Introduction
In preparing data for analysis, it’s important to keep your data clean and ready for analysis. If you want to get the most out of your data science project, it’s critical that you create datasets that are well-prepared. Otherwise, even if your model has high accuracy on training sets it may not generalize well in production because there was a problem during the preparation phase which caused bias or variance error
Dataset Preparation
Dataset preparation is the process of preparing data for analysis. A dataset must be prepared before it can be analyzed, and this step is critical to your success as a data scientist. It’s also an important part of the overall process, but it should not be your only focus.
The best way to think about dataset preparation is as an iterative process: you’ll start by getting some basic information about your source data, then clean up any issues you find along the way before finally moving on to more advanced processing techniques like feature engineering and model building.
How To Avoid Common Data Preparation Mistakes
Data preparation is a critical step in the analytics process. It’s not just about getting your data into a certain format, but also making sure it’s ready for analysis.
If you’re planning on using AI or machine learning to analyze your data, then make sure you’ve done all of this before moving forward:
- Ensure that your data includes only relevant information (i.e., no missing values).
- Make sure there aren’t any duplicate records or rows that shouldn’t be there. This can happen when multiple users enter the same information multiple times into different columns of your spreadsheet–for example, if two salespeople both record the same customer order on separate orders sheets and then upload them into one master file later on).
Data Preparation Strategies
- Identify the data you need.
- Find the right data sources.
- Collect the data in a consistent format.
- Clean, transform and prepare your dataset for analysis!
Concatenation
Concatenation is the process of combining two or more datasets into a single dataset. It is typically done to combine data sets of different types, such as combining a text file with a numerical file. In this tutorial, we will use the R programming language to concatenate two datasets into one.
The first step is loading both of our datasets into R and making sure they are in the correct format:
Data cleansing and standardization
In this section, we’re going to discuss how to clean and standardize your data. Data cleansing refers to the process of removing any unnecessary information from a dataset while standardization involves transforming variables so that they have consistent units or values across all observations.
Standardizing can be useful because it allows us to compare variables on a common scale (i.e., an increase in salary doesn’t mean much if it’s measured in dollars or pennies). For example, if we have two variables related to income–income1 and income2–and want them both measured in thousands of dollars per year, then we’ll need some way of converting income1 into thousands as well..
Feature engineering, transformation and normalization.
Feature engineering and transformation are two procedures that can be used to reduce the dimensionality of your data, as well as reduce noise and bias. This is done by transforming your features into new ones that are more meaningful or easier to analyze.
For example, if you were working with a dataset containing user ratings for movies on Netflix, you might want to transform each rating into its corresponding number of stars so that they’re easier for machines (and humans) to understand: 1 star = poor; 2 stars = okay; 3 stars = good; 4 stars = great!
After transforming each feature into something more understandable and usable by computers, we then need to normalize our transformed column(s). Normalization involves subtracting out any mean values from each column so that all columns have zero mean value across all rows – this helps ensure consistency among columns when doing computations later on in machine learning algorithms like gradient boosting trees or neural networks.
Pre-processing & Feature Engineering.
Data preprocessing is a series of data cleaning and transformation steps that are applied to raw data. It’s required before you can do any sort of meaningful analysis, so it’s important to understand what this process entails.
Data preprocessing involves a lot of data cleaning and transformation–most commonly:
- Removing missing values from your dataset (if any)
- Categorical variables must be converted into numerical form (e.g., convert “Yes” or “No” answers into 1s and 0s)
- You may have multiple variables with the same name but different meanings (e.g., height in centimeters vs height in inches). You’ll need to rename these columns so they don’t clash when merged together later
It’s important to keep your data clean and ready for analysis.
At this point, you should have a clean dataset that’s ready for analysis. It’s important to keep your data clean and ready for analysis.
The first step in preparing a dataset is importing the data into R. You can do this by opening up RStudio and clicking on “File > Open” or using an online service like [DataHero](https://www.datahorizon.com/). Once you’re in RStudio, navigate to where your files are located on your computer (if they aren’t already there) and select them from under “Files.” If they are located within another folder somewhere else on your computer, then open up the folder containing those files rather than just selecting them from inside of another folder named “Files.” Next click on Tools > Data Import Wizard > Next Step: Select Your Data Source! This will bring up an interface allowing us access to different sources for our analysis; we’ll cover more about choosing what source later in this tutorial series!
Conclusion
We hope this tutorial has given you a better understanding of data preparation and preprocessing. It’s an important part of any analysis, and can be challenging for even experienced analysts. If you’d like to learn more about how we can help with your data preparation needs, please contact us today!
