The introspective method of think-aloud, traditionally used for investigating the translation process, poses important problems. This is particularly evident in the case of professional translators, where the translation process has been automatised and is difficult to verbalise. Consequently, it is necessary to test other methods, based on the researcher’s observation and analysis rather than on the subject’s introspection. The computer program Translog has proved useful. This paper considers new ways of investigating the process by means of Translog, but some methodological problems are also discussed, especially those related to the difference between the writing and the translation process. In a study of three Danish professional translators who were asked to translate two Danish texts into Spanish, some important hypotheses related to the use of Translog are tested. Specifically, the significance of pauses is investigated by comparing Translog data with data from three other sources (think-aloud protocols, retrospection and video recording).