Confidence can be meaningfully related to positive predictive value (PPV) in the sense that both concepts reflect the accuracy of a belief or decision-making process.
Defining Positive Predictive Value (PPV)
In statistics and diagnostics, PPV refers to the probability that a positive test result is actually correct. It is given by:
This means PPV measures how often a "yes" or a "positive" prediction actually turns out to be right. A higher PPV means greater confidence that when a test or decision says "yes," it is indeed correct.
Confidence as an internal PPV
In human decision-making, confidence is essentially a personal positive predictive value—it represents how often our beliefs about success actually lead to real success.
- A confident person with high PPV predicts success and is often correct. They take actions believing they will succeed, and their track record supports this belief.
- A confident person with low PPV predicts success often but is wrong frequently. This is overconfidence—where beliefs and actual success rates don’t align.
- A person with low confidence but high PPV underestimates their predictive ability. They may hesitate even though their past successes suggest they should be confident.
Practical implication: Confidence as a predictive skill
If confidence is essentially how accurately we predict our own success, then improving confidence means enhancing our internal PPV—ensuring that when we expect to succeed, we are actually correct. Here’s how:
- Improve signal quality (true positives): Build competence by focusing on the key actions that consistently lead to success. Initially, it may not be obvious which actions matter most, but over time, patterns emerge. The more you refine your approach, the more often your confidence will be justified.
- Reduce False Positives: Avoid misplaced optimism by grounding confidence in real experience, feedback, and data. We often form beliefs based on imagined scenarios rather than reality, and while these perceptions shape our emotions, they don't always reflect actual outcomes. Regular self-checks and objective evaluation help keep confidence aligned with results.
- Adjust Prior Beliefs: If you find that you succeed more often than you expected, take time to reflect and recalibrate your self-perception. Confidence should grow in proportion to real, demonstrated ability—not just assumptions. Recognising past successes reinforces a more accurate and sustainable sense of confidence.
Thus, confidence is not just a feeling—it is a function of how accurately you predict your own success.
If your confidence is high but unreliable, it's just noise. If it's low but precise, you need to recalibrate and trust yourself more.