The standard errors are adjusted for the potential clustering of errors at the regional level.
The results indicated that a 96% cutoff clustering of error-rich reads and a 97% cutoff clustering of filter-passed reads gave the worse results than a 96% cutoff clustering of filter-passed and selected filter-passed reads (Supplementary Fig. S3).
Simulated non-uniform gradient flows and vortical flows with a noise distribution are added with simulated single or clusters of error vectors to evaluate the performance of the FADV scheme.
The communication systems and disk or tape memory can sometimes cause clusters of errors, namely burst errors.
As shown below, these OTUs represent clusters of errors derived from very abundant organisms in the underlying population.
However non-uniform clusters of errors indicate that they are not independent and therefore redundant scans may not resolve the problem.
All regressions utilize student fixed effects, robust standard errors, and clustering of standard errors by individual students.
Finally, in section Robustness, I analyze the robustness of my results to the inclusion of counties from neighboring non-expansion states, exclusion of county-specific time trends, and clustering of standard errors at state-level.
These results are robust to the inclusion of counties from neighboring non-expansion states, limiting the control group to only high-poverty counties from comparison states, exclusion of county-specific time trends, and clustering of standard errors at state-level.
However, this raises the issue of how to incorporate individual fixed effects in an ordered logit model; the choice between suggested alternative estimators is not straightforward and raises further difficulties relating to the clustering of standard errors in panel data.
However, as there is no clear best choice among the above estimators and relying on these would raise difficulties concerning the clustering of standard errors, we chose the above linear models as our preferred specification.
