Where a decision has an impact on the administration, the practical effect will depend on the nature of the decision, and the ease with which the public authority can respond to it. Particularly in the field of ‘structuring’, the principles of judicial review tend to be very flexible, varying their content with the context. As Professor Carol Harlow and Professor Richard Rawlings have pointed out, the flexibility of standards of ‘procedural fairness’ is essential if judicial attempts to fashion principles of general application to the whole of public administration are not to suffer from over- or under-inclusiveness, strangling administrators with impossible demands in some fields while giving inadequate protection to their clients in others; yet it adds to the uncertainty of judicial review, making it difficult for administrators to predict what is required of them, and so reducing the constrictive and useful role that judicial review can play in helping authorities to structure their own procedures.