This experiment was set up to test the reaction times of older people against their younger counterparts. The set up was simple, having each participant answer five mathematical subtraction problems while being timed. The problems were presented on individual flash cards. Each time for the five questions was then logged. There were sixty participants overall and they were divided into two categories based on age. Those categories were over twenty-five and under twenty-five years old. For this experiment, the independent variable was age and the dependent variable was the time it took them to complete the problems. The control was the group that was under twenty-five as the experiment was on the effects of aging on reaction time. This means the under twenty-five group was tested just to provide a basis for comparison.
The top table is those who are under twenty five, while the bottom is the experimental group, those that were over twenty five. The mean is higher in the over twenty five group, but there must be some work done to test for the significance of that difference. The probability of an 8.52 score for the first group can be calculated through its z score of 2.24. The p value for that z score is .0125, meaning the chance of a member of the control group reaching the mean of the experimental group is 1.25%. However, the odds of a member of the experimental group reaching the control group mean are much better, as the standard error amongst the older group is much larger. Running the same calculation gives a value of 20.32% for that feat.
While this experiment seems to show that older people have delayed reaction speeds, it may just be the case that one outlier is affecting the numbers significantly. A member of the experimental group took over thirty-five seconds to complete the exercise, and without this score that group’s mean falls to 7.58, actually lower than the mean for the entire control group. If the outliers were removed for both groups, the result would be a negligible difference between the means. For this reason, the experiment is inconclusive and will need more studying to figure out. A large sample size and more divisions between ages would be good ways to improve it in the future. In fact, an experiment in which specific age and reaction speed were both recorded would allow for more detailed analysis and regression to be undertaken, improving the knowledge that could be gained from the experiment.