Science Fair Project Observations and Data: DATA TABLES AND GRAPHS

Remember to: Perform multiple runs of your experiment to see if you get consistent results Make sure the results you are looking for are MEASUREABLE. Follow your experimental procedure exactly. If you need to make changes in the procedure (which often happens), write down the changes exactly as you made them. Be consistent, careful, and accurate when you take your measurements. Numerical measurements are best. Take pictures of your experiment for use on your display board if you can.

Example 1 - Solubility Joey is doing an experiment on solubility. He wants to make some super-sweet Kool-Aide and wants to find the maximum amount of sugar he can dissolve in water. From his background research he has found that that solubility of a substance can depend on the temperature of the solvent (water).

Set up a data table His procedure is to take different amounts of sugar and put them in test tubes with 5 ml of hot water. He is going to watch them cool and not the temperature when he first sees sugar crystals appear. If he starts with 2.0 g of sugar and increases each test run by 2.0 grams, how would you set up his data table?

The Solubility Curve of Sugar in Water

Example 2 - Batteries Miesha has been wondering if it has been true that alkaline batteries last longer than regular “heavy duty” batteries. Her background research into batteries tells me that the chemicals involved are very different in the two batteries, and that battery life is affected by the “drain” on the battery. That is how much electricity a device demands from a battery /second. Some batteries are better where short busts of power are needed, like a flashlight; others are better at lower, constant usage, like a radio. How should Miesha set up her experiment and her data table?

Voltage Drop in Batteries Over Time

Example 3 - Detergent Althea is wondering if Oxy-Clean really is the best at getting stains out of clothing. Other detergents make the same claim. In her experiment she wants to use 4 different types of stains and put them on white T- shirts. She wants to test Oxy-Clean against, Purex, All, Tide and a cheap generic brand (Stop and Shop?) Before you set up the data table for this experiment, decide how she should measure her results?

Alternate ways of measuring Measure in terms of percent clean. (100% means the stain is completely gone) Make up a scale; 0 -5, 1-10, etc. that you can use to assign values that you can graph Print out a color scale that shows degrees of color or gray

Calculations and Summarizing Data Often, you will need to perform calculations on your data A spreadsheet program such as Microsoft Excel may be a good way to perform such calculations, and display the results. - don't forget to include the units of measurement (grams, centimeters, liters, etc.) Think about the best way to summarize your data. Do you want to calculate the average for each group of trials, or summarize the results in some other way such as ratios, percentages, etc.

Graphing Your Data: Bar graph A bar graph might be appropriate for comparing different trials or different experimental groups. It also may be a good choice if your independent variable is not numerical. (In Microsoft Excel, generate bar graphs by choosing chart types "Column" or "Bar.")

Graphing Your Data: Time Series Plot An Time Series plot can be used if your dependent variable is numerical and your independent variable is time. (In Microsoft Excel, the "line graph" chart type generates a time series. By default, Excel simply puts a count on the x-axis. To generate a time series plot with your choice of x-axis units, make a separate data column that contains those units next to your dependent variable. Then choose the "XY (scatter)" chart type, with a sub-type that draws a line.)

Graphing Your Data: Line Graph An xy-line graph shows the relationship between your dependent and independent variables when both are numerical and the dependent variable is a function of the independent variable. (In Microsoft Excel, choose the "XY (scatter)" chart type, and then choose a sub-type that does draw a line.)

Graphing Your Data: Scatter Plot A scatter plot might be the proper graph if you're trying to show how two variables may be related to one another. (In Microsoft Excel, choose the "XY (scatter)" chart type, and then choose a sub-type that does not draw a line.)

An xy-line graph shows the relationship between your dependent and independent variables when both are numerical and the dependent variable is a function of the independent variable. (In Microsoft Excel, choose the "XY (scatter)" chart type, and then choose a sub-type that does draw a line.)