Chapter 1: Introduction Flashcards

1
Q

What is a supervised learning model?

A

Building a statistical model for predicting an output based on one or more inputs

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2
Q

What is an unsupervised learning model?

A

There are inputs but no supervising outputs for the data

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3
Q

What is the formula to calculate accuracy using false positives, true positives, fase negatives, and true negatives?

A

Accuracy = (TP + TN) / (TP + TN + FP + FN)

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4
Q

What is the formula for precision?

A

TP/(TP+FP)

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5
Q

What does precision of a model reflect?

A

How accurate the positive predictions are

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6
Q

What is the formula for recall sensitivity?

A

Recall = TP/(TP+FN)

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7
Q

What does recall sensitivity indicate?

A

Measures the proportion of positive cases that are correctly identified by the model. Higj sensitivity indicates the model is good at identifying positive cases

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8
Q

What is the formula for specificity?

A

Specificity = TN/(TN+FP)

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9
Q

What does specificity indicate?

A

Measures the proportion of actual negative cases that are correctly identified by the model. High specificity indicates the model is good at identifying negative cases

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10
Q

What is the formula for the F1 score?

A

F1 = 2TP/(2TP + FP + FN)

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11
Q

What is the formula for mean squared error?

A

(1/n)*Sig{n=1 .. t}(et^2)
Where et is the error of observation t

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12
Q

What is the formula for mean absolute error?

A

(1/n)*Sig{n=1 .. t}(|et|)
Where et is the error of observation t

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13
Q

What is model bias?

A

The difference between the expected prediction and the correct model we are trying to predict for the given data points

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14
Q

What is variance?

A

The variability of the model estimate for given data points

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15
Q

What is the deviation/variance tradeoff?

A

The simpler the model, the higher the bias. The more complex the model, the higher the variance

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16
Q

What is a symptom of underfitting a model?

A

Higher training error, high bias, training error close to test error

17
Q

What is a symptom of overfitting a model?

A

Very low training error, high variance, training error significantly lower than test error