I agree with you, but that is mostly because I already have a 4 year degree in Engineering and I'm assuming you do too. There is a problem in the fact that many people cannot afford that degree because their parents can't afford it (or the loans that they'd need).
Cheating degrades the quality of education at any level. Cheaters are trying to get accreditation when they shouldn't. While Cheating is all over in education (we had a couple of cases at my school), it is obviously going to be more prominent in a place like Coursera, where cheating is easier and looking for cheaters is harder.
One thing they could do is create an algorithm that checks answers much like what they do for journals, but again that's an extra load they "shouldn't" have on their employees.
I would argue it hurts after the cheating, though possibly not precisely when it occurs. Later courses, things that build on what was cheated, that kind of thing. Time (and money, and happiness) must be spent to deal with people who aren't prepared, degrading the quality of what the legitimate ones receive, and the educator's time.
There is a big crediblity difference between taking random classes and completing a program in a university.
The university has the onus to hire credible teachers, and to maintain a high reputation. You're paying for the standards they apply. Some universities aren't worth their weight and some are. The information that they have is out there. This has not changed. Textbooks have been arround for a while. Additionally professional teachers have the ability to communicate the material affectively.
Online classes can't guarantee a level of understanding of the material. Additionally online classes will never be able to guarantee that the person who signed up for the class is the actual one that gets the credit.
The algorithm for checking answers in journals is to send it to a panel of other people in the field, ask them if it checks out (obvious errors, overlooked things, etc.), and publish if it does. This model has already broken down when people outright fabricate results, it has missed blatant plagarism, and overall is largely dependent on all the parties being honest.
It wouldn't work at Coursera's scale and for a price point they can afford.
Coursera has a huge amount of data and could create their own algorithms that check for similar code in the database. It wouldn't be perfect but it could do simple string comparison against other work.
People shouldn't let cheating degrade the quality of education. You either possess the skills or you don't, and if you don't you shouldn't act like you do. It'll probably be obvious. Here's the scenario in my mind...
A: "Oh hey I know how to program Scala"
B: "Ok program Scala..."
A: "Well I only got the cert, I don't actually know."
B: "Sorry I guess you're not qualified then. Why don't you learn?"
Yeah that sounds like a great interview. How long do you let them go, half an hour, a day? Do you think you can adequately judge someones abilities like this?
I think it was more of a broad sketch of a series of interactions, not a formula for an interview. Someone represents themselves as having some skills because they are certified as having those skills; they are asked to apply those skills; etc...
Your format implies more formality than a normal conversation - I assumed you meant it in terms of an interview too, and if not that, I'm not sure what you were aiming for. I don't see conversations like that outside technical interviews.
Cheating degrades the quality of education at any level. Cheaters are trying to get accreditation when they shouldn't. While Cheating is all over in education (we had a couple of cases at my school), it is obviously going to be more prominent in a place like Coursera, where cheating is easier and looking for cheaters is harder.
One thing they could do is create an algorithm that checks answers much like what they do for journals, but again that's an extra load they "shouldn't" have on their employees.