As part of the balancing test, you need to consider whether data subjects would expect their data to be used in the way in which you are using it, taking into account your particular circumstances. Specifically, you should consider if: your intended purpose and method of processing are widely understood by the data subjects (eg you informed them about how and why you are processing data by providing them with a privacy notice) how long ago the data was collected and if there have been any changes in technology or context which may affect reasonable expectations (eg any changes in technology that affect the services you provide) you are doing something new or innovative with the data (eg processing data in a new or innovative way that individuals may not expect, such as market research involving emotional response analysis and brain activity) actual evidence about expectations exists (eg from market research or pre-existing studies) For more information, read Legitimate interest assessments.