Data and Analyses

Regression tests were run to determine whether there would be any significant correlation between either the average size of the barnacles and the slope, temperature, number of live barnacles, direction, or rock texture, or between the area covered by barnacles and the variables mentioned previously.

Table 1: Summery of the results from the regression tests. The average barancle size and density were tested against the variables listed under 'Independent Variables' , p-values<0.05 are significant.
	Average Barncle Size			Area Covered by Barnacles
Independent Variables	df	F	p-value	df	F	p-value
Slope	44	4.98	0.031	44	1.42	0.240
Temperature	44	2.83	0.100	44	2.07	0.158
Number of Live barnacles	44	0.07	0.793	44	42.21	6.91E-08
Exposure	44	12.48	0.001	44	3.83	0.057
Full Compass Direction	44	0.99	0.326	44	0.11	0.737
Half Compass Direction	44	2.50	0.121	44	1.55	0.220
Surface Texture	44	0.57	0.452	44	2.14	0.151

The only significant correlations that were found were between; slope and size, exposure and size, and number of live barnacles and area covered. The result of the regression test between exposure and area covered was very close to being significant with a p-value of 0.057, which would help reassert that the exposure is correlated with the barnacles. The variables that showed significant correlations were graphed, in The Graphs Page, to better visualize the relationship. The graph showing the correlation between the number of live barnacles and the area covered is not included becuase in the equation used to find the area covered by the barancles, the number of live barnacles is included as a variable, thus the two are correlated and the significant p-value is of no surprise.

The Equation used to find the area covered by the barnacles was the following:

The variables that showed no significant correlation, temperature, direction, and texture, were due to lack of proper data. The temperature of the rock depended on the sun exposure and weather patterns at time of measurement and thus fluctuated. In order to run a proper test, the temperatures would have to be recorded year around in order to get complete data. In this way research can also be one on how much the temperature fluctuates, on average, between the low and high tide lines. Also, texture was a variable which would fluctuate frequently, mainly due to the fact that the quantitative measurement was derived from a qualitative observation which was biased by the researcher. A better system would have to be set up to quantify texture in the field in order to produce less skewed data. Finally, the direction the area was facing was not precisely measured because the compass became unavailable for most of the data collection period. The direction could only be estimated, making the data more inaccurate, and thus producing non-significant results. However, it is interesting to note that the half compass direction was more significant to the full compass direction, in both regression tests, suggesting that the degrees the area is facing away from north could be correlated to the size of the barnacles and the area they cover.