# Author Archives: Ajitesh Kumar

## Difference between Data Science & Data Analytics

What’s the difference between data science and data analytics? Many people use these terms interchangeably, but there is a big distinction between the two fields. Data science is more focused on understanding and deriving insights from data while leveraging statistical and machine learning methods, while data analytics is an overarching term used to solve problems using analytical techniques while leveraging data. Both the terms are in a way related. In this blog post, we’ll explore the differences between data science and data analytics in greater detail, with examples of each. The following are key topics in relation to the difference between data science and data analytics: Different forms/purposes Different techniques …

## Top US Universities for AI / ML Research

Artificial Intelligence (AI) has become an essential driver of innovation and economic growth in the 21st century. As a result, some of the best universities in the United States have been investing heavily in AI research to push the boundaries of this rapidly evolving field. In this blog post, we will explore the top 10 US universities for AI research, highlighting their achievements and providing links to their AI research homepages. Several leading / best universities in the United States have emerged as pioneers in AI research, recognizing its crucial role in driving innovation and economic growth. These institutions have made significant investments to establish themselves as top destinations for …

## Linear Regression T-test: Formula, Example

Linear regression is a popular statistical method used to model the relationship between a dependent variable and one or more independent variables. In linear regression, the t-test is a statistical hypothesis testing technique that is used to test the hypothesis related to linearity of the relationship between the response variable and different predictor variables. In this blog, we will discuss linear regression and t-test and related formulas and examples. For a detailed read on linear regression, check out my related blog – Linear regression explained with real-life examples. T-tests are used in linear regression to determine if a particular variable is statistically significant in the model. A statistically significant variable …

## When to Use Z-test vs T-test: Differences, Examples

When it comes to statistical tests, z-test and t-test are two of the most commonly used. But what is the difference between z-test and t-test? And when should you use Z-test vs T-test? In this blog post, we will answer all these questions and more! We will start by explaining the difference between z-test and t-test in terms of their formulas. Then we will go over some examples so that you can see how each test is used in practice. As data scientists, it is important to understand the difference between z-test and t-test so that you can choose the right test for your data. Let’s get started! Difference between …

## Hold-out Method for Training Machine Learning Models

The hold-out method for training the machine learning models is a technique that involves splitting the data into different sets: one set for training, and other sets for validation and testing. The hold-out method is used to check how well a machine learning model will perform on the new data. In this post, you will learn about the hold-out method used during the process of training the machine learning model. Do check out my post on what is machine learning? concepts & examples for a detailed understanding of different aspects related to the basics of machine learning. Also, check out a related post on what is data science? When evaluating …

## How to Choose Right Statistical Tests: Examples

Whether you are a researcher, data analyst, or data scientist, selecting the appropriate statistical test is crucial for accurate and reliable data analysis. With numerous tests available, it can be overwhelming to determine the right one for your research question and data type. In this blog, the aim is to simplify the process, providing you with a systematic approach to choosing the right statistical test. This blog will be particularly helpful for those who are new to statistical analysis and are unsure which test to use for their specific needs. You will learn a clear and structured method for selecting the appropriate statistical test. By considering factors such as data …

## One-way ANOVA test: Concepts, Formula & Examples

The one-way analysis of variance (ANOVA) test is a statistical procedure commonly used to compare the means values on a specific variable between three or more groups. The significance of the difference between the means of two samples can be judged through either t-test or z-test depending upon different criteria, but it becomes tricky when there is a need to simultaneously evaluate the significance of the difference amongst three or more sample means. This is where one-way ANOVA test comes to rescue. The ANOVA technique enables us to perform this simultaneous test and as such is considered to be an important tool of analysis. As data scientists, it is of …

## Two samples Z-test for Means: Formula & Examples

Statistical hypothesis testing is an essential tool in inferential statistics that enables researchers to make informed decisions about the population parameters based on sample statistics. One common hypothesis test for comparing two sample means is the Two-Sample Z-Test. In statistics, a two-sample z-test for means is used to determine if the means of two populations are equal. This test is used when the population standard deviations are known. As data scientists, it is of utmost importance to be able to understand and conduct this test accurately. In this blog, we will delve deeper into the Two-Sample Z-Test for means, exploring its formula, assumptions, and examples of how to apply it …

## Two independent samples t-tests: Formula & Examples

As a data scientist, you may often come across scenarios where you need to compare the means of two independent samples. In such cases, a two independent samples t-test, also known as unpaired two samples t-test, is an essential statistical tool that can help you draw meaningful conclusions from your data. This test allows you to determine whether the difference between the means of two independent samples is statistically significant or due to chance. In this blog, we will cover the concept of two independent samples t-tests, its formula, real-world examples of its applications and the Python example (using scipy.stats.ttest_ind function). We will begin with an overview of what a …

## Neyman-Pearson Lemma: Hypothesis Test, Examples

Have you ever faced a crucial decision where you needed to rely on data to guide your choice? Whether it’s determining the effectiveness of a new medical treatment or assessing the quality of a manufacturing process, hypothesis testing becomes essential. That’s where the Neyman-Pearson Lemma steps in, offering a powerful framework for making informed decisions based on statistical evidence. The Neyman-Pearson Lemma holds immense importance when it comes to solving problems that demand decision making or conclusions to a higher accuracy. By understanding this concept, we learn to navigate the complexities of hypothesis testing, ensuring we make the best choices with greater confidence. In this blog post, we will explore …

## Pandas CSV to Dataframe Python Example

Converting CSV files to DataFrames is a common task in data analysis. In this blog, we’ll explore a Python code example using the Pandas library to efficiently convert CSV files to DataFrames. This approach offers flexibility, speed, and convenience, making it a valuable technique for handling large datasets. Read CSV into Pandas Dataframe The following is the code which can be used to read the CSV file from local drive: In case, you want to read CSV file from the URL, the following will be the code. As a matter of fact, nothing changes except for the fact that you pass the URL to read_csv function. The following are some …

## Pearson Correlation Coefficient: Formula, Examples

In the world of data science, understanding the relationship between variables is crucial for making informed decisions or building accurate machine learning models. Correlation is a fundamental statistical concept that measures the strength and direction of the relationship between two variables. However, without the right tools and knowledge, calculating correlation coefficients and p-values can be a daunting task for data scientists. This can lead to suboptimal decision-making, inaccurate predictions, and wasted time and resources. In this post, we will discuss what Pearson’s r represents, how it works mathematically (formula), its interpretation, statistical significance, and importance for making decisions in real-world applications such as business forecasting or medical diagnosis. We will …

## Demystifying Encoder Decoder Architecture & Neural Network

In the field of AI / machine learning, the encoder-decoder architecture is a widely-used framework for developing neural networks that can perform natural language processing (NLP) tasks such as language translation, etc which requires sequence to sequence modeling. This architecture involves a two-stage process where the input data is first encoded into a fixed-length numerical representation, which is then decoded to produce an output that matches the desired format. As a data scientist, understanding the encoder-decoder architecture and its underlying neural network principles is crucial for building sophisticated models that can handle complex data sets. By leveraging encoder-decoder neural network architecture, data scientists can design neural networks that can learn …

## Google Unveils Next-Gen LLM, PaLM-2

Google’s breakthrough research in machine learning and responsible AI has culminated in the development of their next-generation large language model (LLM), PaLM 2. This model represents a significant evolution in natural language processing (NLP) technology, with the capability to perform a broad array of advanced reasoning tasks, including code and math, text classification and question answering, language translation, and natural language generation. The unique combination of compute-optimal scaling, an improved dataset mixture, and model architecture enhancements is what powers PaLM 2’s exceptional capabilities. This combination allows the model to achieve superior performance than its predecessors, including the original PaLM, across all tasks. PaLM 2 was built with Google’s commitment to …

## Occam’s Razor in Machine Learning: Examples

“Everything should be made as simple as possible, but not simpler.” – Albert Einstein Consider this: According to a recent study by IDC, data scientists spend approximately 80% of their time cleaning and preparing data for analysis, leaving only 20% of their time for the actual tasks of analysis, modeling, and interpretation. Does this sound familiar to you? Are you frustrated by the amount of time you spend on complex data wrangling and model tuning, only to find that your machine learning model doesn’t generalize well to new data? As data scientists, we often find ourselves in a predicament. We strive for the highest accuracy and predictive power in our …

## Pandas Dataframe: How to Add Rows & Columns

Pandas is a popular data manipulation library in Python, widely used for data analysis and data science tasks. Pandas Dataframe is a two-dimensional labeled data structure with columns of potentially different types, similar to a spreadsheet or SQL table. One of the common tasks in data manipulation is adding new rows or columns to an existing dataframe. It might seem like a trivial task, but choosing the right method to add rows or columns can significantly impact the performance and efficiency of your code. In this blog, we will explore the different ways to add rows and columns to a Pandas Dataframe. We will look into different methods available in …

You can use citation styles as appropriate. Thank you Kumar, Ajitesh. "Two independent samples t-tests: Formula & Examples." Vitalflux.com, 22…