The function f(x) seems to be selective for the concept of "excavation". When the input word is "excavation", the function returns a value close to 1 (0.9989). This indicates a strong association with the concept. Additionally, the function is also selective for the concept of "artifacts" with a high association value (0.9959). Other words such as "reservoir" (0.0940), "outdoors" (0.0804), and "The New York Times" (0.0321) show a lower association value, indicating a weaker association with these concepts. Words like "ethics", "olympics", and "rink" have very low association values (0.0028, 0.0014, and 0.0180 respectively), suggesting that these words are not strongly associated with any specific concept.

It is important to note that these observations are based on the provided function inputs and outputs. To get a more comprehensive understanding of the function, it would be beneficial to test a larger and more diverse set of words.