Basically impossible to complete quizzes and course project using the provided course material. Poor correlation between instruction and testing. Makes one wonder: If I need to solicit others' guidance to complete your tests, why am I paying for your guidance in the first place?

R is really just the worst, and the instructors do not make it better. The code in this class is unreadable:

- too many one liners, because "it's faster to write", though harder for other people to read

- variables are named cryptic things like spIns or x, rather than names with meaning (eg, sprays.by.insect), again "because it's faster to type"

- way too many cases of "there is more than one way to do it", which just makes things confusing because the other ways tend not to be equivalent

What I'm most concerned about is that I've seen lots of poorly written code in many different languages: Java, C++, C, Python, Perl, and now R. But I've also seen really well-written code in all the languages *but* R, I have yet to see any code in R that is flexible, maintainable, and clear. Which leads me to think that no such code exists, or it's so rare that it doesn't matter. It is clear to me that if I am to do data analysis, then I will need a different set of tools; but because this specialization is taught entirely around R (the lectures are about R, not about higher-level concepts), then this specialization is not useful to me.

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 One of the question is out of date and has not been updated in a year.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.

Terrible! Go to Data Camp and save a bunch of money!!!!

There are quite a few issues with the final assignment of the Getting and Cleaning Data course. I feel this assignments lacks quality in contents, suffers from a flawed process and lack of attention by the moderator.

lectures are too fast.dropping out.

Poorly constracted course!

Lectures and other material just don't cover the information needed in the course project. Majority of the learning has to be done outside of this course, in order to pass the course project.

I cannot recommend this course anyone who is not deeply familiar with the topic already. The course project is truly frustrating!

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.

all the practical things had to be learned by self learning instead of in the course. Peer graded assignment took for ever to pass

Poor teaching! Almost a waste of time.

This is just because of the unclarity of the final assignment.

Description of assignment questions is not clear. The expected answer from the questions are confusing.

final project is terribly defined. Lecturers, Coursera, and Johns Hopkins should all be ashamed.

Very scattered and unfocused course. Sad to say that I learned very little from this one.

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

Expected more explanation with the teaching part, detailed lecture depicting live examples is needed to explain each and every module of the course. similar examples like Assignments can be taught by hard-coding them with RStudio

hoping that these things can change with the next courses which I'm enrolling

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.

Why are people writing extensive blog posts contemplating the vague wording of the final assignment when you could just *fix the assignment*? Also, one of the worst explanations of regular expressions I've ever heard.

MUito rápido o conteúdo e o fato do suporte ser somente o fórum deixa o curso vago, achei muito fraco os slides e o método de ensino.

Poderiam focar mais em exercícios e nos comandos mais difíceis, pois quando chega nos assignments fiquei perdido por não ter conseguido realizar da forma esperada.

the learning way in this course was bad, to me

No idea what they want for the project and the discussion forum is clogged with people asking for peer reviews. The previous courses at least provided you with a understanding of what the final product should be, in this case it's make tidy data, but with no idea on how that data should look.