Normalization process

Normalization process

The normalization process in competitive exams like banking exams (e.g., IBPS PO, SBI PO, IBPS Clerk) is a statistical method used to ensure fairness when an exam is conducted over multiple shifts or days with different difficulty levels. It adjusts the scores of candidates across different exam sessions to account for variations in question difficulty, thereby ensuring a level playing field for all aspirants.

Why is Normalization Required?

Banking exams are often conducted in multiple shifts, typically over several days, to accommodate the large number of candidates. While exam bodies aim to keep the difficulty level of each shift similar, slight variations in difficulty may occur. As a result, candidates who take the exam in a relatively more difficult shift may score lower than those in an easier shift, even though their abilities are comparable.

The normalization process addresses this issue by adjusting scores to ensure that candidates from different shifts are evaluated fairly, regardless of variations in difficulty.

How Does the Normalization Process Work?

Normalization is generally carried out using a statistical formula based on mean and standard deviation. The process converts the raw scores of candidates into normalized scores, making it easier to compare the performance of candidates who appeared in different shifts.

The normalization process is typically applied in two steps:

1.       Standardization of Marks: The scores of candidates are standardized to a common scale using a mathematical formula. This helps adjust for any discrepancies in the difficulty levels of different shifts.

2.      Final Score Calculation: Once the marks are standardized, the final score is calculated by adjusting the raw score based on the performance of candidates in that particular shift.

Common Formula Used in Normalization

The formula used for normalization in banking exams is generally based on z-scores or a variant of it. Here’s a simplified version of the formula often used:

Normalized Score=(X−μ)σ×(Max_Marks−Min_Marks)+Min_MarksNormalized\ Score = \frac{(X - \mu)}{\sigma} \times (Max\_Marks - Min\_Marks) + Min\_MarksNormalized Score=σ(X−μ)​×(Max_Marks−Min_Marks)+Min_Marks

Where:

• X = Raw score of the candidate
• μ\muμ = Mean of the raw scores in the candidate's session
• σ\sigmaσ = Standard deviation of the raw scores in the candidate's session
• Max_Marks = Maximum marks obtainable in the exam
• Min_Marks = Minimum marks obtainable in the exam

This formula adjusts the candidate’s raw score based on the mean and standard deviation of the scores in their specific session, and then scales it to a common range of marks.

Steps in the Normalization Process

1.       Collect Scores: The exam authority collects the raw scores of all candidates in all shifts.

2.      Calculate Session-Wise Statistics:

o    Calculate the mean and standard deviation of raw scores for each session.

o    Identify the maximum and minimum raw scores across all shifts.

3.      Apply Normalization Formula: The formula is applied to the raw scores of each candidate to produce a normalized score.

4.      Final Score: The final score, after normalization, is used for creating merit lists and determining whether a candidate qualifies for the next stage (Mains, Interview, etc.).

Example of Normalization

Let’s consider an example where an exam has two shifts, and the difficulty level of Shift 2 is higher than Shift 1:

Scenario:

• Shift 1: Candidates score higher because the paper is relatively easier.
• Mean score in Shift 1: 75
• Standard deviation in Shift 1: 10
• Shift 2: Candidates score lower because the paper is more difficult.
• Mean score in Shift 2: 65
• Standard deviation in Shift 2: 15

A candidate who appeared in Shift 1 might score 80 (above the mean), while a candidate in Shift 2 scores 70 (above the mean for Shift 2).

Without normalization, the candidate from Shift 1 would be ranked higher. However, after normalization, the candidate from Shift 2 will likely receive a slightly higher normalized score due to the relative difficulty of the paper in Shift 2.

Benefits of the Normalization Process

1.       Ensures Fairness: Normalization makes the competition fair by ensuring that candidates who appeared in a more difficult shift are not unfairly disadvantaged.

2.      Eliminates Shift Variability: It accounts for any variations in question difficulty across shifts, ensuring that candidates' performance is evaluated on a comparable scale.

3.      Consistency: It allows the exam authority to maintain consistent and standardized results across multiple sessions of the same exam.

Challenges of Normalization

1.       Perception of Unfairness: Some candidates may perceive normalization as unfair, especially if they feel that their raw score was high in an easier shift but was reduced after normalization.

2.      Complexity: The normalization process can be complex, and candidates may not always understand how their final scores were adjusted, leading to confusion or dissatisfaction.

3.      Extreme Scores: In some cases, candidates with extreme scores (either very high or very low) may see more significant fluctuations in their normalized score, which can affect their final ranking.

Normalization in Different Banking Exams

1.       IBPS PO/Clerk/So: Normalization is applied in Prelims and Mains for both Officer and Clerical posts since the exams are held in multiple shifts.

2.      SBI PO/Clerk: SBI uses the normalization process for both Prelims and Mains exams, as these exams are also conducted in multiple shifts.

3.      RBI Grade B: Since the RBI Grade B Prelims and Mains are conducted over multiple days and shifts, the scores are normalized before preparing the merit list.

Key Points for Candidates Regarding Normalization

• Focus on Relative Performance: Since the difficulty of each shift is accounted for, your rank depends on how well you perform relative to others in your shift, not just the absolute score.
• Prepare Consistently for All Sections: Since normalization applies across all sections, it's important to perform consistently well in each section of the exam to maximize your final normalized score.
• Don’t Worry About Shift Difficulty: Even if you feel that your shift was more difficult, trust that the normalization process will balance the results across all shifts.

Conclusion

The normalization process is a crucial element of banking exams that ensures fairness across multiple exam shifts with varying levels of difficulty. While the exact formula may vary between exams, the overall objective remains the same: to adjust scores so that candidates across different shifts are evaluated fairly. Understanding the normalization process helps candidates remain confident and focused, knowing that their performance will be assessed equitably regardless of the shift they are assigned.