Diego conducted an experiment to find out what kind of ball bounces the highest when dropped from a five-foot platform. He used a golf ball, a tennis ball, and a soccer ball. He dropped each ball from the balcony once. Diego recorded his observations after each drop. What can Diego do to best improve the reliability of his results?

Drop each ball from the platform three more times . Reliability or precision means how much the measured values vary from each other when measured by performing the same experiment repeatedly.  When measuring values by observation in physical experiments of this nature, it is best to perform the experiment and measure the values at least three times. The more the better.  In such measurements there is always a margin of error, e.g., how at exact time you start and stop the stopwatch. There may also be a bit harder or softer side of ball (tennis ball strip) touching the ground. In order to minimize such and some other margin of errors, it is advisable to measure the values more than 3-4 times, and then take their mean. The value now obtained would be would reliable or precise.  Second and third options are incorrect because they will have no effect on improving the reliability.  In order for the fourth option to be correct, the other people need to do the same (not similar) experiment, with the same balls and same conditions/instruments. That would be equivalent to repeating the experiment 3-4 times, which is already covered by first option.

Explanation: