to be delivered through).<sup>14</sup> The sample comprised mostly poor rural households, with women’s mean age of 37 and a median of 4 years of schooling.

For the measurement experiment, individual respondents were randomly assigned to answer two experimental questions using one of the three survey methods: face-to-face, ACASI, or list experiment. The sample was equally split across the three groups.

The two experimental questions were asked approximately one hour into the survey, immediately after ACASI-administered questions from the modified Conflict Tactics Scale about all respondents’ experiences of IPV in the past 12 months (for women), and the likelihood of becoming violent in a set of hypothetical circumstances (for men).<sup>15</sup> Respondents were then asked the experimental questions according to the method they were assigned. The questions were: Women:

1. In the past 12 months, has your husband pushed or thrown you against something like a wall or piece of furniture?

2. Has someone other than your current husband ever forced you to have sex with them when you did not want to?

Men:

1. In the past 12 months, have you tried to limit your wife’s contact with her family?

2. In the past 12 months, have you threatened to hurt your wife or someone close to her?

The surveys were administered by enumerators the same sex as the respondent, in private settings where interviews could not be overheard. Most surveys were conducted in empty school classrooms, with one enumerator and one respondent per classroom.<sup>16</sup> The empty classroom interview sites afforded a more private setting than is achieved in many DHS and other household survey settings. Therefore, if a lack of privacy causes women to underreport, then the prevalence differences seen in this more private study setting between face-to-face and the two more private methods are likely to be smaller than the differences that might be observed in standard interview settings.

> 14Sectors are administrative units two levels below province, and 2 levels above village. Within the selected sectors, existing VSLAs were identified in 128 villages. The researchers ruled out 30 villages with fewer than three VSLAs each, and villages that were very close. This was done to minimize the risk of cross-village contamination for the separate randomized controlled trial, detailed in the RCT pre-analysis plan (Alik-Lagrange et al., 2017). Within the 98 study villages, the final sample included 2,042 intervention-eligible couples where at least one partner was a member of a VSLA, and 686 couples who were community members selected at random from a village household roster and who were ineligible for the intervention. VSLA couples’ treatment status was assigned by the research team only after baseline surveys were completed. Assignment was based on their ranking in a public lottery process that they applied to. The intervention, called ‘Indashyikirwa 2’, is a weekly couples group discussion that encourages couples to question traditional gender norms and build communication skills. Data were collected from December 2017 to February 2018.

> 15When all respondents reached the main section on IPV (which was to be asked through ACASI), they were shown how to use the ACASI module on the tablet and then instructed through practice questions. After the enumerator was satisfied that the respondent could use ACASI, respondents were left to answer the module while the enumerator stood approximately 5 meters away. Over 95% of female respondents and 98% of male respondents got the first ACASI practice question correct. After being assisted again, 99% of male and female respondents were able to answer the ACASI module in a way that maintained their privacy but with some support, for example, if they could not touch the tablet screens, they listened in the headphones and told the enumerator which button to select for them. The IPV ACASI questions asked of all respondents will be used in the randomized controlled trial. For men, the two experimental questions were the only IPV perpetration questions asked in the survey. The survey themes and order of questions are listed in Table A1 and Table A2.

> 16When classrooms were not available, surveys were conducted in empty offices, churches, or outside but strict privacy protocols were adhered to, including the requirement that interviews pause if someone else was within earshot or eyesight.

7