Scatter Plot Maker

Suppose a class records study time and quiz scores for 28 students. Re-entering 56 numbers into a chart tool creates 56 chances to mistype one. Copy the two spreadsheet columns instead, paste them into this tool, and the X and Y headers tell it where every number belongs. Add a Label column when you need to identify points and a Series column when two classes or conditions belong on the same axes.

1. Put the explanatory value on X. Time, dose, distance, or temperature usually belongs on the horizontal axis. Put the measured response on Y.
2. Include units in both axis labels. Study time (hours) and Quiz score (%) answer questions that bare labels cannot.
3. Check the valid-point count. Blank rows are ignored. A row with words in X or Y stays visible in red so you can correct it rather than losing it without warning.
4. Set manual limits only when comparison needs them. Two class charts are easier to compare when both use the same axes. For a single chart, automatic scaling usually shows the pattern more clearly.
5. Choose the output for the job. SVG is best for a worksheet that may be resized, PNG is convenient for a learning platform, and Print makes a clean one-page handout.

Long point labels wrap to two lines, and the legend uses a shape as well as a colour for every series. If labels begin to cover the data, hide them on the chart and use the editable table as the key.

A chart that works on a projector can fail on a photocopy. Colour disappears, thin marks fade, and a crowded legend shrinks the plotting area. This tool assigns a marker shape as well as a colour to every series, gives best-fit lines different dash patterns, and converts the print version to black marks on white paper.

• Start with the colourblind-safe palette. It separates common colour-confusion pairs, while shapes carry the same information without colour.
• Hide value labels for dense datasets. Labels are useful for a few named observations. With 40 points they often cover the pattern the class is meant to see.
• Keep gridlines light. Gridlines help students estimate coordinates, but they should sit behind the data rather than compete with it.
• Use bubble size for one meaningful third variable. Attendance, population, or sample size can work. Explain the Size column in a caption so large markers are not mistaken for more important points.
• Prefer SVG for worksheets. Vector text and geometry remain sharp after resizing. PNG uses twice the chart resolution for software that needs a bitmap.

Print is sized for one landscape Letter or A4 page with a 10 mm margin. It removes page decoration and coloured fills, which keeps the result clear and ink-efficient.