Happiness is typically measured using subjective measures – e.g. self-reported surveys – and/or objective measures. One concern has always been the accuracy and reliability of people's responses to happiness surveys. Objective measures such as lifespan, income, and education are often used as well as or instead of subjectively reported happiness, though this assumes that they generally produce happiness, which while plausible may not necessarily be the case. The terms quality of life or well-being are often used to encompass these more objective measures.