Search the courses, subjects, tracks, games and features, or jump straight to a page.
Learn it your way
A short class with Sarah and her students. The other ways are under More.
Sign up free to listen. Transcripts are free to read.
Today, we're going to discuss Recall, also known as sensitivity. Can anyone remind me what Recall measures in our AI models?
Isn't recall about how many actual positive cases we correctly identify?
That's correct! Recall tells us the proportion of true positives. So, if we think of our formula, Recall equals TP over the sum of TP and FN. How do you think this is applied in real-world scenarios?
I think it’s really important for things like medical tests, right? Missing a positive case there can be serious!
Exactly! In medical diagnostics, we prioritize recall because failing to identify a disease can have critical implications. Remember, high recall can save lives!
Let’s calculate recall together. If we have 80 true positives and 20 false negatives, how would we find the recall?
We would use the formula TP divided by TP plus FN, so it would be 80 divided by 80 plus 20.
Great! What does that give us?
That would be 80 divided by 100, which equals 0.8 or 80% recall.
Exactly! A recall of 80% means our model correctly identifies 80% of the actual positives. Remember, a high recall is vital, especially where missing positives could have serious consequences.
How does recall compare to precision? Can anyone explain the difference between these two metrics?
Recall focuses on capturing actual positives, while precision more on the accuracy of predicted positives, right?
Exactly! Precision tells us how many of the predicted positives were correct, whereas recall tells us how many of the actual positives were captured. In what situations might we choose to emphasize recall over precision?
Like in cancer screening tests; we want to catch as many real cases as possible.
Right again! In contexts like that, you’d rather have a higher recall even if it means some false positives.
Recall is very important in areas beyond healthcare. Can anyone think of other domains where recall might be prioritized?
Maybe in spam detection for emails? If a spam email gets through, it could be bad!
Good point! In spam detection, it’s often more critical to ensure that spam is caught, sometimes at the risk of legitimate emails being mistakenly flagged.
So, it’s all about finding the right balance depending on each situation?
Exactly! Always analyze context and prioritization of recall versus precision in your evaluations.
Measures how many actual positives are correctly predicted by the model.
Another term for recall, is used to highlight the critical need to identify actual positive cases.
Correctly identified positive cases.
Actual positives that were not predicted correctly.
Recall is key for safety's call, catch disease so risk is small!
Imagine a doctor with a checking list; missing a vital sign means they might miss the gist. Recall is their compass, steering them right, helping catch positives, saving lives in the night.
Think of 'TRAP': True positives are captured with Recall—helps you catch the vital with precision.
R.A.C.E - Recall is All about Correctly identifying everyone: (positives) is what makes a model great!
Term
What does recall measure?
Click to flip
Term
What is the relationship between recall and sensitivity?
Click to flip
A metric that measures the proportion of true positive cases that are correctly identified by a model out of all actual positives.
Another name for recall; it emphasizes the model's ability to identify positive instances correctly.
The number of correctly predicted positive cases.
The count of actual positive instances that were incorrectly predicted as negative.
Recall, also known as sensitivity, measures how effectively a model identifies actual positives among the total positives.
Recall is a crucial metric in evaluating AI models, especially in scenarios where missing a positive instance can lead to serious consequences, such as in medical diagnoses. It quantifies the proportion of true positive results from the total actual positives.
Recall, also referred to as sensitivity, is an important evaluation metric in AI model performance assessment. It specifically addresses the model's ability to correctly identify actual positive instances from within the population of all actual positives. The formula for calculating recall is:
Where:
Recall plays a critical role in various domains. For example, in medical diagnostics, failing to identify a disease can lead to severe outcomes. Therefore, a high recall value is vital. In many cases, especially when the cost of missing a positive is very high, a model's ability to recall positives takes precedence over precision. Consistently measuring recall alongside other metrics allows practitioners to strike a balance in performance, especially when applying AI models in sensitive environments.