The PowerPoint-assisted lecture (slide-lecture) is a common lecturing approach in higher education, in spite of much criticism of its use. Its popularity is facilitated by its affordances for multimodal instructional design, e.g. text with images and speech. Little is known about the integration of different semiotic modalities within the instructional communication practices of slide-lectures nor the learning conditions that they create. Given that text bulletpoints are ubiquitous in slide-lectures, and may impose linearity into instructional communications, this study explores the extent to which lecturing speech is systematically coordinated with slide-text. Eleven slide-lectures given in psychology departments across the UK were recorded and transcribed. Patterns of semantic matches between speech and slide-text were analysed to produce similarity scores for each lecturer. Lectures were scored using an integration scoring system of 0-1, with 1 indicating a perfect match of speech and slide-text. There was significant departure from a systematic voicing of the slide text (i.e. reading off the slides). Two characteristic speech-slide relationship styles were identified. The 'referent' style is one in which the slide is an object of reference for the lecturer to comment on and the 'scaffolding' style is one in which the slide-text is blended into the spoken narrative. Consequences of the lecturer's coordination with presentational slides are discussed in terms of the learning environment it might produce. It is suggested that whichever relationship a lecturer has with their slide-text, students might benefit from the integration being consistent.