User: | Open Learning Faculty Member:
I did not encounter any major issues with the implementation of my design and also did not make any changes to my design while I was in the process of collecting data. However, if I were to repeat this experiment, I would change some aspects of my design.
When performing the statistical analysis for each set of data related to each alternative hypothesis, the results show no statistically significant difference for both cases. Therefore, my null hypothesis for my first analysis cannot be rejected and my hypothesis has to be rejected. For the second analysis, my null hypothesis can be rejected and my hypothesis can be accepted.
First analysis:
H0 = The number of birds of the genus Larus spp. present in the intertidal zone does not vary in function of the tide level.
H1 = The number of birds of the genus Larus spp. present in the intertidal zone varies in function of the tide level.
Second analysis:
H0: The number of birds of other genus present in the intertidal zone varies in function of the tide level.
H1: The number of birds of other genus present in the intertidal zone does not vary in function of the tide level.
Based on my field observations, I predicted that there would be a significantly higher number of gulls present in the intertidal zone at low tide than at high tide. I believe that I wasn’t able to reject my null hypothesis because my sample size was too small (F=3.6078 ˂ Fcrit 4.4139 ; p = 0.074 ˃ 0.05). My p-value was close to being lower than 0.05. Hence, if I were to repeat this experiment, I would collect data on at least 30 occasions at low tide and 30 occasions at high tide. Furthermore, there seem to be significantly less gulls in the intertidal zone at low tide in the morning than in the afternoon. I would therefore divide my data collection further into low tides occurring in the morning and low tides occurring in the afternoon. This would allow me to determine if the time of the day also influences the presence of gulls in the intertidal zone at low tide.
Designing this experiment has allowed me to appreciate how much effort is put into this process. I now better understand the complexity of experimental design. I am also aware that every detail needs to be carefully thought and that small mistakes make a significant difference in the outcome.