The initial approach to measuring individual differences in sensation was the use of absolute thresholds. In the 21st century, researchers use a more sophisticated approach that takes an observer's response bias into account. This approach is termed theory.

Signal Detection Theory

Explanation:

According to this theory, there are a number of factors that determine how a system will detect a signal and the point at which the threshold level will be pinpointed. E.g. in humans factors such as fatigue, experience, expectations can affect the applied threshold.

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.

1. artillery

2. jose san martin

3.their economies remained dependent on outside powers.

4. drafted new economies

5. democracies have replaced dictatorships