Why you should use R Online Test?

The R Online Test makes use of scenario-based questions to test for on-the-job skills as opposed to theoretical knowledge, ensuring that candidates who do well on this screening test have the relavant skills. The questions are designed to covered following on-the-job aspects: Working with Vectors Performing operations on Matrices Analyzing Dataframes Importing and exporting CSV files Implementing Linear regression models Interpreting Confusion matrices Applying Random Forest algorithms Utilizing Analytics techniques Performing String Manipulation

R Online Test

Q: What topics are covered in the R Online Test?

Vectors Matrices Dataframes CSV Handling Linear regression Confusion matrix Random Forest Analytics with R String Manipulation

About the test:

The R Online Test uses scenario-based MCQs to evaluate candidates on their knowledge of R programming language, including their proficiency in working with data structures, control structures, functions, and data visualization using R libraries like ggplot2. The test includes a coding question to evaluate hands-on R programming skills and aims to evaluate a candidate's ability to work with R effectively for data analysis and statistical modeling.

Covered skills:

Vectors
Dataframes
Linear regression
Random Forest
String Manipulation

Matrices
CSV Handling
Confusion matrix
Analytics with R

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9 reasons why

Adaface R Test is the most accurate way to shortlist Data Scientists

Reason #1

Tests for on-the-job skills

The R Online Test helps recruiters and hiring managers identify qualified candidates from a pool of resumes, and helps in taking objective hiring decisions. It reduces the administrative overhead of interviewing too many candidates and saves time by filtering out unqualified candidates at the first step of the hiring process.

The test screens for the following skills that hiring managers look for in candidates:

Efficiently working with vectors
Working with matrices for data manipulation
Handling and analyzing data using dataframes
Managing CSV files and data handling
Applying linear regression models in R
Understanding and utilizing confusion matrices
Implementing random forest algorithms in R
Performing analytics tasks using R
Manipulating and transforming strings in R

Reason #2

No trick questions

Traditional assessment tools use trick questions and puzzles for the screening, which creates a lot of frustration among candidates about having to go through irrelevant screening assessments.

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The main reason we started Adaface is that traditional pre-employment assessment platforms are not a fair way for companies to evaluate candidates. At Adaface, our mission is to help companies find great candidates by assessing on-the-job skills required for a role.

Why we started Adaface

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Reason #3

Non-googleable questions

We have a very high focus on the quality of questions that test for on-the-job skills. Every question is non-googleable and we have a very high bar for the level of subject matter experts we onboard to create these questions. We have crawlers to check if any of the questions are leaked online. If/ when a question gets leaked, we get an alert. We change the question for you & let you know.

How we design questions

These are just a small sample from our library of 10,000+ questions. The actual questions on this R Online Test will be non-googleable.

🧐 Question
Medium Applying Functions Data frames Functions Math	Solve
Consider the following R code: This script defines a function apply_fun that calculates the mean of a vector and adds it to the standard deviation of the vector. The apply function is then used to apply this function to each column of the data frame df. What will be the value of result after the script is run?
Medium Dataframe Transform	Solve
Review the following Dataframe 'bazinga': Which of the following commands would turn it into the Dataframe shown below:
Medium Matrix Manipulation Matrices Lists	Solve
Consider the following pseudo code: What will be the state of list_of_matrices after running the script?
Easy Registration Queue Logic Queues	Solve
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount. For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition. ⚠️⚠️⚠️ Note: - The first line of the input is the length of the array. The second line contains all the elements of the array. - The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function. - You need to "print" the final result (not return it) to pass the test cases. For the example discussed above, the input will be: 5 20 70 -40 30 -10 Your code needs to print the following to the standard output: 20 70 30 -40 -10
Medium Visitors Count Strings Logic	Solve
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. Example: Input: WWMMWWCCC Expected Output: 4W3C2M Explanation: ‘W’ has the highest count, then ‘C’, then ‘M’. ⚠️⚠️⚠️ Note: - The input is already parsed and passed to a function. - You need to "print" the final result (not return it) to pass the test cases. - If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’. - If any of them have the same count, the output should follow this order - M, W, C.

	🧐 Question	🔧 Skill
	Medium Applying Functions Data frames Functions Math	3 mins R	Solve
Consider the following R code: This script defines a function apply_fun that calculates the mean of a vector and adds it to the standard deviation of the vector. The apply function is then used to apply this function to each column of the data frame df. What will be the value of result after the script is run?
	Medium Dataframe Transform	3 mins R	Solve
Review the following Dataframe 'bazinga': Which of the following commands would turn it into the Dataframe shown below:
	Medium Matrix Manipulation Matrices Lists	3 mins R	Solve
Consider the following pseudo code: What will be the state of list_of_matrices after running the script?
	Easy Registration Queue Logic Queues	30 mins Coding	Solve
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount. For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition. ⚠️⚠️⚠️ Note: - The first line of the input is the length of the array. The second line contains all the elements of the array. - The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function. - You need to "print" the final result (not return it) to pass the test cases. For the example discussed above, the input will be: 5 20 70 -40 30 -10 Your code needs to print the following to the standard output: 20 70 30 -40 -10
	Medium Visitors Count Strings Logic	30 mins Coding	Solve
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. Example: Input: WWMMWWCCC Expected Output: 4W3C2M Explanation: ‘W’ has the highest count, then ‘C’, then ‘M’. ⚠️⚠️⚠️ Note: - The input is already parsed and passed to a function. - You need to "print" the final result (not return it) to pass the test cases. - If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’. - If any of them have the same count, the output should follow this order - M, W, C.

	🧐 Question	🔧 Skill	💪 Difficulty	⌛ Time
	Applying Functions Data frames Functions Math	R	Medium	3 mins	Solve
Consider the following R code: This script defines a function apply_fun that calculates the mean of a vector and adds it to the standard deviation of the vector. The apply function is then used to apply this function to each column of the data frame df. What will be the value of result after the script is run?
	Dataframe Transform	R	Medium	3 mins	Solve
Review the following Dataframe 'bazinga': Which of the following commands would turn it into the Dataframe shown below:
	Matrix Manipulation Matrices Lists	R	Medium	3 mins	Solve
Consider the following pseudo code: What will be the state of list_of_matrices after running the script?
	Registration Queue Logic Queues	Coding	Easy	30 mins	Solve
We want to register students for the next semester. All students have a receipt which shows the amount pending for the previous semester. A positive amount (or zero) represents that the student has paid extra fees, and a negative amount represents that they have pending fees to be paid. The students are in a queue for the registration. We want to arrange the students in a way such that the students who have a positive amount on the receipt get registered first as compared to the students who have a negative amount. We are given a queue in the form of an array containing the pending amount. For example, if the initial queue is [20, 70, -40, 30, -10], then the final queue will be [20, 70, 30, -40, -10]. Note that the sequence of students should not be changed while arranging them unless required to meet the condition. ⚠️⚠️⚠️ Note: - The first line of the input is the length of the array. The second line contains all the elements of the array. - The input is already parsed into an array of "strings" and passed to a function. You will need to convert string to integer/number type inside the function. - You need to "print" the final result (not return it) to pass the test cases. For the example discussed above, the input will be: 5 20 70 -40 30 -10 Your code needs to print the following to the standard output: 20 70 30 -40 -10
	Visitors Count Strings Logic	Coding	Medium	30 mins	Solve
A manager hires a staff member to keep a record of the number of men, women, and children visiting the museum daily. The staff will note W if any women visit, M for men, and C for children. You need to write code that takes the string that represents the visits and prints the count of men, woman and children. The sequencing should be in decreasing order. Example: Input: WWMMWWCCC Expected Output: 4W3C2M Explanation: ‘W’ has the highest count, then ‘C’, then ‘M’. ⚠️⚠️⚠️ Note: - The input is already parsed and passed to a function. - You need to "print" the final result (not return it) to pass the test cases. - If the input is- “MMW”, then the expected output is "2M1W" since there is no ‘C’. - If any of them have the same count, the output should follow this order - M, W, C.

Reason #4

1200+ customers in 75 countries

With Adaface, we were able to optimise our initial screening process by upwards of 75%, freeing up precious time for both hiring managers and our talent acquisition team alike!

Brandon Lee, Head of People, Love, Bonito

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Reason #5

Designed for elimination, not selection

The most important thing while implementing the pre-employment R Online Test in your hiring process is that it is an elimination tool, not a selection tool. In other words: you want to use the test to eliminate the candidates who do poorly on the test, not to select the candidates who come out at the top. While they are super valuable, pre-employment tests do not paint the entire picture of a candidate’s abilities, knowledge, and motivations. Multiple easy questions are more predictive of a candidate's ability than fewer hard questions. Harder questions are often "trick" based questions, which do not provide any meaningful signal about the candidate's skillset.

Science behind Adaface tests

Reason #6

1 click candidate invites

Email invites: You can send candidates an email invite to the R Online Test from your dashboard by entering their email address.

Public link: You can create a public link for each test that you can share with candidates.

API or integrations: You can invite candidates directly from your ATS by using our pre-built integrations with popular ATS systems or building a custom integration with your in-house ATS.

Reason #7

Detailed scorecards & benchmarks

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Reason #8

High completion rate

Adaface tests are conversational, low-stress, and take just 25-40 mins to complete.

This is why Adaface has the highest test-completion rate (86%), which is more than 2x better than traditional assessments.

Reason #9

Advanced Proctoring

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About the R Assessment Test

Why you should use Pre-employment R Online Test?

The R Online Test makes use of scenario-based questions to test for on-the-job skills as opposed to theoretical knowledge, ensuring that candidates who do well on this screening test have the relavant skills. The questions are designed to covered following on-the-job aspects:

Working with Vectors
Performing operations on Matrices
Analyzing Dataframes
Importing and exporting CSV files
Implementing Linear regression models
Interpreting Confusion matrices
Applying Random Forest algorithms
Utilizing Analytics techniques
Performing String Manipulation

Once the test is sent to a candidate, the candidate receives a link in email to take the test. For each candidate, you will receive a detailed report with skills breakdown and benchmarks to shortlist the top candidates from your pool.

What topics are covered in the R Online Test?

Vectors
Vectors in R are one-dimensional arrays that can hold elements of any type. They are used to store and perform operations on a homogeneous set of data. Measuring this skill will assess a candidate's understanding of vector creation, indexing, and various vector operations.
Matrices
Matrices in R are two-dimensional arrays that store elements of the same type. This skill will evaluate a candidate's ability to create and manipulate matrices, perform matrix operations such as addition, subtraction, and multiplication, and apply matrix operations in solving problems.
Dataframes
Dataframes are tabular data structures in R that store data in rows and columns. Assessing a candidate's knowledge of dataframes will ascertain their proficiency in data manipulation, including merging, filtering, and transforming data, as well as their understanding of data reshaping.
CSV Handling
CSV (Comma-Separated Values) handling is the ability to read, write, and manipulate data stored in CSV format. This skill is crucial in real-life scenarios where data is often exchanged and stored in CSV files. Assessing this skill will determine a candidate's proficiency in loading, saving, and performing data transformations on CSV files in R.
Linear regression
Linear regression is a statistical technique used to analyze the relationship between a dependent variable and one or more independent variables. Measuring a candidate's understanding of linear regression will assess their ability to fit linear regression models, interpret model outputs, and make predictions using the models.
Confusion matrix
A confusion matrix is a table that represents the performance of a classification algorithm. Measuring a candidate's knowledge of confusion matrices will evaluate their understanding of key metrics such as accuracy, precision, recall, and F1 score, and their ability to analyze and interpret classification results.
Random Forest
Random Forest is an ensemble learning method used for classification and regression. Assessing this skill will gauge a candidate's ability to apply the Random Forest algorithm, understand the underlying principles, tune the model parameters, and evaluate its performance using appropriate statistical measures.
Analytics with R
Analytics with R involves using R programming language and its associated packages to perform data analysis, visualization, and statistical modeling. Evaluating this skill will determine a candidate's proficiency in utilizing R's analytical capabilities, applying statistical techniques, and generating insights from data.
String Manipulation
String manipulation refers to the process of modifying, extracting, or manipulating textual data in R. This skill assessment will measure a candidate's ability to perform tasks such as concatenating strings, replacing patterns, extracting substrings, and applying regular expressions on character data to solve data processing and manipulation challenges.
Full list of covered topics
The actual topics of the questions in the final test will depend on your job description and requirements. However, here's a list of topics you can expect the questions for R Online Test to be based on.
Vectors
Matrices
Dataframes
CSV Handling
Linear Regression
Confusion Matrix
Random Forest
Analytics with R
String Manipulation
Vector Operations
Matrix Operations
Dataframe Manipulation
Reading and Writing CSV Files
Simple Linear Regression
Multiple Linear Regression
Interpreting Confusion Matrices
Random Forest Algorithm
Classification and Regression Trees (CART)
Clustering Algorithms
Data Exploration and Visualization
Data Cleaning and Preprocessing
Statistical Analysis in R
Text Manipulation and Extraction
Regular Expressions
String Matching
Missing Data Handling
Data Aggregation and Reshaping
Handling Time Series Data
Dimensionality Reduction Techniques
Statistical Modeling Techniques in R
Handling Outliers and Anomalies
Data Mining and Machine Learning
Feature Selection and Variable Importance
Model Evaluation and Validation
Performance Measurement Metrics
Cross-Validation Techniques
Hyperparameter Tuning
Data Imputation Techniques
Web Scraping and APIs in R
Databases and SQL Integration in R
Geospatial Analysis and Mapping
Data Visualization with ggplot2
Statistical Tests and Hypothesis Testing
Time Series Forecasting
Natural Language Processing (NLP)
Image Processing and Computer Vision
Big Data Analytics with R
Deep Learning and Neural Networks
Parallel Computing and Performance Optimization
R Shiny App Development
Reproducible Research with R Markdown
Version Control with Git and GitHub
Collaborative Data Science with RStudio
Scalable Analytics using SparkR
Cloud Computing and R Integration
Creating Interactive Dashboards with Shiny
Advanced Data Visualization Techniques
Graph Analysis and Social Network Data
Bayesian Statistics and Inference in R

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What roles can I use the R Online Test for?

Data Scientist
Data Analyst
Core R Developer
Core R Programmer
Python Developer
Machine Learning Engineer

How is the R Online Test customized for senior candidates?

For intermediate/ experienced candidates, we customize the assessment questions to include advanced topics and increase the difficulty level of the questions. This might include adding questions on topics like

Mastering data visualization
Implementing machine learning algorithms
Applying data mining techniques
Working with time series data
Performing data cleaning and preprocessing
Understanding statistical inference
Applying optimization techniques
Applying natural language processing
Utilizing parallel computing

The coding question for experienced candidates will be of a higher difficulty level to evaluate more hands-on experience.

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The hiring managers felt that through the technical questions that they asked during the panel interviews, they were able to tell which candidates had better scores, and differentiated with those who did not score as well. They are highly satisfied with the quality of candidates shortlisted with the Adaface screening.

85%

reduction in screening time

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R Hiring Test FAQs

Can I combine multiple skills into one custom assessment?

Yes, absolutely. Custom assessments are set up based on your job description, and will include questions on all must-have skills you specify. Here's a quick guide on how you can request a custom test.

Do you have any anti-cheating or proctoring features in place?

We have the following anti-cheating features in place:

Non-googleable questions
IP proctoring
Screen proctoring
Web proctoring
Webcam proctoring
Plagiarism detection
Secure browser
Copy paste protection

Read more about the proctoring features.

How do I interpret test scores?

The primary thing to keep in mind is that an assessment is an elimination tool, not a selection tool. A skills assessment is optimized to help you eliminate candidates who are not technically qualified for the role, it is not optimized to help you find the best candidate for the role. So the ideal way to use an assessment is to decide a threshold score (typically 55%, we help you benchmark) and invite all candidates who score above the threshold for the next rounds of interview.

What experience level can I use this test for?

Each Adaface assessment is customized to your job description/ ideal candidate persona (our subject matter experts will pick the right questions for your assessment from our library of 10000+ questions). This assessment can be customized for any experience level.

Does every candidate get the same questions?

Yes, it makes it much easier for you to compare candidates. Options for MCQ questions and the order of questions are randomized. We have anti-cheating/ proctoring features in place. In our enterprise plan, we also have the option to create multiple versions of the same assessment with questions of similar difficulty levels.