Comparing Random Allocation and Allocation by Preference to Mindfulness Practice

The goal of this randomized controlled study is to examine whether allocation based on preference to one of two brief mindfulness meditation practices (mindfulness of the breath or mindfulness of sounds) influences the potentially beneficial effects of these practices, and influences participants' intention to engage in further mindfulness practice. To the end, members of the general public will be randomly assigned to one of three groups: (1) a group in which they choose which of the two mindfulness practices they do; (2) a group in which they are randomly allocated to do one of the mindfulness practices; and (3) a control group that listens to an audiobook extract. The level of mindfulness of each group will be compared, along with some other outcomes.

The study will be an online administered experimental 3x2x3 design, with between-participant factor group (allocated to mindfulness practice based on preference vs. randomly allocated to mindfulness practice vs. audiobook control); a between-participant factor of practice type (mindfulness of the breath vs. mindfulness of sounds), which will be a dummy variable for the control group; and a within-participant factor of time (baseline vs. post-allocation vs. post-intervention). Participants in the 'preference group' will choose which of two mindfulness meditation practices (mindfulness of the breath or mindfulness of sounds) to undertake based on a brief description. Participants in the 'random allocation' group will be allocated to one of the two mindfulness practices at random, and participants in the control group will listen to an excerpt from an audiobook of an equivalent length of time. The primary outcome, state mindfulness, will be measured at all three time-points, as will positive and negative mood. Practice quality and intentional to engage in future mindfulness practice will be measured at post-intervention only. The following hypotheses will be tested: H1: Both the allocation by preference and random allocation groups will show greater improvement than the control group on both the primary outcome (baseline to post-intervention change in state mindfulness) and all the secondary outcomes, with the exception of practice quality (which is not applicable for the control group). H2: The allocation by preference group will show better primary and secondary outcomes than the allocation by random group. H3: The difference between each mindfulness-practice group and the control group in baseline to post-intervention improvement in mood state will be statistically mediated by baseline to post-intervention increase in state mindfulness. H4:The difference between the allocation by preference and random allocation groups in baseline to post-intervention change in mood state will be serially, statistically mediated by practice quality and baseline to post-intervention change in state mindfulness respectively, such that participants allocated to the preference group will show higher practice quality, which in turn will statistically predict greater improvement in mindfulness, which in turn will statistically predict greater improvement in mood state. H5: The same statistical mediation effects as described in H4 above will be observed when the outcome is self-reported intention to practice mindfulness in future, instead of mood state.