Questions tagged [data-leakage]
The data-leakage tag has no usage guidance.
61
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How high of a correlation coefficient of a feature with a target variable is considered too high?
Currently my classification model is doing too well on all of the train, validation, and test datasets. I'm assuming there is a data leakage in the features, and therefore I've computed the ...
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What is the best way to avoid data leaking in timeseries forecasting multiple labels?
I'm predicting crypto pairs volume. I want to increase my accuracy by using one model for different pairs. Question is how to avoid timedata leaking?
Example n - pairs, t- time, m - features for each. ...
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22
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Computer Vision - is splitting by annotation considered data leakage?
We are using a COCO like dataset, with around 1500 images and 4700 annotations.
We want to define our train-test dataset split.
Will splitting our dataset by annotations cause data leakage? We fear ...
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0
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Why does Time series split cause data leakage from future data?
There are lots of websites saying time series split may cause data leakage.
The idea for time series splits is to divide the training set into two folds at each iteration on condition that the ...
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1
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Is this a case of leakage or not?
I have a set of data on individuals' performance in 1960,1970,1980 and 1990, e.g. chess rating in those years for a bunch of players with 40-year careers. I've been asked to build a model to predict ...
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Is it unethical to gather data from data leaks about demographics?
Sorry if this is the wrong SE, but in my mind it made the most sense to ask this here.
My question is related to specifically collecting information about a target demographic, not individuals which ...
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2
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what qualifies as a data leakage?
I am currently working on a binary classification problem using imbalanced data. The algorithm that I am using is random forest. The problem is about predicting whether each sales project will meet ...
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42
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Order of preproccesing, avoiding leakage and metrics
I have a dataset with ~40k records and 16 columns (including the target) and I want to understand the correct process behind whole data science proccess.
This is what I did:
Performed an EDA which ...
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0
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1
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53
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Fit multiple models e.g classifiers -> stacking -> calibration without data-leak or getting too many datasets
I have some data X on which I want to do the following:
Train two models; SVM and Logistic Regression
Use a stacking classifier based on the models from (1)
...
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0
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19
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Word2Vec Data Leak
I want to train a machine learning model that can determine the sentiment of tweets about different stocks.
To do this I have a dataset, lets call it A. For dataset A about 30% of the data is labelled....
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1
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47
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using a feature that is only available during training
I'm working on a project that aims to classify JIRA issues into their relevant owner group.
An issue has the following text features:
Summary
Description
Comments
all of which are text based.
During ...
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1
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27
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Data Leakage possibility related to replacing rare values on a categorical column
I am exploring the possibility of data leakage for categorical columns, replacing rare values with category 'Other'
Let's say I have a DF with 40 categorical columns. I will check each of them, find ...
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vote
1
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128
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Revisit - Encoding before vs after train test split?
Background: Like a good data scientist, I planned to fit my encoder on my training set and use it to transform my test set. However, when I tried to transform my test set, the encoder threw an error....
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39
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Can using model evaluation metrics to choose a model cause data leakage?
I was reading a blog post about improving machine-learning model train/validate/test splits. Towards the end was this remark:
I say we should be more creative in the way we test machine learning ...
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0
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Data Leakage (specific case with standardization)
I read a few blog posts and found some books that caution against data leakage when adjusting the training data using any information from the held out datasets. For example, if I were to standardize ...
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2
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2
answers
290
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Stacking: Use predictions of train or test to create features for level 1 classifier
The question is pretty simple.
In stacking, the predictions of level 0 models are being used as features to train a level 1 model.
However, the predictions of what data? Intuitively it makes more ...
- 636
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49
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Machine learning data leakage
I have a dataset with Information about a transaction that a customer made in the store.
the target is Indication of whether fraud was committed in the transaction.
One of my feature is ...
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1
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97
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Avoid leakage in NLP extraction
What is best practice for applying traditional NLP extraction techniques a pre-processing for ML models?
Given a pipeline:
Collect raw data.
Parse full data set with a variety of traditional NLP ...
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1
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118
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Why leaky features are problematic
I want to know why leaky features are problematic in machine learning/data science. I'm reading a book that uses the Titanic dataset for illustration. It says that the column ...
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1
answer
47
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Can I create a new target value based on the average target value of same data points for regression?
I am trying to predict profit of retail stores. The orginal dataframe looks like this:
Store No
feature A
feature B
year
profit
A
1
2
2016
20000
A
1
2
2017
40000
B
4
3
2017
50000
B
4
3
2018
40000
...
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0
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118
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Is data leakage giving me misleading results? Independent test set says no!
TLDR:
I evaluated a classification model using 10-fold CV with data leakage in the training and test folds. The results were great. I then solved the data leakage and the results were garbage. I then ...
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1
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114
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How does a data leakage work?
I'm working with panel data - every row represents a timestamp (observation) and there are multiple rows for a single timestamp (around 20 rows each). I have a total of 8719 unique timestamps.
...
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2
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How to generate test set with no data-leakage using multiple columns
I am developing a fraud detection algorithm. Among other things, my dataset contains the phone number, email address and a few other fields that should uniquely identify a user (let's call them "...
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884
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Why label encoding before split is data leakage?
I want to ask why Label Encoding before train test split is considered data leakage?
From my point of view, it is not. Because, for example, you encode "good" to 2, "neutral" to 1 ...
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How to fit Word2Vec on test data?
I am working on a Sentiment Analysis problem. I am using Gensim's Word2Vec to vectorize my data in the following way:
...
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1
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49
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Preprocessing for the final model to be deployed
Typically for a ML workflow, we import the data (X and y), split the X and ...
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4
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1
answer
217
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What can I do when my test and validation scores are good, but the submission is terrible?
This is a very broad question, I understand and I'm totally fine if someone believes it's not appropriate to do it. But it's killing me not to understand this...
Here's the thing, I'm doing a machine ...
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1
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Splitting before tfidf or after?
When should I perform preprocessing and matrix creation of text data in NLP, before or after train_test_split? Below is my sample code where I have done ...
- 1,886
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votes
1
answer
137
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Can data leakage be sometimes acceptable?
I have recently started using kaggle and I have stumbled on a few examples of practices I would consider do be data leakage. Many of them were done by people well established on the platform and I ...
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1
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222
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Data Leakage when preprocessing categorical features?
I am fairly new to machine learning. I came across the concept of Data Leakage. The article says that always split the data before performing preprocessing steps.
My question is, do steps such as ...
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Is there potentially data leakage during imputation for time-varying sensor data?
I have a time-varying dataset that contains some missing data. I have sensors that continuously monitor some properties at evenly-spaced intervals and I would like to impute the missing values using ...
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2
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1
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107
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Information leakage when train/test are truly i.i.d.?
I am well aware that to avoid information leakage, it is recommended to fit any transformation (e.g., standardization or imputation based on the median value) on the training dataset and applying it ...
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2
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174
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Does binning a time series with pd.qcut (using quantiles) create data leakage?
Let's say I want to predict whether a company will default on it's debt at some point in time (so binary classification) and one of the time series variables I'm using is the "revenue" of ...
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0
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Data\Feature Leakage - feature too close to target?
In General:
The target itself built from very correlated features, because there is no ground truth - only rule based one.
I have a problem in the following method:
Output: binary. built from ...
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1
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1k
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K-Fold cross validation and data leakage
I want to do K-Fold cross validation and also I want to do normalization or feature scaling for each fold. So let's say we have k folds. At each step we take one fold as validation set and the ...
user109341
2
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1
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129
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How to split up my dataset in a train and testset, in order to prevent data leakage?
I realize that this could be considered a duplicate of this question, Is using samples from the same person in both trainset and testset considers being a data leakage?, where it is stated that "...
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1
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Is it right to maintain the train distribution in test set for unbalanced data?
If the training set was unbalanced the chances are the model will be biased. But if the data distribution in the test set is the same distribution as the train set, this kind of bias is not going to ...
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4
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3k
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Does label encoding an entire dataset cause data leakage?
I have a dataset on which one of the features has a lot of different categorical values. Trying to use a LabelEncoder, OrdinalEncoder or a OneHotEncoder results in an error, since when splitting the ...
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1
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Is using samples from the same person in both trainset and testset considers being a data leakage?
Suppose a neural network is built for a binary classification problem such as recognize the face as a smiley face or not, by using a dataset of 1000 persons and each person has ten images of his face.
...
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0
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308
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Will setting up time series data in this way cause data leakage?
I am trying to predict future stock market values using a gradient boosted tree model. As far as I know, gradient boosted trees use the data in one row, and only that row, to predict the target ...
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1
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Can I apply feature selection before splitting by requiring selection occurs > 90% of time
I want to move the feature selection step to before splitting to save time and allow bigger input dataset. If, in repeated subsamples, a feature is selected in over X percentage of cases I will keep ...
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1
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367
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Mean encoding in times series
Considering a TS from 1-5 blocks and using 1-4 block as train data.
Is it invalid to build mean encode on whole train data / or I should mean encode block 1 / block 1-2 / ... / block 1-2-3-4 ?
Edit 1 :...
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Need help understanding data leakage
I am a newbie to this stuff so I am sorry if my question is stupid~
I need help understanding what data leakage between X_train and X_test is and when exactly it happens.
I am currently working on a ...
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Normalizing dependent feature by one of the independent ones
I have a data set with three different features (x1, x2, x3) and I am going to use a regression model to predict y based on the features.
x3 is the total amount of money that a customer invest and y ...
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0
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Identifying possible data leakage
I am building a binary classification model for imbalanced dataset using XGBoost. I tuned the hyperparameters for four different models based on 2 training datasets and 2 optimization metrics.
Class ...
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0
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418
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Data leakage in bidirectional LSTM timeseries data
Does it cause data leakage to train a bidirectional LSTM on data where a user can be a sample in the training data multiple times?
Each row is a snapshot at a different point in time for a given ...
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Is data leakage in time series due to both I's of the IID principe or only one?
I am sure that the Independent part of the IID principle gives you data leakage because of the correlation. But the identical part I am not so sure. Identical in time series means that your data is ...
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2
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Does using user-specific accumulative variables causes data leakage?
Let's say I have a scenario in which my observational unit is a bill that was issued after a certain service was given and my goal is to predict if this bill is going to be paid or not. I have users ...
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390
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How to keep the test data from leaking into the training process of a machine learning algorithm?
I read in many different sources that I need to split my data into a training set and a test set. Then I have to make sure that the algorithm is trained only on the training data, and do my best to ...
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Frequency/Count encoding
How do I perform frequency/count encoding for a train and test set?
The implementations of this encoding I've seen simply frequency encode the categorical variables on a particular dataset (no ...
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