  Measurements carried out or reinterpreted within the framework of effective
field theory (EFT) will constitute a key component of the LHC legacy in the
quest towards physics beyond the standard model. Numerous EFT measurements were
already published by the CMS Collaboration. In the top quark sector, four
distinct approaches to EFT have been identified, each successfully applied in
several analyses. We review the pros and cons of each approach, while
illustrating them with recent analyses in which they were adopted.
