Your guide to a winning display. (Tables, Charts, and Graphs.

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You've found a science project idea and you're ready to run experiments to test your hypothesis. But how do you keep track of your data? And how do you turn the collected information into something visually interesting, like charts and graphs? Don't panic. Just follow this step-by-step guide.

In "The Scoop on Sunscreen" (pp. 18 to 20) you read about how one student used a data table and a bar graph to learn which sunscreens are best at blocking sunrays. Here we test something a lot simpler: ice cream.

DATA TABLE

Use a data table to record your experiment findings.

An organized data table should list your independent variables clearly. It should also have blank spaces for you to fill in the data from your experiment. Say you want to find out if different container types (plastic, paper, and styrofoam cups) affect the time it takes ice cream to melt. The cups you use are your independent variables. And melting time is your dependent variable.

To make a data table:

1. Draw a blank data table.

2. Give your table a title that identifies your variables ("The Effect of Container Type on Ice Cream's Melting Time").

3. Label the column on the left as the independent variable (Containers). Underneath, list the different containers you used for the independent variable (Plastic cup, Paper cup, and Styrofoam cup).

4. Label the columns to the right as the dependent variable [Melting Time (in minutes)]. Draw boxes under these columns in which you can record the results of each trial for each container.

5. Include columns at the far right to record the average melting time for each container. To calculate the average, simply find the total minutes for each container. Then, divide the total by the number of trials.

BAR GRAPH

Use a bar graph to compare trends in your data.

A bar graph is a great way to show how the independent variables stack up against each other. This graph shows how different containers compare in ice cream's melting time.

To make a bar graph:

1. On graph paper, draw a set of axes (x and y).

2. Give your bar graph a title ("The Effect of Container Type on Ice Cream's Melting Time").

3. Label the horizontal (x) axis with your independent variable (Type of Container), including a label of each level (Plastic cup, Paper cup, and Styrofoam cup).

4. Label the vertical (y) axis with your dependent variable [Melting Time (in minutes)] and a scale from 0 to at least the highest number in your dependent variable results.

5. For each independent variable, draw a solid bar to the height of the corresponding value of the dependent variable. Example: The average melting time for ice cream in a plastic cup is 51 minutes. Draw a bar above the "Plastic cup" label on the x-axis to the 51-minute mark on the y-axis.

The Effect of Container Type on
Ice Cream's Melting Time

Containers Melting Time (in minutes)

                Trial 1   Trial 2   Trial 3   Average

Plastic cup       55        50        48        51
Paper cup         64        59        57        60
Styrofoam cup     75        70        68        71

[GRAPHIC OMITTED]

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LINE GRAPH

Use a line graph to pinpoint changes in your data.

Choose a line graph when you want to see how continuous changes to the independent variable affect the dependent variable. For example, instead of comparing containers, you choose to focus on the rate at which ice cream melts in a plastic cup. The independent variable is now the time, and the dependent variable is the amount of melted ice cream.

To make a line graph:

1. On graph paper, draw a set of axes (x and y).

2. Give your line graph a title ("How Fast Does Ice Cream Melt in a Plastic Cup?")

3. Label the x-axis with your independent variable [Melting Time (in minutes)] with the values of the independent variable (0, 10, 20, 30, 40, etc.).

4. Label the y-axis with your dependent variable [Melted Ice Cream (in milliliters)]. Use a scale from 0 to at least the highest number in your dependent variable results.

5. Plot a point on the graph for each piece of data. Example: After 10 minutes, 3 ml of ice cream have melted. To locate this point on your graph, draw an imaginary vertical line from the 10-minute mark on the x-axis. Then, draw an imaginary horizontal line from the 3-ml mark on the y-axis. Plot the point where the lines intersect.

6. When you've plotted the points for all your data, connect the points.

[GRAPHIC OMITTED]

PIE CHART

Use a pie chart to illustrate numbers expressed in percentages of a whole. A pie chart is simply a circle divided into wedge-shaped sections. The circle represents 100 percent. The wedges represent data that are percentages of a whole. Say you took a class poll asking students if they prefer chocolate, mint chocolate chip, strawberry, or vanilla ice cream. The number of students you surveyed represents 100 percent. And each flavor, as selected by the percentage of students, represents a different wedge of the pie chart.

To make a pie chart:

1. Draw a circle with a compass.

2. Give your pie chart a title ("Ice-Cream Flavor Students Prefer").

3. Mark the center with a point. This is where each pie "slice," or wedge, will start.

4. Measure a wedge for each level of the independent variable (Chocolate, Mint Chocolate Chip, Strawberry, Vanilla). First, convert your data from percentages to angle degrees. Example: If 10 percent of students prefer vanilla ice cream, the pie wedge for vanilla would be 10 percent of the 360[degrees] circle, or 36[degrees] (360 x. 1 = 36). Position a protractor at the center point of the circle. Mark 0[degrees] and 36[degrees] angles with points on the edge of the circle. Draw a line from these points to the center of the circle.

5. Label the wedge (include its percentage).

6. Measure your next wedge from the edge of the first. When finished, the entire circle should be filled and add up to 360 [degrees].

Ice-Cream Flavor
Students Prefer

Mint Chocolate Chip   30%
Vanilla               10%
Strawberry            10%
Chocolate             50%

Note: Table made from pie chart.