An Investigation of the Therac-25 Accidents

Question 1

Describe, in your own words, what caused the accidents with Therac-25?

Question 2

Identify and describe 5 communication failures discussed in the article. For each failure, discuss what led to that failure happening and what could have been done to prevent it.

Some of these communication failures are obvious, but some are more subtle. Communications failures include any instance where somebody tried to transmit information to somebody else but couldn't, regardless of the specifics.

It helps to remember that communication failures are often mediated through systems (i.e. we build things to communicate for us and these can fail to give our message when they should). For example, if I was trapped on a desert island and put a message in a bottle, that's an attempt at communication. If the bottle sank 5 months later in a storm, that's a communication failure.