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:While in our case we were worried about the compatibility of the most simple updating rules of the regularization parameter with the preservation of optimal complexity results, in [16] the main concern was the determination of regularizing parameters that optimize the accuracy of the quadratic model.
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