 However, arguably, it is the most critical type of fragmentation, as studies have found that the most frequently accessed files tend to be small compared to available disk throughput per second.To avoid related file fragmentation and improve locality of reference (in this case called "file contiguity"), assumptions or active observations about the operation of applications have to be made.A very frequent assumption made is that it is worthwhile to keep smaller files within a single directory together, and lay them out in the natural file system order.