A few years ago, I was thinking that it might be nice to distinguish wants as either essential or desirable. This would follow much common practice in, say, recruitment, when setting out the essential and desirable skills, qualities, abilities etc in a job specification.

However, on reflection, my sense is that it gains very little and complicates the interface a lot. It may even add uncertainty and confusion. If a criterion is labelled as desirable, do the results of an enquiry have that criterion or not? One has to look to see.

So, at least in this specification of RegenCHOICE, the distinction is not made. An answer to a question is either required or not. Users can easily swap requirements in and out, between required and considering, and see very clearly what results.

The way of working with this is, when you put in all your wants and there are no results, rethink some of your requirements as not essential, and drop them to considering. If, on the other hand, an enquiry receives many results, then include more desirable criteria to what is required until the number of results is in single figures.

• Required