Table 1.

Categorisation of information message framing used in our review based upon the use of key persuasive communication principles.

Persuasive message category	Message Content
Use of probability framing and biased presentation of information	Framing probabilities as gain versus loss/Framing probabilities in absolute terms versus in relative terms – Selectively highlighting the most relevant information and downplaying the negative impact or vice-versa [For example, to emphasize financial loss from inaction rather than savings due to action or to highlight scarce actions as being valuable] [42,57]
Use of logical evidence and authoritative framing	Evidence can be factual assertions or quantitative information from credible sources such as recommended guidelines. [42,55] Provided by authority figures who can be experts/community members expected to have previous experience- eyewitness statements, testimonials, etc. [42,47,55]
Use of narrative framing	Stories and/or graphic images with an educational message that can transport audience to different psychological places [55]
Use of normative framing	Social norms [“rules and standards that are understood by members of a group, and that guide or constrain social behaviours without the force of law” [58] and are related to perceived social pressure to engage or not engage in specific behaviors [59]/Subjective norms.]- activated by providing social proof/validation [60] (i.e., by showing that social peers comply with proposed attitude/belief/behaviour) or by promoting the targeted behaviour through community members/block leaders/volunteers [61]; Personal norms [62] [“individuals' perception of their own moral obligations to perform a certain behaviour”] - related to ascribed responsibility/civic duty and environmental attitudes/ecological concerns. [41]; Perceived behavioural control- perceived control over opportunities and barriers to waste segregation behaviour- related to self-efficacy [63]/‘locus of control’ [64] (including the concepts of past-behaviour/habit; recycling competence), perceived convenience/effort including time, etc. [41,65]
Using emotional appeals	Dramatizing the evil and fear arousal/Guilt appeal/Focussing on positive emotions [42,55]
Reciprocation	Providing small unconditional amenities/gifts for “sunk cost” effect [66,67] before intervention (excluding interventions which specifically refer to such provision as ‘incentive’), showing concern for participants' problems and offering relevant solutions (Empathy-inducing framing) [42,47]
Decisional control and commitment–consistency mechanism	Allows participant to voluntarily decide compliance (with or without commitment- i.e., verbal/written declarations of intention- made in public or otherwise) which has higher probability of consistency/sustainable behaviour. Under this category, participants are often provided manipulative persuasive messages such as illusion of control (where there is none); one option implicitly taged along with another; small request followed by bigger (Foot-in-the-door technique - FITD); etc. [42,47]