Students’ perceptions of teaching quality are vital for quality assurance purposes. An increasingly used, department-independent instrument is the (Cleveland) clinical teaching effectiveness instrument (CTEI). Although the CTEI was developed carefully and its validity and reliability confirmed, we noted an opportunity for improvement given an intermingling in its rating scales: the labels of the answering scales refer to both frequency and quality of teaching behaviours. Our aim was to investigate whether frequency and quality scores on the CTEI items differed. A sample of 112 residents anonymously completed the CTEI with separate 5-point rating scales for frequency and quality. Differences between frequency and quality scores were analyzed using paired t tests. Quality was, on average, rated higher than frequency, with significant differences for ten out of 15 items. The mean scores differed significantly in favour of quality. As the effect size was large, the difference in mean scores was substantial. Since quality was generally rated higher than frequency, the authors recommend distinguishing frequency from quality. This distinction helps to obtain unambiguous outcomes, which may be conducive to providing concrete and accurate feedback, improving faculty development and making fair decisions concerning promotion, tenure or salary.