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Z-score normalization: Difference between revisions

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Data [[normalization]] in [[machine learning]] is a critical preprocessing step that helps boost the performance of many [[algorithm]]s. Normalization involves scaling data to a specified range or distribution to reduce the impact of differences in scale or units of [[feature]]s.
Data [[normalization]] in [[machine learning]] is a critical preprocessing step that helps boost the performance of many [[algorithm]]s. Normalization involves scaling data to a specified range or distribution to reduce the impact of differences in scale or units of [[feature]]s.


==Example==
==Simple Example==
A [[feature]] with the mean of 500 and a standard deviation of 100.
A [[feature]] with the mean of 500 and a standard deviation of 100.
{| class="wikitable"
{| class="wikitable"
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#These values correspond to Z-scores for each data point.
#These values correspond to Z-scores for each data point.


==Example==
==Real-life Example==
Let us assume we have a dataset with two features, height (in cm) and weight (in kg), that we would like to apply Z-score normalization to. The data values for these features can be seen in the following table:
Let us assume we have a dataset with two features, height (in cm) and weight (in kg), that we would like to apply Z-score normalization to. The data values for these features can be seen in the following table:


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By applying the formula for Z-score normalization to each data value in our dataset, we can calculate Z-scores individually. The results are displayed in the following table:
By applying the formula for Z-score normalization to each data value in our dataset, we can calculate Z-scores individually. The results are displayed in the following table:


Height (cm) | Weight (kg)
{| class="wikitable"
| 0.39 | 0.22
|
| -0.26 | 0.08
|-
| 1.04 | 1.28
! Height (cm) Z-score
| -1.17 | -1.12
! Weight (kg) Z-score
| -0.
|-
| 1.27807 || 1.30781
|-
| -1.46065 || -0.71457
|-
|}


==Explain Like I'm 5 (ELI5)==
==Explain Like I'm 5 (ELI5)==