Most current models of speech production predict interference from related context words in picture-naming tasks. However, Glaser and Dungelhoff (1984) reported semantic facilitation when the task was changed from basic-level naming to category-level naming. The authors explore two proposals to account for this change in polarity of the semantic context effect: the semantic selection account by Costa, Mahon, Savova, and Caramazza (2003) and a response-congruency account. Experiments 1a and 1b show that category names induce semantic interference in basic-level naming, a finding that disproves the semantic selection account and is in line with the response-congruency account. Experiment 2 reveals that response congruency is probably a major contributor to the overall facilitation effect in categorisation tasks. Finally, Experiment 3 tests and confirms a prediction of the response-congruency account in basic-level naming with subordinate-level distractors. The authors conclude that the available evidence support the response-congruency account and suggest that this congruency effect is localised at the stage of constructing a preverbal message. The following are appended: (1) Stimulus materials used in Experiment 1a; (2) Stimulus materials used in Experiment 1b; (3) Stimulus materials used in Experiment 2; and (4) Stimulus materials used in Experiment 3. (Contains 3 tables and 3 footnotes.)