If you followed through the Basic Decision Tree exercise, this should be useful for you. This is like a continuation but we add so much more. We are working with a bigger and badder datasets. We will be also using techniques we learned from model evaluation and work with ROC, accuracy and other metrics. Answers […]

# statistics

## Model Evaluation 2

We are committed to bringing you 100% authentic exercise sets. We even try to include as different datasets as possible to give you an understanding of different problems. No more classifying Titanic dataset. R has tons of datasets in its library. This is to encourage you to try as many datasets as possible. We will […]

## Basic Tree 2 Exercises

This is a continuation of the exercise Basic Tree 1 Answers to the exercises are available here. If you obtained a different (correct) answer than those listed on the solutions page, please feel free to post your answer as a comment on that page. Exercise 1 load the tree library. If it is not installed […]

## Recursive Partitioning and Regression Trees Exercises

[For this exercise, we will work using the package rpart. This is a beginner level exercise. Please refer to the help of rpart package] Answers to the exercises are available here. Exercise 1 Consider the Kyphosis data frame(type help(‘kyphosis’) for more details), that contains: -Kyphosis:a factor with levels absent present indicating if a kyphosis (a […]

## Basic Tree 1 Exercises

Using the knowledge you acquired in the previous exercises on sampling and selecting(here), we will now go through an entire data analysis process. You will be using what you know as crutches to solve the problems. Don’t worry. It might look intimidating but follow the sequence and you will see that modeling a decision tree […]

## Model Evaluation Exercises 1

We are committed to bringing you 100% authentic exercise sets. We even try to include as different datasets as possible to give you an understanding of different problems. No more classifying Titanic dataset. R has tons of datasets in its library. This is to encourage you to try as many datasets as possible. We will […]

## Frequency and chi-square test for independence Exercises

In this exercise, we cover some basics on frequency tables. We also briefly look at chi-square test for independence to find relationships of two variables. Before proceeding, it might be helpful to look over the help pages for the table, summary, and margin.table functions. Answers to the exercises are available here. If you obtained a […]

## Repeated measures ANOVA in R Exercises

One way, two way and n way ANOVA are used to test difference in means when we have one, two and n factor variables. A key assumption when performing these ANOVAs is that the measurements are independent. When we have repeated measures this assumption is violated, so we have to use repeated measures ANOVA. Repeated […]

## Nonparametric Tests Exercises

In this set of exercises you will be presented with real-life problems in marketing. Your task will be to choose appropriate nonparametric statistical technique and solve the problem using appropriate R functions. Answers to the exercises are available here. Exercise 1 A company wants to learn if sales income is equaly distributed among the stores. […]

## Two Way ANOVA in R Exercises

One way analysis of variance helps us understand the relationship between one continuous dependent variable and one categorical independent variable. When we have one continuous dependent variable and more than one independent categorical variable we cannot use one way ANOVA. When we have two independent categorical variable we need to use two way ANOVA. When […]