Comparative evaluation of Information Retrieval Systems (IRSs) using publically available test collections has become an established practice in Information Retrieval (IR). By means of the popular Cranfield evaluation paradigm IR test collections enable researchers to compare new methods to existing approaches. An important area of IR research where this strategy has not been applied to date is Personalised Information Retrieval (PIR), which has generally relied on user-based evaluations. This paper describes a method that enables the creation of publically available extended test collections to allow repeatable laboratory-based evaluation of personalised search.