"A person who never made a mistake never tried anything new." - Albert Einstein
Most people don't like to make mistakes, including me. It may come from parental reprimands where we were very young or from school where good grades were important and mistakes led to poor grades. In any case, we generally work hard to avoid them.
Mistakes are - as Einstein notes - often accompany trying something new. When we learn through a class or a book or whatever, we generally end up trying out the new thing we learn. To have a successful learning experience, we need a safe environment to make mistakes. When people learn to drive a car, they seldom start on the freeway; instead, they may begin in an empty parking lot or a specifically-designed area for new drivers. The safety is necessary not just for learners, but also for those around them. The necessity for a safe learning environment is a core element in adult learning theory.
One example of a safe learning environment is a virtual computer. We use these in hands-on courses at Learning Tree such as the Introduction to Cyber Security that I co-wrote. In that course, we use tools the use of which may be counter to company policies. One example is a tool that looks at resources available on other computers on a network. Other activities require using elevated ("administrator") privileges. Course participants can learn to use the tools (and "play" with them) without the fear of seriously fouling the computer's configuration or causing unexpected events on other network devices. Indeed, the virtual computers can be completely reloaded if the participant makes a serious error. The virtual computers on the virtual network provide a safe environment.
In another course I teach -- Introduction to Networking -- we discuss ways to design and configure computer networks. Our focus is on practical issues in design. By discussing these issues in a safe classroom environment, participants gain the confidence to address them in real-world situations.
Other courses provide for group discussions and activities, again in a safe environment.
What makes a classroom environment safe?
There are two essential safety issues in the examples above. One is the safety to use real-life tools in an environment where misuse won't cause real damage. We use virtual computers. Some companies may have duplicates of live systems to create a similar safe environment. Others may choose to simulate a complex system to avoid any issues with a "live" system.
In the second case, participants are in an essentially homogeneous class: virtually all participants have similar backgrounds. They usually in advance not to judge others for their mistakes and not to share the details of classroom experiences outside the group. This allows them to fully explore what they are learning and to apply it in simulated environments.
Failure can be uncomfortable, but it is an inevitable part of learning. The keys to making the most of failure in learning are a) to be willing to try things out and allow yourself to make mistakes b) to create a safe environment for failure, and c) to evaluate what caused the failure and what needs to be done to turn that into success. It's difficult to be willing to make mistakes. It's easier with a safe environment. It is also easier if we look at them as steps forward and learning opportunities instead of as steps backward that reflect negatively on our abilities.