The welfare of an individual is its state as regards its attempts to cope with its environment. Welfare varies on a continuum from very good to very poor, and it can be assessed precisely. Information about what conditions might result in good welfare can be obtained from studies of preferences, buth the importance of the preference to the individual must be assessed. Measures which show how poor welfare is when animals encounter short-term or long-term problems may be physiological, behavioural, or concerned with individual production or disease. Individuals vary in the coping methods which they use, so any one measure may indicate poor welfare and absence of evidence using one measure does not mean that there is no welfare problem.