Probability vs. Confidence Levels

I'm looking at the work that a coworker is working on and I want to
see if someone can help me to understand where he went wrong or where
I want wrong in understanding.

Situation: He wants to determine what the confidence level is for
detecting faults inserted into a circuit card. He uses the
probability formula, but ties it to a confidence level.

For example: The current process calculates the percent detection as
being equal to the percentage of sampled faults that were
detected( e.g. - if 18 of 20 faults inserted were detected the percent
detection would be 18/20=.90 or 90%)

In reality, a program that detects 18 of 20 sampled faults has only a
32.3% probability (confidence level) of 90% fault detection. He used
the probability formula to get this number)

From what I understand, which isn't much, probability involves random
variables and confidence refers to a constant even if it is an unknown
constant.

What I think he should of said was, The probability of at least one
non-detect(success) is 67.7% given the true probability is 10%. This
in no way has anything at all to do with confidence levels.

I'm I understanding this correctly or can the above be stated as a
confidence level?
Any help would be greatly appreciated.

.

Relevant Pages

  • Re: Probability vs. Confidence Levels
    ... but ties it to a confidence level. ... The current process calculates the percent detection as ... being equal to the percentage of sampled faults that were ... 32.3% probability of 90% fault detection. ...
    (sci.stat.edu)
  • Re: Probability vs. Confidence Levels
    ... probability formula, but ties it to a confidence level. ... being equal to the percentage of sampled faults that were ... The power of a test (equal to one minus the probability of incorrectly ...
    (sci.stat.edu)
  • Re: The Consise Cantor Disproof
    ... > confidence level of having being randomly generated. ... same probability distribution, AND 3) that each event has ... you suck even worse at statistics than ...
    (sci.logic)
  • Re: Two EPR questions
    ... > probability of coincidental detection, in the ideal, is ... > polarization of light incident on A and B for any given ... > coincidence interval). ...
    (sci.physics.research)
  • Re: Improving 2-channel recommendations!!!
    ... > success rate of 50% and perfect detection would be 100%, ... corresponding to an actual detection rate of at least ... > performance is usually regarded as substantially better than chance. ... > you know what a confidence level and a confidence set are, ...
    (rec.audio.opinion)