Holy Abalone-y!

Completed for a challenge on DataCamp, in which competitors were given data related to a Japanese abalone farm, and asked three questions: How does weight vary across male, female, and infant abalone? Can you predict an abalone's age using physical characteristics? Which characteristics are the best predictors of an abalone's age?

Using ggplot to identify statistic distributions of weight per sex, as well as the trend between age and weight, I identified potential survivor bias early on; essentially, once abalone reached a certain size or weight, they were harvested, regardless of age, leading to a decline in average or expected weight after a certain age.

To build the model, I identified whole weight, length, height, and diameter as the only four physical characteristics that were easily measurable and would not result in the death of the abalone (such as shell weight, viscera weight, etc...). These numbers were run through a model, with length, height, and diameter all being statistically significant at p <= .05, whereas weight had a p-value of 0.77 (likely due, again, to survival bias).

Finally, it was time to conclude which characteristics were the best predictors. The characteristic with the worst relation to age was shucked weight, with a correlation of 0.421, whereas the best was rings, which was perfectly linear. The problem, however, is that age is determined by the number of rings, plus 1.5; therefore, rings and age are in essence the same thing. Therefore, the shell weight was the characteristic with the strongest relationship to age, at 0.628; this suggests that the shell becomes more dense with age, regardless of abalone size.

Overall, the physical characteristics of height, length, and diameter were the best physical predictors of age which would not require extensive examination or the early harvest of an abalone. By using this predictive model, farmers are better able to estimate the age of an abalone and harvest it when the time is right, rather than waiting too long or harvesting it before it should be harvested.