Probability: Group Experience

April 01 2015
By: Terry L. Mathis

A worker using the wrong tool for a job injures his hand. Another worker has used the same wrong tool numerous times with no injury. One worker retires having used this tool his whole career with no injury and another retiree has had three injuries related to using that tool. Each experience is different, and thus, each perception of the risk is different. Some think the practice is dangerous and some think it is not. Who is right and who is wrong?

We express a range of experience mathematically by calculating probability. With enough data points we can establish a pattern to this risk that may not be obvious to anyone who is a data point, but is accurately describing the experience of the large group. Sharing the findings of a probability study can actually change and norm the perceptions formed by differing experiences within the group. This new perception can more accurately describe the risk and encourage taking precautions against the risk even among those whose experience hasn't detected the possibility of accidental injury. Perceptions, if not thus managed, will vary by experience. Managing the accuracy of perceptions is a powerful tool for improving safety performance that many organizations have not utilized.






Terry L. Mathis

Terry Mathis, Founder and CEO of ProAct Safety, has served as a consultant and advisor for top organizations the world over. A respected strategist and thought leader, Terry has authored five books, numerous articles, videos and blogs, and is known for his dynamic and engaging presentations. EHS Today has named him one of the '50 People Who Most Influenced EHS' four consecutive times. Business leaders and safety professionals seek Terry's practical insight and unique ability to introduce new perspectives that lead to real change.