When deciding on the type of visualization to use for a specific dataset or audience, I consider several factors. First, I look at the nature of the data itself—whether it's categorical, numerical, or time-series data. For example, bar charts are great for comparing categories, while line graphs are ideal for showing trends over time. Next, I consider the message I want to convey and the audience's level of expertise. If the audience is non-technical, I opt for simpler visuals like pie charts or bar graphs to ensure clarity. Additionally, I take into account the platform or medium where the visualization will be presented, as this can influence the design and complexity. Finally, I always aim to choose a visualization that highlights the most important insights without overwhelming the viewer.