I guess it all depends on the way it's taught. Introducing all 3 approaches at once would be confusing, yes. But starting with the basics of pressure groups and NDLs with the tables and then reinforcing that knowledge, along with, say Mutlilevel dives with the eRDP, etc.... I don't see how Interference Theory is applicable there.
Just my opinion.
My response was to this statement:
I can't believe anybody would argue against learning all that you can. Learn everything, tables, eRDP, computer, and they "why" behind each device. Doing so will only help. More knowledge is never bad.
Your final sentence that more knowledge is never bad is what I was talking about to begin with, and I was pointing out that more knowledge can indeed be bad.
What you may have missed earlier in the thread was that people are constantly confusing teaching decompression theory, which is, in your words, the "why" behind each device, with the teaching of the device itself. There are some people who think it is not possible to teach decompression theory without teaching tables, which is not true. In fact, trying to do both at once is where the interference theory comes in.
Let's say instead one were to teach decompression theory all by itself as a part of the class. Students learn that they are on-gassing nitrogen throughout a dive, and they learn that they have to off-gas it carefully during the dive itself. There is no need to mention devices that measure this at this time. Students can focus on the theory itself without having to learn a multi-step process at the same time.
Later on, we can teach how we measure decompression. If you are being taught the eRDPml and don't understand what a pressure group is, then it can indeed be helpful to point to the RDP. After all, the eRDPml is just a calculator version of the RDP, so they it makes sense.
On the other hand, computers have their own algorithms, and if you read the latest issue of DAN's
Alert Diver in which they talk about it, we really don't know much about how they were devised. Pressure groups are meaningless to them. There is nothing in the RDP or eRDPml itself that will help you understand how a computer measures decompression.
As it turns out, I do teach both. Since I have yet to have a student take the computer-only option, I have always taught the tables (or the eRDP). I teach decompression theory almost right away, right after question #5 on Knowledge Review 1, which deals with Boyle's Law. It makes sense to me to do it then, since they are seeing that the air they breathe at depth will have more nitrogen in it.
I teach the tables/eRDPml in Knowledge Review #4. I remind them of what we learned about decompression theory, and I show them how the tables/eRDPml measure it. I then teach them how the computer does it, although all too briefly because it is not a standard part of the curriculum and I am going above and beyond.
The key is this: my students need to understand decompression theory to understand how the computer works. They do not, however, need to know the tables to understand how a computer works. They are two different tools that work in very different ways.
