Mar
22

Many people studying for CCIE are looking for a solution to better memorize and retain the new information. The biggest enemy of good memory is the fact that speed of forgetting is directly proportional to the amount of information learned. One can actually start off this and write a simple ordinary differential equation that models the forgetting process:

dY(t)/dt = V – aY(t)

where Y(t) is the amount of information memorized at moment t and V is the speed of the new information being memorized. The component -aY(t) demonstrates the forgetting effect described above (speed of the forgetting is directly proportional to the amount of information learned). Integrating the equation we easily obtain:

Y(t) = V/a+const*exp(-at)

What it basically says, is that the amount of information that we memorize is proportional to the speed of learning! The exponentially decaying component does not play any major role as the time passes, and thus your know as much as you learn. As soon as you stop learning new information (or repeating the old info), your knowledge volume will decay with the speed of exponent. Not the best news in our already uneasy world!

This model, however is too simple to be valid. However, it demonstrates one important fact – unless you actively learn, you forget. The solution for the equation exhibits the well-know Ebbinghaus curve effect (Forgetting Curve), which has been known for over than century. Two methods can help you overcome the forgetting effect, and they are active learning and spaced repetitions. Let’s start with...

Active Reading

Active learning has many forms. The most basic involves transforming knowledge in the series of questions that could be answered in a short manner. For the demostration, look at the following blog post:

MSTP Tutorial Part I

Read every paragraph, and come up with a few questions for each.

Q: What is the major drawback of the mono spanning tree?
A: Impossible to engineer traffic flow for different VLANs

Q: What is the major drawback of PVST?
A: Does not scale with the number of VLANs

Q: What was the main idea of MISTP?
A: Decoupling STP instances from VLANs.

Q: How did the original MISTP instance convey STP information?
A: Every instance has its own BPDU sent on every link.

Q: How was the VLAN to instance mapping information distributed in MISTP?
A: Manually on every switch, no automatic protocol.

Q: What is the general rule to avoid MISTP inconsistencies?
A: If VLAN is filtered on the link, make sure the respective instance is not forwarding here.

And so on. The first time you will probably read over a body of knowledge without any questions. Take another pass, and this time write down your questions. Try doing it so that the answers are short and easy to remember. Do not mix multiple concepts in the same question. Your first pass will probably result in many questions and it should be the most intense one. However, as time passes and you return to the material for repetition, you will probably condense the amount of questions. It’s a good idea save any images and figures, as they are good anchors for your visual memory. Of course, the “asking questions” procedure could be applied to any material, for example CCIE technology-focused practice labs. You can use IOS code samples as answers to questions like: “How would you configure GDOI profile?” Do not forget to type in the code samples, don’t simply copy-paste them. This approach might look simplified and indeed, there exist other, more complicated, methods of active reading, such as SQ3R. All active reading methods require intense concentration and practice, but the result surely worth it. Now, to the next stage:

Spaced Repetitions

While active reading greatly helps in learning, you still need repetitions to keep your knowledge fresh. There has been some research done on the optimal repetition intervals, and you can find it on the Internet. Personally, I prefer using the algorithms developed for SupeMemo application. I highly recommend anyone reading the following article: Using Supermemo method without a computer. There is a table there, suggesting the optimal repetition intervals – in 4, 7, 12, 20 days and in a month. The list continues into the scales of years, but for the purpose of exam preparation you may stop at 20 days or a month. When repeating, abridge the number of questions, condense the information and retain only the key concepts. Focusing on core facts will reduce the information load but still help you remember. If you’re practicing IOS configurations, make sure you type in your configurations using the “notepad” copy & paste method during 2nd and 3rd repetitions. You may not even use the actual routers when doing 3rd and further repetitions. Starting with 4th repetition, just skim over and make sure you clearly recall the core concepts. If you find this routine too time consuming, you may leave just 3 spaced repetitions.

The link provided above would give you recommendations on proper training schedule. You may want to optimize it using some modern calendar software (or even getting the free/commercial versions of SuperMemo software). For instance, you may use Google Calendar service as your organizer (what is cool is that you may share your calendars with friends and see how all of you progress). Suppose that you are working with ours IEWB-RS VOL1 (technology focused labs). Choose the amount of material you can easily practice every day, without putting too much stress on yourself. For example, today you spent some time practicing IEWB-RS VOL1 Labs 13.1-13.5 (Section IP Services) using the active learning approach. As a result, you ended with a series of condensed questions & answers for every lab. After that, you add notes to your calendar to repeat the same labs in 4, 7 and 12 days. Therefore, you get some work scheduled already. Keep in mind that repetitions took less time than the full-blown practice. Thus you may easily combine 3rd and 4th repetition with practicing another five labs, e.g. 13.6-13.10. It is not mandatory to practice all labs from the same section. You may “interleave” QoS and IP Services focused labs, or even combine the full-scale labs from IEWB-RS VOL2 with technology focused labs from VOL1, provided that you already have good technology coverage.

A few tips on working with our VOL2 labs. There are total of 20 labs, and you may spend quite some time working through all of them, as every single lab might take about 8-16 hours. You may use the following guidelines:

a) Do not start working with VOL2 labs unless you’re confident with most technologies from VOL1. This is important, as VOL2 is not designed to be an “easy reading” :)
b) Mark the tasks that you found hard on your initial attempt. During your second repetition, work though the core section of the labs (Switching, IGP and BGP) plus the marked non-core tasks.
c) During your third repetition, skim over the lab texts and solutions, focusing on the tasks that you marked as “hard”. It might not benefit you to repeat more than three times, but if you got a lot of free time, you can do even four repetitions.

During your final stage of preparations, you will probably find yourself repeating the condensed information from VOL1/VOL2 labs. Before attempting the lab exam, you may want to take at least one or two Mock Labs to gauge your readiness. The Mock Labs are not designed to be “repeated” - you should probably schedule a new lab every time to get more unbiased result. However, if you want a testing tool that adjusts to your level of readiness plus changes every time - you may want to try out Polymorphic Assessment Lab, which automatically generates different labs on the same physical topology.

Now, the final part: if you want to retain the knowledge learned, keep repeating the information on monthly and yearly basis. This may end up in a life-long schedule, as you will keep adding new information to your calendar of repetitions. The process worth itself as the active learning methodology and optimally spaced repetitions are proven to be an extremely effective learning tool.

Petr Lapukhov, 4xCCIE/CCDE
About Petr Lapukhov, 4xCCIE/CCDE

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