On 2015 Apr 24, BSH Cancer Screening, Help-Seeking and Prevention Journal Club commented:

The HBRC journal club read Scherer et al’s paper with interest. While flu vaccination is not the focus of our work, using metaphors as a manipulation to increase the likelihood of a behaviour and the methods used to test the efficacy of doing so, resonated with our research team. Most of the group were unfamiliar with the metaphor literature and found the introduction to provide a useful summary of the field. The authors present a discussion of the role of risk perceptions and affect, but a more detailed discussion of how the two interact and their complexities might have provided a truer representation of the field.

The group liked that the authors attempt to measure whether participants were likely to move beyond intention (measuring participants’ desire to receive a reminder email to get a flu vaccination), without having to measure behaviour (which is difficult to do objectively). However, contrary to the authors, the finding that individuals who occasionally get a flu vaccine were more likely to request an email reminder was unsurprising to us because individuals who always get a flu vaccination seemingly do not need reminding. A further strength of the paper is that non-emotive metaphors were considered (the flu as a weed), as this helped dispel the suggestion that the effect was due to vividity or violence (as might be the case with metaphors such as ‘beast’ and ‘riot’). The group wondered if a virus could also be considered to be a metaphor, given its use in computing. Additionally, it may have been of interest if the vaccination itself was also part of the metaphor, for example the flu virus being described as a ‘weed’ and the flu vaccine as ‘weed killer’. In Hauser DJ, 2015 using congruent metaphors to describe an illness and the measure to prevent the illness increased behavioural intentions compared to just using a metaphor to describe the illness.

While metaphors may increase the vividness of the flu and encourage individuals to engage, the group were concerned about how use of metaphors to manipulate behaviour may not be congruent with informed decision making, instead being considered coercive. We disagreed with the authors suggestion that metaphors might have a use in decision aids, which we believe have a role in helping individuals make informed decisions and not swaying their opinion. We suggested that metaphors might be useful when the aim is to increase individuals’ understanding, rather than increasing intentions to engage in a behaviour. It may also be important to consider the unintended consequences of using metaphors, for example in the cancer field (the focus of our work), describing cancer as a battle may lead to suggestions that people who do not survive the disease did not fight hard enough. However, we acknowledge that metaphors are used ubiquitously in the media, which is difficult to control.

The group felt that flu vaccination was a complex example to choose to conduct these studies. Flu is a fairly common illness, which might result in participants having an accurate estimate of their risk of contracting the illness or how serious it is. This might explain why the manipulation did not affect the mediators in the main analysis. Individuals are likely to have existing beliefs about vaccination (for example, beliefs about side effects, effectiveness) and the benefits of vaccination might not always be obvious (the individual does not contract the flu - a non event and herd immunity benefiting the population). It would have been helpful to have been informed about the flu vaccination recommendations in the USA where the study was conducted. Cultural differences in how the flu is appraised, treated and prevented between countries might alter the effect of metaphors. For example, in the group’s opinion, the metaphor ‘beast’ was an exaggerated conceptualisation of the flu and felt removed from the actual consequences of the virus.

Study 3 was perceived by the group to be the most useful study of the paper as it used a validated measure of affect and a larger sample than Study 1. The ecological validity of studies 2 and 3 could have been increased if Study 1 had been a ‘think aloud’ study, whereby the authors could have gained a justification for the mediators of flu vaccination that were tested. The group thought that a strength of the studies is that the authors did consider the possible mediators of any effect of the metaphor. Other mediators that could have been considered include attitudes and a measurement of arousal (engagement). A ‘think aloud’ study might also help to ensure that metaphors are used appropriately, for example in Hauser DJ, 2015, use of an enemy metaphor reduced intentions for self-limiting cancer prevention behaviours (such as stopping smoking or limiting alcohol intake). The group also wondered how novel the ‘novel’ metaphors used in the studies actually were, something that pilot work could have investigated.

The group thought it was interesting that the findings were not wholly consistent across the studies reported and considered that this could have been a product of differences in the sample. The authors do not describe whether participants were randomised to each condition, and no baseline measurements were reported, both of these factors leave readers unclear about whether the sample was similar across each of the studies. It would also have been helpful to have a justification for the sample size chosen for each of the studies.

Scherer et al. present a novel paper, which has provided readers with examples of how to measure the impact of using metaphors to increase intentions to receive a flu vaccination. Future work in this field should consider conducting pilot work to ensure the topic, manipulation and measures used are relevant to the population of interest. We caution readers to consider the unintended consequences of using metaphors to manipulate behaviour, including concern about the ethical implications this might have.

Conflicts of interest We report no conflict of interests and note that the comments produced by the group are collective and not the opinion of any one individual.

On 2015 Apr 24, BSH Cancer Screening, Help-Seeking and Prevention Journal Club commented:

The HBRC journal club read Scherer et al’s paper with interest. While flu vaccination is not the focus of our work, using metaphors as a manipulation to increase the likelihood of a behaviour and the methods used to test the efficacy of doing so, resonated with our research team. Most of the group were unfamiliar with the metaphor literature and found the introduction to provide a useful summary of the field. The authors present a discussion of the role of risk perceptions and affect, but a more detailed discussion of how the two interact and their complexities might have provided a truer representation of the field.

The group liked that the authors attempt to measure whether participants were likely to move beyond intention (measuring participants’ desire to receive a reminder email to get a flu vaccination), without having to measure behaviour (which is difficult to do objectively). However, contrary to the authors, the finding that individuals who occasionally get a flu vaccine were more likely to request an email reminder was unsurprising to us because individuals who always get a flu vaccination seemingly do not need reminding. A further strength of the paper is that non-emotive metaphors were considered (the flu as a weed), as this helped dispel the suggestion that the effect was due to vividity or violence (as might be the case with metaphors such as ‘beast’ and ‘riot’). The group wondered if a virus could also be considered to be a metaphor, given its use in computing. Additionally, it may have been of interest if the vaccination itself was also part of the metaphor, for example the flu virus being described as a ‘weed’ and the flu vaccine as ‘weed killer’. In Hauser DJ, 2015 using congruent metaphors to describe an illness and the measure to prevent the illness increased behavioural intentions compared to just using a metaphor to describe the illness.

While metaphors may increase the vividness of the flu and encourage individuals to engage, the group were concerned about how use of metaphors to manipulate behaviour may not be congruent with informed decision making, instead being considered coercive. We disagreed with the authors suggestion that metaphors might have a use in decision aids, which we believe have a role in helping individuals make informed decisions and not swaying their opinion. We suggested that metaphors might be useful when the aim is to increase individuals’ understanding, rather than increasing intentions to engage in a behaviour. It may also be important to consider the unintended consequences of using metaphors, for example in the cancer field (the focus of our work), describing cancer as a battle may lead to suggestions that people who do not survive the disease did not fight hard enough. However, we acknowledge that metaphors are used ubiquitously in the media, which is difficult to control.

The group felt that flu vaccination was a complex example to choose to conduct these studies. Flu is a fairly common illness, which might result in participants having an accurate estimate of their risk of contracting the illness or how serious it is. This might explain why the manipulation did not affect the mediators in the main analysis. Individuals are likely to have existing beliefs about vaccination (for example, beliefs about side effects, effectiveness) and the benefits of vaccination might not always be obvious (the individual does not contract the flu - a non event and herd immunity benefiting the population). It would have been helpful to have been informed about the flu vaccination recommendations in the USA where the study was conducted. Cultural differences in how the flu is appraised, treated and prevented between countries might alter the effect of metaphors. For example, in the group’s opinion, the metaphor ‘beast’ was an exaggerated conceptualisation of the flu and felt removed from the actual consequences of the virus.

Study 3 was perceived by the group to be the most useful study of the paper as it used a validated measure of affect and a larger sample than Study 1. The ecological validity of studies 2 and 3 could have been increased if Study 1 had been a ‘think aloud’ study, whereby the authors could have gained a justification for the mediators of flu vaccination that were tested. The group thought that a strength of the studies is that the authors did consider the possible mediators of any effect of the metaphor. Other mediators that could have been considered include attitudes and a measurement of arousal (engagement). A ‘think aloud’ study might also help to ensure that metaphors are used appropriately, for example in Hauser DJ, 2015, use of an enemy metaphor reduced intentions for self-limiting cancer prevention behaviours (such as stopping smoking or limiting alcohol intake). The group also wondered how novel the ‘novel’ metaphors used in the studies actually were, something that pilot work could have investigated.

The group thought it was interesting that the findings were not wholly consistent across the studies reported and considered that this could have been a product of differences in the sample. The authors do not describe whether participants were randomised to each condition, and no baseline measurements were reported, both of these factors leave readers unclear about whether the sample was similar across each of the studies. It would also have been helpful to have a justification for the sample size chosen for each of the studies.

Scherer et al. present a novel paper, which has provided readers with examples of how to measure the impact of using metaphors to increase intentions to receive a flu vaccination. Future work in this field should consider conducting pilot work to ensure the topic, manipulation and measures used are relevant to the population of interest. We caution readers to consider the unintended consequences of using metaphors to manipulate behaviour, including concern about the ethical implications this might have.

Conflicts of interest We report no conflict of interests and note that the comments produced by the group are collective and not the opinion of any one individual.