The Ministry of Railways has announced that the Railway Recruitment Board (RRB) will implement a percentile-based normalisation methodology for scoring in the upcoming Computer Based Test (CBT) exams. This approach aims to ensure fair assessment by adjusting scores across different shifts, thereby creating a level playing field for all candidates.
According to the RRB’s official notification, the normalisation methodology involves converting candidates’ raw scores to percentile scores, which account for the relative performance of all examinees. Percentile scores are not equivalent to the percentage of marks but indicate the percentage of candidates who scored equal to or below a given candidate in their exam shift.
How Percentile Scores Are Calculated
Each candidate’s score will be normalised to a percentile ranking on a scale of 100 to 0. The highest scorer in each shift will receive a percentile score of 100, representing the top percentile for that shift. For those scoring between the highest and lowest marks, their raw scores will be converted to percentiles. These normalised scores will then be used for merit list preparation instead of raw scores.
The percentile score formula is as follows:Percentile Score=(Number of candidates with equal or lower raw scoresTotal number of candidates in the shift)×100\text{Percentile Score} = \left( \frac{\text{Number of candidates with equal or lower raw scores}}{\text{Total number of candidates in the shift}} \right) \times 100Percentile Score=(Total number of candidates in the shiftNumber of candidates with equal or lower raw scores)×100
The final RRB score, used for compiling results, will merge all percentile scores from each shift. To reduce ties, scores will be calculated to five decimal places.
Tie-Breaking Rules and Minimum Eligibility Marks
In cases where multiple candidates achieve the same percentile, tie-breaking will follow these criteria:
- Candidates will be ranked by age, with older candidates given priority.
- If the age is identical, alphabetical order of the candidates’ names (A-Z) will determine the ranking.
For inclusion in the merit list, candidates must meet minimum score requirements:
- UR and EWS: 40%
- OBC (Non-creamy layer): 30%
- SC: 30%
- ST: 25% (30% for Level-1 exams)
Base Shift and Calculation of Normalised Marks
To account for differences in exam shifts, a “Base Shift” will be selected, defined as the shift with the highest average score (mean) among all shifts, provided it meets the attendance threshold. If multiple shifts share the highest mean, factors such as the highest individual marks and attendance counts will help determine the base shift. Candidates’ normalised scores will be adjusted according to this base shift using standard interpolation formulas.
Key Advisory for Candidates
RRB advises candidates to consult only official RRB websites for authentic updates and warns against unauthorised sources or touts offering fraudulent job placement promises. Selection will be merit-based, relying exclusively on CBT results.
For further details, candidates are encouraged to review the official notice available on RRB websites.
