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Learner Reviews & Feedback for Getting and Cleaning Data by Johns Hopkins University

8,048 ratings

About the Course

Before you can work with data you have to get some. This course will cover the basic ways that data can be obtained. The course will cover obtaining data from the web, from APIs, from databases and from colleagues in various formats. It will also cover the basics of data cleaning and how to make data “tidy”. Tidy data dramatically speed downstream data analysis tasks. The course will also cover the components of a complete data set including raw data, processing instructions, codebooks, and processed data. The course will cover the basics needed for collecting, cleaning, and sharing data....

Top reviews


May 2, 2020

This course provides an introduction of some important concepts and tools on a very important aspect of data science: cleaning and organizing data before any analysis. A must for any data scientist.


Oct 25, 2016

This course is really a challenging and compulsory for any one who wants to be a data scientist or working in any sort of data. It teaches you how to make very palatable data-set fro ma messy data.

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1251 - 1275 of 1,307 Reviews for Getting and Cleaning Data

By Adam M

Jan 17, 2020

The information in the lectures is very stale, which makes it extremely frustrating to learn from.


Mar 10, 2021

Messier than the 2 previous courses. Lacks explanations for codebook in the peer-graded exam.

By Sudarshan P

Dec 5, 2017

The course material needs update. There are code snippets that do not work.

By Aditya D

Sep 18, 2017

This course could have been better. It was all textual and it got boring.

By James C

May 29, 2017

Final assignment is not well detailed, and may cause confusion.

By Guy P

Mar 3, 2016

This course lacks projects to implement the skills we learn.

By Lee D

May 18, 2016

The course was a bit mixed in terms of its quality.

By Colin H

Oct 21, 2020

Guidance for assessments could be a lot better

By Adam K

Aug 25, 2019

Very poor instructions for assignments.

By Rafee S

Feb 25, 2019

waste of time for software engineers

By Maximilian P

Jul 11, 2018

Too many things in one place

By Sergio B

Nov 17, 2017

Worst class in this series.

By Michal K

Apr 29, 2016

too superficial

By Leandro J G D

May 12, 2020

Lacking focus.

By Warren

Aug 5, 2016


By Walson Q

Nov 29, 2018


By Dan H

Jan 16, 2018

This course is about getting data from the web and processing it using a computer language and packages in that language that are under active development. There is a github repo with course content and other electronic resources that are made to be easy to update. It has never been updated, even once since the course first went live 4 years ago. There are many broken links, several new features and bugs in packages that make lecture content obsolete or broken, errors found by students, etc. None of these issues have been addressed, even once, in any of the material, including the extremely easy to update content on github. This is disappointing and not very professional. Additionally, many of the notes are not particularly good to begin with. Much of it is essentially cribbed from other online tutorials, examples in the documentation, and in a few cases, someone else's (also broken) lectures. Take this course if you want a study group (the forums are actually quite useful) to help you go through 4 year old lectures rehashing online tutorials from 4 years ago about a topic that changes pretty quickly.

By Grant I

Jan 22, 2018

Made it all the way to week four and decided to drop this entire specialization. The data set in the final project is poorly referenced (despite the code book provided). The data set comes in 24 text files you have to merge (which isn't a problem in R) but what is a problem is when you don't understand what the variables and observations are. Perhaps if I worked in the medical field these measurements would mean more, but to a business major, they are incomprehensible with the limited documentation provided. So my assumption was, if I am having difficulty understanding what the final data structure should look like, others will be having the same problem......and its peer reviewed. How can I possible grade someone else

By Abdulaziz M A A

Jul 2, 2020

I have to date completed the first 2 courses in Data Science: Foundations using R Specialization.

Today I have cancelled my subscription for the following reasons:

1 Poor course design and delivery

Lesson contents inadequately covered and sourced, lecturers deliver a fast paced recordings with very little examples and references making it hard for beginner students to keep pace and find themselves unprepared for the required quizzes and exams.

2 Course materials needs to be updated and presented to facilitate learning , eg. often times students are referred to static links and too many many times new and un-familiar concepts/ functions are rushed thru with no introduction or explanation.

By Ryan N

Oct 29, 2021

Course content is ok except for the week 2, quite confusing. Not very detail. Quite a few slides asking you to read up yourself from other sources.

And for the quizzes, mostly beyond the scope of the course.

Project wise, coding part is fine. The part that is totally not fine is the project requires you to prepare codebook and README, without any guidance in any videos in this course, or courses prior to taking this course. All you need is to read up yourself from other sources. The community are assuming people who are taking these courses have good knowledge in programming related work.

By Apurva G

Mar 30, 2020

Its extremely difficult to install the packages. Most of the time the instructions are not clear on what packages to intall in the videos. There should be a pre-read with links and instructions on which packages are needed to be able to work on this course. Extremely frustrating, considering a majority of the time is wasted just trying to figure out how to install packages. If you are serious about success of course takers, you have to make it easier to understand and instructions have to be clear.

By Andrés P

Jun 22, 2022

I received my certificate and it states the following:

"This certificate does not af_rm that this learner was enrolled as a student at Johns Hopkins University. It does not confer a JHU grade, course credit or degree; establish a relationship between this learner and JHU; enroll or register this learner at JHU or in any course offered by JHU; or entitle this learner to access or use resources beyond the online courses provided by Coursera."

Does this mean has no validation?

By Zdeněk Š

Aug 27, 2022

The peer review is very frustrating. Sometimes the peers appear to not understand the assignment and you cant contest the decision. Many reviewers write only "you can do better" as they give you low scoring, with no further explanation of whats wrong.

The information taught in this course is equivalent to a couple of tutorials you can find online for free, paying for this is a waste of money. Sadly, having certificates looks good, even if they mean nothing.

By Deleted A

Jan 13, 2017

For such a terrible course to then change payment terms without my authorisation. Take $64 from my account without telling me clearly amongst all the other junk mail. Coursera have a lot to answer for, and this specialisation is not even worth wasting your time if it was free.

Taught without purpose; meaningless instructions given to copy without regard of the bigger picture.

By Quoc N

Feb 18, 2018

First quiz states 10 minutes for a 5 question quiz. I am taking way longer due to errors in loading packages and Java. One of the question is out of date and has not been updated in a year. Quality of this course is lacking when changes are constant. The mentors say it's realistic. I'd considering dropping this course and search for a better updated one.