This made-up classroom experiment investigated whether varying the duration of daily light exposure would alter the growth of seedlings. Two groups of twelve bean seedlings each were set up. One group was exposed to light for eight hours each day. The other group was exposed to light for twelve hours each day. Each group was watered with 40 milliliters of water every other day. Both groups were observed over a period of fourteen days. The experiment was set up to examine the interpretation of small data sets and not to discover a general rule for growing beans.

At the end of the observation period, the average height of the seedlings in the eight hour group was 11.2 centimeters and the average height of the seedlings in the twelve hour group was 13.6 centimeters. The difference in mean height was 2.4 centimeters. Two seedlings in the eight hour group developed yellow leaves and one seedling in the twelve hour group developed yellow leaves. No seedlings died during the experiment. These observations are consistent with the relationship between light exposure and seedling growth. These observations, however, do not prove that light exposure for a longer period of time caused the seedlings to grow taller.

There are several limitations to this study. Seedlings were placed into groups based on their position on a tray, rather than be determined randomly. Initial height of each seedling was not recorded, therefore the groups may have been different prior to treatment. Finally, intensity of the light was not measured and although both groups were in the same room, their distance from the lamp was not the same. Any of the above factors could account for a difference in final group means. The available data does not allow an estimate of the extent to which each of these factors may have influenced results.

A future study should record the initial heights of the seedlings, randomly assign the seedlings, measure light intensity for each pot, and use more than one tray for each light condition. Repeating the study would help to determine if the results reflect a real phenomenon. These results provide some support for the hypothesis relating to exposure to light, but do not indicate the presence of an optimal lighting schedule. Reporting the results of the study is warranted, as the limitations have helped to interpret the results.