Graph and Interpret Results

A graph turns a table of numbers into a picture you can read at a glance. A good scientist does not just plot the points — they label every part of the graph so any reader can understand it, and they describe the trend in plain words. In this lesson you will name the parts of a graph, plot points from a table, read values back off a graph, and explain the pattern you see.

The Parts of a Line Graph

• Title — what the graph is about, written above the chart (e.g. "Plant Height vs Day").
• X-axis — the horizontal axis, usually the variable you change (the independent variable, like time or day).
• Y-axis — the vertical axis, usually the variable you measure (the dependent variable, like height in cm).
• Units — written next to each axis label so the reader knows what 5 means: 5 cm (about 2 in), 5 sec, 5 g (about 0.18 oz).
• Scale — equal spacing between values (every gridline = the same step, like 0, 2, 4, 6...).
• Data points — one dot for every measurement, placed where the x-value and y-value meet.
• Trend line — a single line drawn through the points to show the overall pattern.

Plotting Points From a Table

Each row of your results table becomes one point on the graph. Read the x-value first, slide along the x-axis until you reach it, then go up until you reach the y-value. Place a small clear dot. Do this for every row, then connect the dots in order to see the shape of the relationship.

Reading Values Off a Graph

1. Find the x-value you want on the x-axis (for example, Day 4).
2. Go straight up from that x-value until you hit the line or data point.
3. From there, go straight across to the y-axis and read the y-value.
4. Write the answer with its unit (for example, "12 cm at Day 4").

Describing the Trend

After you plot, step back and describe the overall shape in one sentence. A rising line means the y-value increases as the x-value increases (positive trend). A falling line means y decreases as x increases (negative trend). A flat line means y stays about the same — no clear relationship. Steepness matters too: a steep rising line means y grows fast, a gentle rising line means y grows slowly.