## 5 Discussion
### Experiment 2  
The effect of the number of wire roots on anchoring strength was somewhat surprising, with Test 2, utilizing a partial array, producing unexpectedly high mean anchoring strengths. Test 2, configured with a four-root partial array, produced mean anchoring strengths for sediment conditions 1-3 of 19.3 lbf, 30.9 lbf, and 3.9 lbf, respectively. Test 3, configured with the anchor spike only, produced mean anchoring strengths for conditions 1-3 of 15.3 lbf, 15.9 lbf, and 2.0 lbf, respectively. A two-factor ANOVA with replication was conducted. The first null hypothesis (that the mean anchoring strengths for each configuration are equal) is rejected with an f-value of 96.928, an f-critical value of 3.03, and a \(p\)-value of 3.30 \(\times\) 10\({}^{-32}\). The second null hypothesis (that the mean anchor failure tensions for each sediment condition are equal) is rejected again, as it was in Experiment 1, with an f-value of 611.065, an f-critical value of 3.03, and a \(p\)-value of 3.41 \(\times\) 10\({}^{-99}\). Finally, the third null hypothesis (that there are no interactions between the factors) is rejected with an f-value of 45.679, an f-critical value of 2.406, and a \(p\)-value of 4.59 \(\times\) 10\({}^{-29}\). As expected per our hypothesis, the average anchoring strength for condition 3 (beach sand) decreases from a full array, to a partial array, to none. In conditions 1 and 2, however, the partial array produced much higher anchoring strength than the full array. Two potential explanations for this unexpected result are offered. First, due to a several-day-long delay in testing between Tests 1 and 3 (the full array and no array, respectively) and Test 2 (the partial array), continued settling and firming were observed for conditions 1 and 2. For efficiency, the full-array tests were conducted first before removing four of the roots to conduct the partial array tests. Settling time, combined with decreasing ambient air temperatures, may have caused stiffening of the clay and silt samples, leading to higher anchor failure tensions. The beach sand, by contrast, being very homogeneous and stable, provided a more reliable test environment, and the resulting mean anchoring strengths behaved according to our hypothesis. Second, the wire roots, when in the partial array configuration, were prone to tangling during injection, leading frequently to a snarled deployment within the clay and silt samples. This, especially when combined with firmer sediment, may have contributed to the higher anchoring strengths. Such behavior, although more effective at holding fast, could be catastrophic in an actual deployment because it might prevent the successful retraction of the array. It is recommended that those seeking to replicate this experiment ensure sample equilibrium before collecting test data by conducting standardized pulls at regularly-spaced time intervals until a consistent anchoring strength is achieved for a particular sediment sample. To determine whether the presence of the complete array contributed significantly to anchoring strength under vertical loads, a two-sample \(t\)-test, assuming unequal variancesand with a significance level of 0.05, was conducted to compare the data from Test 1 (full array) with those of Test 3 (spike only) for each sediment condition. Three two-sample \(t\)-tests, assuming unequal variances, were conducted comparing the anchoring strength data for conditions 1-3 of Tests 1 and 3, with a significance level of 0.05. The first \(t\)-test, comparing condition 1 samples, resulted in a t-statistic of 1.784 and a two-tailed \(p\)-value of 0.08. The second \(t\)-test, comparing condition 2 samples, resulted in a t-statistic of 0.219 and a two-tailed \(p\)-value of 0.828. The third \(t\)-test, comparing condition 1 samples, resulted in a t-statistic of 11.563 and a two-tailed \(p\)-value of 1.662 \(\times\) 10\({}^{-13}\).