#$%^&*AU2012200812A120121122.pdf#####Abstract This invention concerns a method for measuring cognitive load. A computer implemented method for measuring a persons cognitive load comprises initially receiving 100 stroke data (Fig. 4, Fig. 5(a)) representative of hand-based strokes produced by a person 200 while performing a task. The hand-based strokes may be made by a persons finger or with the aid of a pointing device such as a pen or stylus. Then a processor 216 selecting 104 a subset of the stroke data Fig. 5(c) that meets one or more predetermined stability criteria. Then, determining 106 a measure indicative of the persons cognitive load based on the subset of stroke data. In this was the users cognitive load in an objective, uniform and non-intrusive manner by analysing the users writing behaviours. An analysis of all of a users writing strokes will bias the evaluation result, The invention advantageously improves the accuracy of the cognitive load measurement by applying stability criteria to select the best strokes for further analysis. By disregarding unstable strokes the computation costs for determining the users cognitive load is also improved.