# Weak value controversy

## TL;DR

This paper reviews the debate over the interpretation and practical utility of weak values, emphasizing their role in precision measurements despite statistical controversies.

## Contribution

It clarifies the statistical nature of weak values and defends their usefulness in amplification techniques for small effect measurements.

## Key findings

- Weak values enable useful amplification in precision measurements.
- Experiments with anomalous weak values demonstrate practical advantages.
- The statistical interpretation of weak values is consistent with their role as system properties.

## Abstract

Recent controversy regarding the meaning and usefulness of weak values is reviewed. It is argued that in spite of recent statistical arguments by Ferrie and Combes, experiments with anomalous weak values provide a useful amplification techniques for precision measurements of small effects in many realistic situations. The statistical nature of weak vales was questioned. Although measuring weak value requires an ensemble, it is argued that the weak value, similarly to an eigenvalue, is a property of a single pre- and post-selected quantum system.