Beth wanted to find out whether or not salt affects how quickly ice melts. She used an ice cube tray to make 10 ice cubes of the same shape and size. Then, she placed the ice cubes on the same windowsill. She sprinkled each ice cube with one teaspoon of salt, and timed how long it took for the cubes to melt. She recorded all of the data. If someone else read the data, would he or she be able to make an accurate conclusion about the effect of salt on ice?

Question

Beth wanted to find out whether or not salt affects how quickly ice melts. She used an ice cube tray to make 10 ice cubes of the same shape and size. Then, she placed the ice cubes on the same windowsill. She sprinkled each ice cube with one teaspoon of salt, and timed how long it took for the cubes to melt. She recorded all of the data.  If someone else read the data, would he or she be able to make an accurate conclusion about the effect of salt on ice?

anonymous · Answer

Nope.  She sprinkled the same amount of salt on every ice cube.  There's no positive or negative control in this experiment.  Neither is there any variation in the amount of salt used, hence it's impossible to study the relationship between salt and time needed for ice to melt

anonymous · Answer

Nope. there is no control