An audience response system (Poll Everywhere) was used in a first-year undergraduate module with 500 students. The students were taught in lectures how to use the spreadsheet Excel and provided with spreadsheet exercises to be completed outside lectures. The audience response system was used to create multiple choice questions on Excel some of which were on the outside lectures exercises and were answered by students unsupervised, while others were answered in lectures in a supervised exam type structure. Strong evidence of studentsí collusion - in terms of sharing the answers to the unsupervised questions was found. In a significant number of cases this amounted to students obtaining the answers to the multiple choice questions without obtaining any understanding of the subject matter Ė spreadsheets. Confirmatory evidence of this is obtained by comparing studentsí scores on the supervised vís unsupervised multiple choice questions.