Research & Evidence-Based Medicine

20 learning units • 100 chapter sections • 200 explained questions. Build a question, judge the evidence and connect the answer with the person receiving care.

Original RAHBAR study material for the Year 3 learning pathway. Educational examples support supervised learning; institutional research and clinical requirements still apply. References & further reading ↓

MODULE 05 / 20

Variables, Measurement & Data Quality

Define what is measured, how it is measured and which errors could change the answer.

Choose an answer and check it immediately. Change your choice to try again. This is a self-study exercise; results are not saved.

Question 01. Blood group is best classified as which variable type? A. Nominal categoricalB. ContinuousC. Ordinal severityD. A time-to-event variable

Question 02. Mild, moderate and severe pain categories form which scale? A. Nominal with no orderB. OrdinalC. A continuous ratio scaleD. An exact event count

Question 03. A scale consistently reads five kilograms too high. What describes it? A. Accurate because repeatableB. Randomly error-freeC. Proof of perfect validityD. Repeatable but inaccurate

Question 04. Why write an operational definition for adherence? A. To state precisely how adherence will be measuredB. To guarantee every patient adheresC. To remove the need for follow-upD. To choose a favourable definition after analysis

Question 05. Two raters correlate highly but one scores everyone ten points higher. What is uncertain? A. Whether their rankings correlateB. Whether both produce numbersC. Whether a systematic difference existsD. Agreement between their measurements

Question 06. Which action best preserves a data-cleaning audit trail? A. Overwrite all originals without notesB. Retain raw data and record correctionsC. Delete unexpected values automaticallyD. Replace all missing values with zero

Question 07. Why distinguish missing blood pressure from zero? A. They are always interchangeableB. Missing values prove normal pressureC. Zero automatically corrects biasD. Zero would be an observed value rather than missing information

Question 08. Which procedure helps reduce observer-related measurement bias? A. Revealing allocation to every assessor unnecessarilyB. Changing definitions between groupsC. Measuring only improved participantsD. Standardised blinded outcome assessment

Question 09. What belongs in a data dictionary? A. Only the article titleB. Only significant p-valuesC. Variable definitions, units and permitted valuesD. Only the investigator’s surname

Question 10. How should the effect of misclassification be judged? A. Assume it always eliminates associationsB. Assume it always exaggerates associationsC. Examine its mechanism and assumptionsD. Ignore whether errors differ by group

0 / 10 answeredReady for assessment →

References & Further Reading

Use the full methods and relevant chapters when appraising a paper. These sources support further study; the examples and questions above are original teaching exercises.

Reference review: 25 September 2026. Consult current institutional guidance for project approval and clinical decisions.