I love this from Jay Cross...

Formal training programs are not the only learning game in town. CLOs who
spend the bulk of their time improving the development and delivery of training
might be optimizing the insignificant. Consider this:

• According to Tom Gilbert and Peter Dean, training only accounts for 10.5
  percent of the total potential change in worker behavior. Clarity of objectives,
  working conditions and other factors are more important.
• According to the Institute for Research on Learning, at most, formal
  training only accounts for 20 percent of how people learn their jobs. Most
  workers learn their jobs from observing others, asking questions, trial and
  error, calling the help desk and other unscheduled, largely independent
  activities.
• According to Robert Brinkerhoff and Stephen Gill, people who do attend
  formal training never apply 80 to 90 percent of what they learn back on the job.
  They forget the bulk of what they’re exposed to in a matter of days.

So, formal training accounts for 20 percent x 20 percent x 10 percent of the
possible improvements you can make to worker performance. That’s 0.4 percent.