Coping means to invest one's own conscious effort, to solve personal and interpersonal problems, in order to try to master, minimize or tolerate stress and conflict. Coping means to invest one's own conscious effort, to solve personal and interpersonal problems, in order to try to master, minimize or tolerate stress and conflict. The psychological coping mechanisms are commonly termed coping strategies or coping skills. The term coping generally refers to adaptive (constructive) coping strategies. That is strategies which reduce stress. In contrast, other coping strategies may be coined as maladaptive, if they increase stress. Maladaptive coping is therefore also described, when looking at the outcome, as non-coping. Furthermore, the term coping generally refers to reactive coping, i.e. the coping response which follows the stressor. This differs from proactive coping, in which a coping response aims to neutralize a future stressor. Subconscious or non-conscious strategies (e.g. defense mechanisms) are generally excluded from the area of coping. The effectiveness of the coping effort depends on the type of stress, the individual, and the circumstances. Coping responses are partly controlled by personality (habitual traits), but also partly by the social environment, particularly the nature of the stressful environment. Hundreds of coping strategies have been identified. Classification of these strategies into a broader architecture has not been agreed upon. Researchers try to group coping responses rationally, empirically by factor analysis, or through a blend of both techniques.:751 In the early days, Folkman and Lazarus split the coping strategies into four groups, namely problem-focused, emotion-focused, support-seeking, and meaning-making coping.:303 Other research, like Weiten, for instance, identifies four types of coping strategies:, like Appraisal-focused (adaptive cognitive), Problem-focused (adaptive behavioral), Emotion-focused, Occupation-focused coping. Billings and Moos added avoidance coping as one of the emotion-focused coping. Some scholar questioned the psychometric validity of forced categorisation as those strategies are not independent to each other.:753 Besides, in reality, people can adopt multiple coping strategies simultaneously. Appraisal-focused strategies occur when the person modifies the way they think, for example: employing denial, or distancing oneself from the problem. People may alter the way they think about a problem by altering their goals and values, such as by seeing the humor in a situation: 'some have suggested that humor may play a greater role as a stress moderator among women than men'. People using problem-focused strategies try to deal with the cause of their problem. They do this by finding out information on the problem and learning new skills to manage the problem. Problem-focused coping is aimed at changing or eliminating the source of the stress. The three problem-focused coping strategies identified by Folkman and Lazarus are: taking control, information seeking, and evaluating the pros and cons. However, problem-focused coping may not necessarily adaptive, but backfire, especially in the uncontrollable case that one cannot make the problem away.:303