Difference between revisions of "Test"

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==Introduction==
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===False Positive Rate (FPR) in Machine Learning==
A false negative (FN), in machine learning, is a type error that occurs when a model incorrectly classes a sample as negative even though it is actually positive. A false negative (FN) is when a model fails identify a positive sample.
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The false positive rate (FPR), in machine learning, is a measure for the percentage of negative instances that are incorrectly categorized as positive. It is simply the sum of the number of falsely positive instances and the total number negative instances. FPR is often used with the true positive rate, also known as recall or sensitivity, to evaluate the performance and effectiveness of a binary classifier.
  
FNs are especially important in certain applications, such as medical diagnosis or fraud detection, where it is costly to fail to identify positive samples.
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[[Sensitivity and Specificity|Sensitivity]] and [[Specificity (medical test)|specificity]] are two other measures of a binary classifier's performance that are related to the FPR. Specificity is the ratio of true negatives to all negatives, while Sensitivity measures the ratio of true positives to all positives.
  
==Examples==
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In a [[Receiver operating characteristic|receiver operating characteristic (ROC) curve]], the FPR is plotted against the true positive rate. The ROC curve shows the trade-off between FPR and TPR at different threshold settings for a binary classifier. The ROC curve can be used to indicate the performance of the classifier in general. Each point represents a threshold setting.
In a medical diagnosis scenario, a FN could occur when a model that is supposed to identify patients with a specific disease incorrectly classifies a patient's health as healthy, when in fact they have the disease. This could result in the patient not receiving the treatment they need, which could have severe consequences.
 
 
 
A fraud detection scenario would see a FN if a model that is designed to detect fraudulent transactions incorrectly classifies a fraudulent deal as legitimate. This could result in financial loss as the fraudulent transaction is approved.
 
 
 
==Measures==
 
There are many measures that can be used to assess the performance of a model, including the false positive rate (FNR), and the false discovery (FDR).
 
 
 
FNR is the sum of the total number positive samples and the number of FNs. It is the percentage of positive samples incorrectly classified as being negative.
 
 
 
The FDR is the sum of the number of FNs and the total number that were predicted to be positive. It is the percentage of negative samples that are incorrectly classified to be positive.
 
  
 
==Explain Like I'm 5 (ELI5)==
 
==Explain Like I'm 5 (ELI5)==
False negatives are when a computer claims something is false when it is actually true. A false negative is when a computer claims that a person isn't sick, but in fact they are. This can lead to the person not receiving the medication they need.
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False positive rate (FPR) can be used to determine how often a test which is supposed to give "no" actually gives "yes". False positives can be for example when a test claims you have a disease but you don't really have it. It is important to understand how often this happens in order to decide if the test should be used.

Revision as of 09:50, 25 January 2023

=False Positive Rate (FPR) in Machine Learning

The false positive rate (FPR), in machine learning, is a measure for the percentage of negative instances that are incorrectly categorized as positive. It is simply the sum of the number of falsely positive instances and the total number negative instances. FPR is often used with the true positive rate, also known as recall or sensitivity, to evaluate the performance and effectiveness of a binary classifier.

Sensitivity and specificity are two other measures of a binary classifier's performance that are related to the FPR. Specificity is the ratio of true negatives to all negatives, while Sensitivity measures the ratio of true positives to all positives.

In a receiver operating characteristic (ROC) curve, the FPR is plotted against the true positive rate. The ROC curve shows the trade-off between FPR and TPR at different threshold settings for a binary classifier. The ROC curve can be used to indicate the performance of the classifier in general. Each point represents a threshold setting.

Explain Like I'm 5 (ELI5)

False positive rate (FPR) can be used to determine how often a test which is supposed to give "no" actually gives "yes". False positives can be for example when a test claims you have a disease but you don't really have it. It is important to understand how often this happens in order to decide if the test should be used.