Machine learning is widely used for prediction, but not all data behaves the same. A common mistake is applying standard ML to time-dependent data without considering temporal order and dependencies, which these models don’t naturally capture.
Time series data reflects evolving patterns over time, unlike static snapshots. For example, sales forecasting differs from default risk prediction. In this article, you’ll learn the differences, use cases, and practical examples of Time series and Standard Machine Learning.
Standard machine learning usually refers to predictive modeling on static, unordered data. A model develops the ability to predict unknown data through training on labeled data. The classification task requires us to train our model using customer data which includes their age and income and behavior patterns to determine whether they commit fraud or not. The data samples are assumed to be independent: one row’s features and label don’t depend on another’s. The target variable gets predicted through model learning which identifies patterns that exist between different feature combinations.
Data treatment: Machine learning standard procedures treat every data point as a separate entity. The order of samples does not matter (e.g. shuffling training data won’t affect learning). The system treats every feature as if it has no specific time-based arrangement. Common assumptions include that training and test examples are drawn from the same distribution (i.i.d.) and that there is no built-in temporal autocorrelation.
Common assumptions: Models like linear regression or SVM assume independence between samples. They focus on capturing relationships across features within each example, not relationships across examples in time.
Each of these algorithms requires input through a constant feature set which remains unchanged for every instance. Engineers can introduce additional features to static tasks through methods such as one-hot encoding of categories and scaling of continuous values.
Here are some of the problems/scenarios in which standard machine learning works well:
The core concept of the time series data is that observations are being collected sequentially (e.g. daily, monthly, or by event order), and past values influence future data points. In simple terms, Time series data refer to observations collected at regular or irregular intervals of time. Unlike static data, time series data “provide a dynamic view of changes, patterns, and trends” rather than a single snapshot.
Data points include timestamps which enable the collection of additional data points that are typically spaced at regular intervals to identify patterns. Time series analysis explicitly uses this ordering.
For example, a model might predict tomorrow’s value based on the last 30 days of data. The data exhibits its distinctive characteristics which depend on how time functions as a fundamental element. The process creates two types of work which include future value predictions and chronological anomaly identification.
Time series data often exhibit different components and patterns that analysts in general try to identify and model:
By decomposing a series into these components, analysts can better understand and forecast the data.
<image: illustrating a time series often highlight these: a timeline chart might show a rising trend line plus repeating seasonal waves, plus random noise on top. (A simple illustrative diagram could be a plotted line chart of monthly sales with a rising trend and yearly seasonal peaks.)>
The selection of time series models happens because sequential patterns exist in both the data and the assigned task.
Time series analysis serves as the preferred method for studying time-dependent variable evolution when your data sequence follows chronological order. Time series analysis enables hourly electricity usage prediction and weekly inventory forecasting and sensor reading anomaly detection because it maintains data order and autocorrelation patterns.
In short Yes! You can use standard ML algorithms for time series analysis when you create suitable features through engineering work. The key is to turn the sequential data into a static supervised problem. Feature-based machine learning uses historical data points as input-output pairs by selecting past data as features through lag features and rolling statistics and other methods. The process of creating lag columns has already been demonstrated to us. You can calculate both moving averages and differences between values. The method involves creating time-dependent features which the system then uses for regressor and classifier training purposes.
The sliding window approach requires researchers to create a dataset which contains fixed-size windows of past data points that serve as training examples while the next value functions as the target. The following example shows this approach.
# Sliding-window transformation (array-based)
def create_sliding_windows(data, window_size=3):
X, y = [], []
for i in range(len(data) - window_size):
X.append(data[i:(i + window_size)])
y.append(data[i + window_size])
return np.array(X), np.array(y)
series = np.arange(10) # example data 0,1,...,9
X, y = create_sliding_windows(series, window_size=3)
print(X, y)
The code generates input-output pairs through the expression X[i] = [i, i+1, i+2], y[i] = i+3. The actual implementation requires you to utilize actual time series data which includes sales figures and multiple attributes for each time interval. You can apply standard ML models to the transformed data after the transformation creates a feature matrix which includes all necessary elements.
XGBoost and similar models can be surprisingly effective for time series forecasting if set up this way. The downside is you must carefully validate: use time-based splitting rather than random shuffles, and often retrain models as new data come in. The following diagram demonstrates how to implement XGBoost through lagged data.
from xgboost import XGBRegressor
# Suppose df has columns ['y', 'lag1', 'lag2']
train = df.iloc[:-10] # all but last 10 points for training
test = df.iloc[-10:]
model = XGBRegressor()
model.fit(train[['lag1', 'lag2']], train['y'])
predictions = model.predict(test[['lag1', 'lag2']])
Machine Learning Mastery states that XGBoost “can also be used for time series forecasting however it needs time series data to be converted into a supervised learning problem first”. The system provides flexible functionality because it delivers rapid model performance through optimized testing after users complete their feature development work.
LSTM (Long Short-Term Memory) and GRU (Gated Recurrent Unit) are specialized recurrent neural networks designed for sequences. The systems function to establish temporal relationships between data points over time. LSTMs use “memory cells” together with gating systems which enable them to store and delete data throughout extended periods.
The typical LSTM model for time series implementation in Python through Keras implementation appears as follows:
from keras.models import Sequential
from keras.layers import LSTM, Dense
model = Sequential()
model.add(LSTM(units=50, input_shape=(timesteps, features)))
model.add(Dense(1)) # output layer
model.compile(loss='mse', optimizer='adam')
model.fit(X_train, y_train, epochs=20, batch_size=16)
The systems perform exceptionally well in time series prediction together with sequence forecasting. GRUs function as a basic LSTMs version which operates with reduced gates but maintains the sequence modeling method from the original design.
TCN represents a modern method which employs 1D convolutional processing to handle sequential data. The implementation process requires designers to create multiple convolutional layers, which use dilation, to achieve simultaneous modeling of extended time-related patterns. TCNs have been shown to match or exceed RNN performance on many sequence tasks.
| Aspect | Time Series Models | Standard ML Models |
| Data Structure | Ordered/Temporal: Data are indexed by time, with an implicit sequence. Each observation’s position matters (e.g. yesterday vs today). | Unordered/Independent: Samples are assumed i.d., with no inherent order. The model treats each row independently. |
| Feature Engineering | Lag Features & Windows: Create features from past values (e.g. t-1, t-2 lags, rolling averages). The data might be transformed into a sliding window of past observations. | Static Features: Use existing attributes or transformations (scaling, encoding, etc.) that do not depend on a time index. No need for sliding windows by default. |
| Time Assumptions | Temporal Dependency: Assumes autocorrelation (past influences future). Models capture trends/seasonality. | Independence: Assumes samples are independent. Time is either irrelevant or included only as a feature. No built-in notion of temporal sequence. |
| Training/Validation | Time-based Splits: Must respect chronology. Use a chronological or walk-forward split to avoid peeking into the future. | Random Splits (K-fold): Commonly uses random train/test splitting or k-fold cross-validation, which shuffles data. |
| Common Use Cases | Forecasting, trend analysis, anomaly detection in sequential data (sales over time, weather, finance). | Classification/regression on static or non-sequential data (image recognition, sentiment analysis, tabular predictions like credit scoring). |
In many real problems, you might even try both: for example, forecast with ARIMA or use XGBoost on lags and compare. The method which maintains data organization while effectively capturing signals should be selected.
Standard machine learning and time series analysis operate with different data structures and different fundamental assumptions. The time series methods use time as an essential variable to analyze temporal relationships and track trends and seasonal patterns. The appropriate time series models should be applied when your data follows a sequence, and you want to predict or analyze time-based patterns.
But the main point is that your objective and available information should guide your decision-making process. The appropriate time series method should be used when your goal requires you to forecast or analyze trends in your time-ordered data.
The standard ML approach should be used for your task when you need to perform typical classification and regression tasks that require testing on separate data samples.When you possess time series data but opt to use a standard ML model, you need to convert your data by creating lag features and establishing time periods. Time series models become unnecessary when your data remains fixed.
A. Time series models handle temporal dependencies, while standard ML assumes independent, unordered samples.
A. Yes. You can use them by creating lag features, rolling statistics, or sliding windows.
A. When your data is time-ordered and the goal involves forecasting, trend analysis, or sequential pattern learning.