Companies in the US spend over $100 billion on corporate training each year. Most of it doesn't work. Not in a subtle, marginal-returns way. In a "studies consistently show 70% of training content is forgotten within a week" way. The research on this has been clear for decades. The industry has largely ignored it.
The forgetting curve is not a surprise
Hermann Ebbinghaus documented in the 1880s that humans forget roughly half of new information within an hour if there's no reinforcement. Within a week, retention drops to about 20% without practice. This isn't a quirk of modern distraction — it's how memory works. Every training professional knows this. And yet the dominant format is still: present information for a day or two, test on recall, declare success.
The gap between what we know about learning and what most corporate training does is remarkable. It persists because training completion is easy to measure and behavior change is hard to measure. The metrics drive the format.
Why event-based training fails
A two-day offsite, a full-day seminar, a week-long certification course — these are event-based training. They work for creating shared experiences, building team cohesion, and establishing a shared language around a topic. They don't work for changing how people actually do their jobs day to day.
The skills that change behavior are built through repetition, feedback, and application in context. None of those happen in a conference room over two days. They happen over weeks, in the actual work, with specific correction when something goes wrong.
What works better
Spaced repetition — small amounts of learning distributed over time rather than concentrated in a block — dramatically improves retention. Active recall, where learners are required to retrieve information rather than just see it again, improves retention further. Project-based application, where skills are immediately used in realistic scenarios, is the strongest predictor of transfer to actual job performance.
This isn't new knowledge. The challenge is organizational: spaced, project-based training is harder to schedule, harder to mandate, and harder to claim as a box checked. But for organizations that care about whether training actually changes performance, the investment in better design is the only one that pays.