Essay about PREDICT 401 Assignment 1 V1 2015 02 08

Words: 3232
Pages: 13

Assignment #1
Daniel Case

Abalone populations are an economic and recreational resource that is threatened by a variety of factors, which include pollution, disease, loss of habitat, predation, commercial harvesting, sport fishing, and illegal harvesting. As a result of the aforementioned factors, abalone populations have declined considerably, pushing some abalone species to the verge of extinction. To help curb over harvesting and better protect abalone populations, it is important for biologists to efficiently and quickly determine the age composition of a regional abalone population.

The purpose of this report is to examine the data from an observational study of abalone in Tanzania. The intent of the
…show more content…
Rather, the variables appear to be skewed to the right, which is confirmed by the normal probability plot below each variable’s histogram.

Chart 2.1 Chart 2.2 Chart 2.3

Abalone Rings (i.e. Age):
One of the key variables within the dataset is the number of abalone rings, as this is a traditional predictor of age. To better understand the correlation between abalone rings and its physical characteristics, three charts were created to plot rings against volume, density, and weight (each of which were segmented by sex). In all three plots, there is a considerable degree of spread and variation between abalone rings and physical measurements, which indicates that volume, density, and weight are unlikely to predict abalone age.

However, there is an interesting development within the plots that causes some degree of concern regarding the accuracy of the abalone sample. Ring counts are supposedly the best measure of age used by biologists today; therefore, one would expect a strong correlation between low ring counts and infant abalone. While the plots do show some degree of clustering among infant abalone and low ring counts, there is still considerable variation (i.e. enough to cause concern). Assuming that ring counts are indeed the best methodology for determining age, then the figures within the charts indicate that the study’s data may have been influenced by some external