A researcher is interested in the eventual divorce rates of people who live together before they get married compared to those who do not cohabitate before marriage. The researcher is particularly interested in the couples who cohabitate to see if cohabitation leads to higher divorce rates. In a sense, the couples who cohabitate are serving as the group.

acts of terrorism occur globally. the united nations global counter-terrorism strategy was created in order to build adequate systems of support and solidarity with victims of terrorism. here´s a summary of the proposed key themes: the importance of giving victims a face and a voice; protecting their dignity; giving victims legal status and defending their legal rights; providing victims with medical, psycho-social and financial support; building solidarity with victims; improving media coverage of victims; and focusing on the link between victims and counter-terrorism efforts more generally.

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.