This article written by Hélène Russell aims to look at the measurement of Knowledge projects and activities in a simple, practical way, with the aim of helping busy law firm librarians understand whether their various Knowledge Management (KM) projects and activities are having a positive effect and are value for money in a general sense. Be forewarned: the benefits of KM are often intangible and the way that KM affects tangibles can be complex, so measurement is difficult. However, that does not mean that you cannot approximate an answer which is useful for informing business decisions.