There are still complaints that it is difficult to devise a survey that is appropriate for every institution.
Good, careful, and controlled field experiments are a relative rarity in political science; it's difficult to devise and execute rigorous studies outside of the laboratory.
Unfortunately, if you are not already holding such stocks, it is difficult to devise a trading strategy to profit from the seasonal pattern.
In fact, the recommendations on calcium are now so high that it is difficult to devise practical diets that meet them.
The truth is that it is difficult to devise a credible plan not merely to boost the lowest wages (a thorny enough problem) but to win a rise for the bulk of the workforce.
When comparing the performance of different compression methods, it is difficult to devise a comparison strategy between different compression methods that allows easy predictions since lossy compression performance and accuracy are in general highly data dependent.
Because the available file formats are proprietary, have limitations on the features they can reliably show, and use different atom labelling schemes from crystallographic programs, it is difficult to devise automated validation procedures, such as those in place for the crystallography.
Without knowledge of the causes of stigma and discrimination associated with TB, it is difficult to devise discrimination-reduction strategies that are likely to work.
While it is difficult to devise a statistical test for such a situation, biological intuition suggests that these may be meaningful.
Given the complexity of pre-integration and post-integration latency in HIV reservoirs, it is difficult to devise a strategy that can provide sustainable eradication of HIV from the reservoir sites, where most of the latent virus is concealed.
