Human factors-pruning your program´s unused functions

The author cites a common finding of human factors research on software that about 10% of the functions account for almost 90% of the product´s use. She discusses the negative effect of having many features that are seldom used, namely: the product is (usually) more expensive; programs require more memory; the product is harder to use; the documentation is more bulky, which makes it more difficult to use; and the user interface may not be optimally designed. For software developers who want to optimize their programs by getting rid of useless features she describes three ways to find out what the users really need and actually use: task analysis, data logging, and surveys and interviews.<>