When designing an electoral system, it is best to start with a list of criteria which sum up what you want to achieve, what you want to avoid and, in a broad sense, what you want your legislature and executive government to look like. The criteria which follow cover many areas, but the list is not exhaustive, and the reader may add a host of equally valid items. It is also true that some of the criteria outlined overlap and may appear contradictory. This is because they often are contradictory: it is the nature of institutional design that trade-offs have to be made between a number of competing desires and objectives. These files focus primarily on criteria for the systems and not on the design process itself. The design process is covered in more depth in the sections Process of Change and Advice for Electoral Systems' Designers.
For example, one may want to provide the opportunity for independent candidates to be elected, and at the same time to encourage the growth of strong political parties. Or electoral system designers may think it wise to craft a system which gives voters a wide degree of choice between candidates and parties, but this may make for a complicated ballot paper which causes difficulties for less-educated voters. The trick in choosing (or reforming) an electoral system is to prioritize the criteria that are most important and then assess which electoral system, or combination of systems, best maximizes the attainment of these objectives.
