What is Bell Curve?

A bell curve is a graphical representation of data and is shown like a bell. The top of the bell curve shows the mean and median values. Below it, in the descending parts lie the low tier values.

In the HR domain, they are used to measure employee performance for performance appraisal.

During a performance appraisal process, a bell curve can be used to divide employees into three different categories:

• Top performers who make up 20% of the surveyed demographic.
• Average performers, who make up 70% of the group surveyed.
• Low performers who make up the remaining 10%

These categorizations can help companies recognize top performers for retention efforts and create targeted upskilling plans for low performers.

What are the advantages of using the bell curve?

The advantages of the bell curve include:

• By assessing their performance data, an employee’s suitability for their role can be identified using a bell curve.
• Skill gaps can be spotted as employees are evaluated based on their competencies
• Regular assessment can also facilitate a consistent professional development plan which can contribute to employee engagement.

What are the demerits of using the bell curve?

While the bell curve is exceedingly popular, it is a very restricted ranking process (hence the name ‘force ranking’). This can be inadequate for certain scenarios and job roles.

• The bell curve scales are extremely inflexible and poorly fit smaller workforces.
• With the bell curve scales, companies do not get an opportunity to measure the performance of their employees on an individual basis.
• The comparison factor can also be demoralizing for certain employees and result in unnecessary feelings of antagonism and resentment among employees.

Bell Curve – FAQs

How is a bell curve used in performance reviews?

A bell curve is used to map employee performance with the majority of the employees being given an average rating, and thereby falling close to the median range.

What is a 5-point rating in a bell curve?

A bell curve graph that is divided into five performance ranges uses a 5-point rating to grade performers. The divisions are arranged in ascending order of performance.