Self-Efficacy
Ralf Schwarzer and Aleksandra Luszczynska

Self-efficacy is a unique theoretical construct different from related ones, such as self-concept, self-esteem, locus of control, or self-concept of ability. Self-concept refers to an organized knowledge about oneself ("I see myself as a diligent person"), whereas self-esteem has its main focus on the emotional side of this knowledge ("I feel that I have a good character," or "I am proud of myself"). Locus of control refers to an attribution of responsibility for outcomes (internal agency versus external causation), and self-concept of ability pertains to a judgment of one's competence ("I am good at math") without reference to any subsequent action. Only self-efficacy ("I am certain that I can quit smoking even if my partner continues to smoke") is of a prospective and operative nature, which furnishes this construct with additional explanatory and predictive power in a variety of research applications. In sum, perceived self-efficacy can be characterized mainly as being competence-based, prospective, and action-related as opposed to similar constructs that share only part of this portrayal (Bandura, 1997 xClose
Bandura, A. (1997). Self-efficacy: The exercise of control. New York: Freeman. ).

Dispositional Optimism

Generalized outcome expectancies have been coined dispositional optimism, measured with the Life Orientation Test (LOT; (Scheier & Carver, 1985 xClose
Scheier, M. F., & Carver, C. S. (1985). Optimism, coping, and health: Assessment and implications of generalized outcome expectancies. Health Psychology, 4, 219-247. ). This construct reflects a sense of confidence about attaining a goal. It does not specify the cause of goal attainment, but the theory (Carver & Scheier, 1998 xClose
Carver, C. S., & Scheier, M. F. (1998). On the self-regulation of behavior. New York: Cambridge University Press. ) assumes that effort is a key self-regulatory component that is made responsible for the outcomes. In contrast, perceived self-efficacy requires an explicit attribution of expected goal mastery to one's competence. Although both constructs share the notion of optimism, the source for this optimism is different (Schwarzer, 1994 xClose
chwarzer, R. (1994). Optimism, vulnerability, and self-beliefs as health-related cognitions: A systematic overview. Psychology & Health, 9, 161-180. ). Dispositional optimism is the broader construct because it includes ability attribution as one possibility among others (see Dispositional Optimism in Other Constructs).

Hope

The hope construct is two-dimensional, consisting of agency and pathways (Snyder, 1994 xClose
Snyder, C. R. (1994). The psychology of hope: You can get there from here. New York: Free Press. , 2002 xClose
Snyder, C. R. (2002). Hope theory: Rainbows in the mind. Psychological Inquiry, 13, 249-275. ). The Hope scale includes 4 items for each of these components (Snyder et al., 1991 xClose
Snyder, C. R., Harris, C., Anderson, J. R., Holleran, S. A., Irving, L. M., Sigmon, S. T., Yoshinobu, L., Gibb, J., Langelle, C., & Harney, P. (1991). The will and the ways: Development and validation of an individual-differences measure of hope. Journal of Personality and Social Psychology, 60, 570-585. ). Agency is conceptualized as almost the same as perceived self-efficacy although the scale items are somewhat ambiguous. Pathways resemble outcome expectancies. (See contribution by Carver).

Health Locus of Control

According to Rotter's (1966) xClose
Rotter, J. B. (1966). Generalized expectancies for internal versus external control of reinforcement. Psychological Monographs, 80, No. 609. social learning theory, people may have either an internal or an external locus of control, often abbreviated as the I/E-dimension. The level of generality or situation specificity of this construct can vary. The research team of K. A. Wallston deserves the acclaim to have applied successfully Rotter's basic idea to the health domain. This domain specificity may be regarded as a medium level of generality, constrained to the subjective interpretation of various phenomena such as health behaviors, health outcome, health care, etc. (Wallston, Wallston, & DeVellis, 1978 xClose
Wallston, K. A., Wallston, B. S., & DeVellis, R. F. (1978). Development of the Multidimensional Health Locus of Control (MHLC) scales. Health Education Monographs, 6, 160-170. ). The term "locus" refers to the location where control resides-either internal (I) to the individual (based on one's traits or behaviors) or external (E) to the individual (due to other forces or chance). There are two dimensions, I and E, and, obviously, it is possible to subdivide them further. For example, chance and powerful others are quite distinct subfactors of the E dimension. The construct of MHLC has been built upon this idea, and its corresponding measure, the MHLC scales, contain exactly these three subscales, one I dimension and two E dimensions, all of which are considered to be orthogonal (Wallston et al., 1978 xClose
Wallston, K. A., Wallston, B. S., & DeVellis, R. F. (1978). Development of the Multidimensional Health Locus of Control (MHLC) scales. Health Education Monographs, 6, 160-170. ). The measurement of MHLC refers to wide areas of functioning, health, and medical conditions (see Wallston et al., 1978 xClose
Wallston, K. A., Wallston, B. S., & DeVellis, R. F. (1978). Development of the Multidimensional Health Locus of Control (MHLC) scales. Health Education Monographs, 6, 160-170. ). This generality might also explain the lack of significant associations between the loci and specific measures of health status or health behaviors. According to implicit assumptions that form the background of many studies, a firm internal locus of control belief might promote better health or healthier behaviors. Self-efficacy, nevertheless, seems to be the more powerful construct when it comes to the prediction of health behaviors. Self-efficacy shares the internal locus of control, but is also behavioral and prospective.