Targeting these determinants can bring about change so it is useful to understand some of the behaviour change models and theories. The application of one model or theory does not preclude the use of another; there is often overlap.

1. The Health Belief Model proposes that the more a person feels vulnerable to a health threat and the more they perceive the threat as severe, the more likely they are to practise a protective behaviour. For example, if the fear of cholera is high, people are more likely to follow recommendations to protect their water sources. The actual choice of behaviour depends on the anticipated benefits of the behaviour and the associated costs/efforts. 
2. The Protection Motivation Theory provides an explanation of why and how individuals manage and make decisions under stressful situations. It describes why individuals decide whether a situation is harmful to them (e.g. their perception of risk of contracting COVID-19 or Ebola). It considers the rewards of continuing with risky behaviour as well as the consequences and costs of performing a health-protective behaviour. Similar to the Health Belief Model, the perception of the health threat depends on the perceived vulnerability to and severity of a health threat.
3. The Social Cognitive Theory introduces the concept of self-efficacy, which can be described as a person's confidence in being able to perform a particular behaviour. Self-efficacy is thought to predict behavioural performance directly and indirectly through its influence on intention B.4. For example, people may be aware of a water treatment method or of Oral Rehydration Solution to manage diarrhoea, but they may worry about getting the proportions wrong and lack the confidence to apply their knowledge. 
4. The Theory of Planned Behaviour and the extended Theory of Reasoned Action (figure below) describe people’s behaviour as dependent on personal beliefs that affect their attitude (and subsequently intention, B.5) towards practising a particular behaviour. An intention to act is also affected by the ‘perceived norms’ of behaviour in a given context. For example, how a person feels about using a shared latrine and whether others approve or disapprove of this practice B.6. It is also affected by ‘perceived behavioural control’ or the degree to which a person believes they are able to perform the behaviour (Ability and Self-Efficacy, B.4).

5. The Theory of Normative Conduct breaks down the construct of social norms into two components: (1) the individual's perception of the extent to which others perform behaviour and (2) the extent to which others expect that individual to perform the behaviour (perceived and actual norms). Both can be strong drivers  and barriers of hygiene behaviours B.6.
6. The Transtheoretical Model (also known as the Stages of Change Model, figure below) proposes that behaviour change (both positive and negative) occurs in six stages: Precontemplation, Contemplation, Preparation, Action, Maintenance and/or Cessation. People will be at different stages and need different information, support or interventions to move to the next stage. For example, a mother may already have considered (contemplated) using a potty to help manage her young child’s excreta and she may decide to buy one (preparation) but she may not yet have found the time or motivation to change her routine and use it (action). For most stages, time criteria for completion are suggested. The model also includes social-cognitive variables such as self-efficacy and action-outcome expectancy, which describe whether the behaviour is expected to lead to the results.

7. The Socio-Ecological Model (figure below) suggests that health behaviours are influenced by drivers and barriers at different levels (individual, family, community and structural); hygiene promotion (HP) activities should be targeted at these different levels to effect change. For example, to introduce a new water treatment method, HP activities may aim to increase a person’s confidence (or self-efficacy) and to make the method a ‘new normal’ in the community. Advocacy may also be necessary to promote the method in the WASH department. The theory provides a meta-model for social and behavioural change  

8. The Behavioural Drivers Model aims to build on the socio-ecological model and similarly clusters motivators and barriers of behaviour and behaviour change into psychological, sociological and environmental groups, but goes into significant detail about each factor. Psychological factors comprise, amongst others, interest and attitude B.5 and self-efficacy and intent B.4. Sociological factors include social influences and community dynamics. Environmental factors include the communication environment, defined as the information and opinions an individual is exposed to as well as emerging alternatives and structural barriers for behaviours.

Approaches such as FOAM F.19, COMBI F.18, RANAS F.20, ABCD F.16 and BCD F.17 also describe behaviour change models that incorporate many of the determinants outlined above.