Explain any vocabulary students will need to understand graphing and scatterplots. For example, the term "correlation" describes a relationship between two sets of data and "line of best fit" is a line drawn through the scatterplot graph that estimates the relationship between the two sets of data. Younger students may benefit from a word list. Older students may have a crossword puzzle to complete or definitions that they must match with each vocabulary word simply by carefully reading the definition.
Demonstrate a scatterplot and how it works. You may need an overhead projector or whiteboard for a whole class demonstration. Show students the two sets of data and how to plot them on the graph, then explain how a line of best fit helps to interpret the data as it appears on the graph. Consider asking students to come up and draw dots where they think a data point should be placed. The groups of data could represent anything from the ages of students in the classroom to arm versus leg length. The important thing is to demonstrate how to plot two sets of data on X and Y axes.
Allow students practice time with their own rulers and graph paper. They should use the same type of data from the demonstration with slightly different pieces of data so that their results are similar for performance verification. Instruct students to draw dots representing all sets of data, then draw a line of best fit through the area on the graph with the most dots in the same place. Each student should work on their own to have practice with plotting data, but it is often a good idea for pairs of students to discuss their findings together to verify methods of identifying and plotting data.
Conduct an evaluation so that students can demonstrate their understanding of scatter plot graphing. A formal evaluation (such as a quiz) can give students the opportunity to read an actual graph and then answer questions that determine their level of understanding. A more informal way to assess knowledge would be to ask general questions of the class, such as, What is the trend shown on the scatterplot? and What assumptions can you make about the sets of data by looking at the scatterplot?