The relative uniformity of organisation and practice is undoubtedly due to the influence of a booklet, written early in Christadelphian history by Robert Roberts, called "A Guide to the Formation and Conduct of Christadelphian Ecclesias". It recommends a basically democratic arrangement by which congregational members elect 'brothers' to arranging and serving duties, and includes guidelines for the organisation of committees, as well as conflict resolution between congregational members and between congregations. Christadelphians do not have paid ministers. Male members (and increasingly female in some places) are assessed by the congregation for their eligibility to teach and perform other duties, which are usually assigned on a rotation basis, as opposed to having a permanently appointed preacher. Congregational governance typically follows a democratic model, with an elected arranging committee for each individual ecclesia. This unpaid committee is responsible for the day-to-day running of the ecclesia and is answerable to the rest of the ecclesia's members.