What term refers to the visual representation of locations where values are known, indicated by dots on a map?

The term that refers to the visual representation of locations where values are known, indicated by dots on a map, is "dot." This method employs dots to symbolize a certain quantity of an attribute at various locations, making it easy to visualize the distribution and density of data points across a geographical area. Each dot typically represents a specific number of occurrences or a specific value, allowing for immediate comprehension of where concentrations of a particular phenomenon exist.

Other terms in the choices do have specific meanings in the context of geographic data visualization. For instance, "choropleth" refers to a type of thematic map where areas are shaded or patterned in proportion to the value of a variable, aggregating data over predefined areas. "Dasymetric" mapping involves representing data by showing areas of different values using boundaries that are determined by actual distribution rather than administrative boundaries, while "multivariate" typically refers to the representation or analysis that involves multiple variables at once, which is not specifically represented by dot symbols on a map. Each of these methods serves different purposes when mapping data, but they do not specifically denote the technique of using dots to represent individual data points, which is what makes "dot" the correct choice in this context.