"Clear linkage" refers to a strong and direct connection between two things or ideas, where it is easily understandable how they are related or linked together. Full definition
One study, [18] based on Centres for Disease Control data, established clear linkages between birth control (the pill, the Depo - Provera shot and condoms) and increases in sexually transmitted diseases («STD «or «STDs»). (faith.org.uk)
In this way these theologians are taking up the challenge which Wesley and Edwards faced: to show the centrality of the affections in the Christian life while also making clear the linkages among emotion, belief and action. (religion-online.org)
Approaches such as breaking larger schools down into smaller learning communities and other comprehensive reform approaches, creating alternative school programs, and developing clear linkages to career skills and employment. (doe.virginia.gov)