality assessment (EQA).
• Which standards and policies expect laboratories to take part in PT or EQA, and which standards cover PT providers and PT statistics. You need to know what each covers, not its text.
• Fair participation: testing PT items the routine way, following the provider's instructions, not sending items to another laboratory, and not discussing results with other participants before the closing date.

D2. Designing and running a round (6 questions)

• What a scheme plan sets out.
• Why PT items are checked for homogeneity and stability, and what each check shows.
• Dispatch, closing dates and keeping participant results confidential.
• How a provider evaluates results and reports them.

D3. Assigned value, σpt and Algorithm A (8 questions)

• The two values behind every score: the assigned value (xpt) and the standard deviation for proficiency assessment (σpt).
• The ways a provider can set the assigned value, from formulation and certified reference values to a robust consensus of participants, and when each suits.
• How Algorithm A limits the effect of outlying results, step by step.
• The ways a provider can set σpt, and why a value fixed in advance keeps scores comparable between rounds.
• The uncertainty of the assigned value, when it is small enough to ignore, and what to do when it is not.

D4. Performance scores (8 questions)

• Calculating a z score, and the satisfactory, questionable and unsatisfactory bands.
• Why about 1 in 20 good results scores as questionable by chance.
• Scores that include uncertainty: z′, ζ (zeta) and En, and when each is used.
• How qualitative results, such as detected or not detected, are scored.

D5. Reports and trends (6 questions)

• What to check in a PT report: your result and unit, the assigned value and how it was set, σpt, the number of results and your score.
• Peer groups, and how a method bias shared by a group differs from a fault in one laboratory.
• Spotting trends across rounds: drift, runs on one side of zero, repeated questionable scores and sudden changes.
• Reading a Youden plot of two samples to tell systematic error from random error.

D6. Investigation and corrective action (6 questions)

• Why you investigate before you correct.
• Where causes usually lie: clerical, method, equipment, personnel, the PT item and the provider's evaluation.
• The steps of a corrective action, from the clerical check to confirming the fix worked.
• How to respond to a single questionable score compared with a repeated one.

Question types

Single choice. Pick the one best answer.

Choose-2 multiple response. Pick exactly two answers. You get the mark only if both are correct.

Numeric entry. Calculate and type a number, for example a z score from the values given. The question tells you the units and the number of decimal places. You will need a calculator.

Every question is worth one mark. Wrong answers do not lose marks.

Many questions describe a short scenario, such as a PT report extract or a run of scores, and ask what it shows or what you should do.

How to prepare

The six course modules are free. Each one matches a domain and has an animated lesson, written notes and a short practice check. The course is recommended but not required.

1. Work through the six modules in order. Modules 3 and 4 carry the most weight.
2. Practise the calculations by hand: a z score, z′, ζ, En, and one round of Algorithm A.
3. Re-read the notes for any practice check you got wrong.
4. Have a handheld calculator ready before you start.

What the exam does not test

• Any software product, including EqasOnline's own software.
• The text of any standard, or clause numbers from memory.
• Clinical or analytical knowledge of any particular test or measurand.
• How accreditation bodies assess laboratories.
• Statistical methods beyond those in the course, such as other robust estimators or mixture models.
• How to estimate measurement uncertainty for your own method. Where a question needs an uncertainty, it gives you the value.
• The law or regulations of any particular country.

Changes to this blueprint

We may update the blueprint. We publish each version with its date. A change applies only to attempts that start after it takes effect.