A curve that summarizes the change in some outcome over time is called a growth curve.

• A. Growth curve
• B. Regression line
• C. Histogram
• D. Scatter plot

Answer: (A)

Growth curve describes how an outcome changes over time, capturing the trajectory across repeated measurements. It’s used in longitudinal data to summarize development, such as cognitive scores across ages or height over years, and it shows the overall pattern of change, including potential nonlinearity and individual variation around the average path. The other options don’t fit this purpose: a regression line describes the relationship between two variables and isn’t inherently about time-based change; a histogram shows the distribution of a single variable and is not a time trajectory; a scatter plot displays data points for two variables and, on its own, doesn’t summarize change over time as a trajectory.