Statistical infrequency

• Statistical infrequency

  • Occurs when an individual has a less common characteristic
  • A characteristic that is statistically rare
• Normal distribution curve

  • 68% of the sample is within the average range
  • 95.5% of the sample is within 2 standard deviations
  • 99.7% of the sample is within 3 standard deviations
• Real world application

  Statistical infrequency is key in clinical practice for diagnosis and symptom severity assessment, like in intellectual disability (IQ below 70) and depression evaluation (Beck’s depression inventory)
• Unusual characteristics can be positive

  statistical infrequency is important in clinical practice for assessment, but it's not enough to define abnormality on its own because rare traits can also be positive. eg, having a high IQ.