Social media platforms are beginning to acknowledge these problems and deploy countermeasures, although their effectiveness is hard to evaluate11,25,35.
Some schools have tried to head off misbehavior by holding antiviolence workshops or enacting tougher punishments, but their effectiveness is hard to judge.
While caregivers and academics believe that such environments help dementia patients cope better, solid evidence for their long-lasting effectiveness is hard to come by, in part because the condition has no cure.
While most tobacco researchers agree that age restrictions will do no harm and may well help reduce the incidence of smoking among teenagers, firm scientific proof for their effectiveness is hard to come by.
Recent studies have demonstrated the effectiveness of hard c-means (k-means) clustering algorithm in this domain.
Reviewing the series, Wisden editor Sydney Southerton wrote, "Verity, apart from his one amazing performance at Lord's, could be complimented upon his steadiness rather than upon his effectiveness on hard wickets".
15 16 20 21 Despite the proven effectiveness of hard-hitting mass media campaigns, only 10 countries in the WHO African region reported having had at least one national anti-tobacco mass media campaign during 2009 2010.
Additionally, by not paying its compelled workers a fair day's pay for a fair day's work, the scheme sets up a parallel employment economy that threatens, for cost-effectiveness, the hard-won award conditions of external workers in comparable and legitimate jobs.
Conclusive evidence of its effectiveness has proved hard to establish.
As the size of your opponent approaches scary big, the effectiveness of a hard block tends toward zero.
