Data Table
A data table organizes measurements into labeled rows and columns so patterns can be seen and the data can be graphed.
Definition
A data table is a chart of rows and columns where you write your measurements, with each column titled and given a unit so the numbers have meaning. The standard layout puts the independent variable in the first column, one column per trial for the dependent variable, and a final column for the mean, under a title that states what the table shows. As the primary record of an investigation, it holds raw values with consistent units and significant figures, keeps derived statistics in clearly separated columns, captures metadata such as date and instrument, and preserves the raw readings unaltered, since every graph and calculation is rebuilt from it.
Example
For a plant experiment, one column reads "Day" and the other "Height (cm)": Day 1, $2.0$; Day 2, $2.5$; Day 3, $3.1$; Day 4, $3.8$. A ramp table titled "Effect of Ramp Angle on Cart Roll Distance" has columns Angle (degrees), Trial 1 (cm), Trial 2 (cm), Trial 3 (cm), Mean (cm), with the $20^\circ$ row reading $78$, $80$, $79$, mean $79$. A density table lists mass (g, $\pm 0.01$), initial water level (mL), final level (mL), displaced volume (mL), and density (g/cm$^3$); for an aluminum sample, $13.50\ \text{g}$, $20.0\ \text{mL}$, $25.0\ \text{mL}$, $5.0\ \text{mL}$, $2.7\ \text{g/cm}^3$, so a reader can check both the subtraction and the division.
Key Insight
Build the table before you start the experiment, so you know exactly what to measure and never skip a trial. The table's structure mirrors the experiment's design; if you cannot decide what goes in the first column, you have not settled on your independent variable. A well-built table makes errors visible, because an outlier in a row of trials or a mean that does not match its inputs jumps out on the page long before it corrupts a graph.