Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Scores may become more reliable after daily repetition of the dot probe task for several weeks (Enock et al. 2014); this repetition is of course not feasible for most ABT studies, which typically take place in a single session and seek to measure pre-treatment bias.
Category: