premise: One in seven couples in the UK experience infertility . Unexplained infertility affects a quarter of these couples and common interventions to help them have been used for many years in line with fertility guidelines issued by the National Institute for Health and Clinical Excellence ( NICE ) . A team of researchers led by the University of Aberdeen compared the effectiveness of two specific interventions with expectant management ( no treatment ) . They recruited 580 women who had experienced unexplained infertility for more than two years from four teaching hospitals and a district general hospital in Scotland . What would be the value in recruiting that many women ?
hypothesis: The studies are more likely to render good and diverse results