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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:

  • Vector
  • Dataframe
  • Matrix
  • CSV
See all covered skills

9 reasons why
9 reasons why

Adaface R Online 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 expensive engineering time by filtering out unqualified candidates.

The Adaface R Online test screens candidates for the typical skills recruiters look for in an R programmer:

  • Strong programming experience and data management using SAS and R
  • Ability to work with large datasets
  • Ability to solve analytical problems using quantitative approaches
  • Experience with using machine learning methods and models

The insights generated from this assessment can be used by recruiters and hiring managers to identify the best candidates for the role. Anti-cheating features enable you to be comfortable with conducting assessments online. The R developer test is ideal for helping recruiters identify which candidates have the technical skills to do well on the job.

Reason #2

No trick questions

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.

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 ->
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.

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:
 image
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':
 image
Which of the following commands would turn it into the Dataframe shown below:
 image
 image

Medium

Matrix Manipulation
Matrices
Lists
Solve
Consider the following pseudo code:
 image
What will be the state of list_of_matrices after running the script?
 image

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

Medium

Dataframe Transform
3 mins
R
Solve

Medium

Matrix Manipulation
Matrices
Lists
3 mins
R
Solve

Easy

Registration Queue
Logic
Queues
30 mins
Coding
Solve

Medium

Visitors Count
Strings
Logic
30 mins
Coding
Solve
🧐 Question🔧 Skill💪 Difficulty⌛ Time
Applying Functions
Data frames
Functions
Math
R
Medium3 mins
Solve
Dataframe Transform
R
Medium3 mins
Solve
Matrix Manipulation
Matrices
Lists
R
Medium3 mins
Solve
Registration Queue
Logic
Queues
Coding
Easy30 minsSolve
Visitors Count
Strings
Logic
Coding
Medium30 minsSolve
Reason #4

1200+ customers in 75 countries

customers in 75 countries
Brandon

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

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.

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.

invite candidates
Reason #7

Detailed scorecards & benchmarks

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.

test completion rate
Reason #9

Advanced Proctoring


About The R Developer Role

R is an open-source programming language that is widely used among statisticians for developing statistical software, data analysis, and scientific research. R is not the only language that can be used for statistical computing. Some of the popular alternatives of R programming include Python, SAS (Statistical Analysis System), and SPSS (Software Package for Statistical Analysis).

Typical R programmer responsibilities include:

  • Designing and developing technical architecture, requirements, and statistical models
  • Supporting the technical team in the development of automated processes for data extraction and analysis
  • Preparing the codebase with scripts to ensure proper data access, manipulation, and reporting functions with R programming languages
  • Supporting users by developing documentation and assistance tools

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

What topics are covered in the R Online Test?

Analytics with R & tools
Introduction to Statistics
Data Manipulation using R
Machine Learning Techniques using R
Exploratory Data Analysis
Regression Analysis
Data Science Basics
String Manipulation
Vector
Matrix
Dataframe
CSV
Rmarkdown
linear regression

A confusion matrix can be used to evaluate the accuracy of the model built.

confusion matrix
Random Forest
Analytics with R & tools
package
R6 Class
shinyR

The apply function allows one to make entry-by-entry changes to data frames and matrices.

apply function
Clustering
kmeans clustering
hierarchical clustering

Rattle is a popular GUI for data mining using R.

rattle
White Noise model

Principal Component Analysis is a method for dimensionality reduction.

Principal Component Analysis

initialize() function is used to initialize the private data members while declaring the object.

initialize()
evaluate_model()
Predictive Mean Matching
preloaded datasets
next
custom function
by()
factor variable
Radix
R decision tree
Data import
Singapore government logo

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

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.

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
  • Web proctoring
  • Webcam proctoring
  • Plagiarism detection
  • Secure browser

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.

I'm a candidate. Can I try a practice test?

No. Unfortunately, we do not support practice tests at the moment. However, you can use our sample questions for practice.

What is the cost of using this test?

You can check out our pricing plans.

Can I get a free trial?

Yes, you can sign up for free and preview this test.

I just moved to a paid plan. How can I request a custom assessment?

Here is a quick guide on how to request a custom assessment on Adaface.

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