Even with this limited data (the Internet was one-way at the time; all we could look at were "clicks") and the limitations of computing power, the value created from the data was substantial.
Figure 2 shows the Secchi depth during June to August in the Gulf of Finland since year 1900, and regression analysis, a t-test and a non-parametric test all showed that the Secchi depth has decreased significantly over time, although the variability of the data was substantial.
Even for two exposures, statistical power is limited for detecting interactions, and the value of β3 is estimated with limited precision, unless the data are substantial or there is particularly strong synergism (Greenland 1983; Rothman et al. 2008).
However, given that the amount of imputed data is substantial, we can never completely rule out the possibility of remaining bias caused by differences in the unobserved/unmeasured characteristics that are also associated with FPG at follow-up.
Allison ([2002]) demonstrated that even in the case of MCAR, dummy-variable adjustment may lead to biased estimates in ordinary least squares regression when the proportion of missing data is substantial (i.e., 50%).
Limitations: The number of patients excluded from the study due to missing data is substantial.
If the proportion of missing primary data is substantial (more than 10%) a series of sensitivity analyses will be carried out to determine the likely effects of missing data [ 99- 101].
However, the effort required to compile and process these detailed data is substantial, and presents a major barrier to more widespread adoption.
However, the discrepancy between the accuracy of IDEM as assessed by synthetic data vs. real expression, methylation and knockdown data is substantial.
Although variation in the reported DOC flux data was substantial between organic and mineral soils systems (60%), the limitations of the available data mean that it is not possible to test whether this is a systematic difference.
The findings demonstrated that the distribution and impact of missing data were substantial and that the pattern of missing data was unlikely to be 'missing at random'.
