The fourth approach addressed the variation in villagers' responses, within villages, to questions about orangutans; it was acknowledged that the interpretation of these results was limited, since it was expected that even within the same village, respondents would have different propensities to encounter orangutans or simply differ randomly.
Outliers often disappear from figures (e.g., telltale sign are n's differing randomly between arms).
Researchers should also justify their selection of what Rubin termed "key covariates" and ensure that they only differ randomly between control and treatment groups.
RCM also rests on the important concept of "key covariates," or relevant variables that could explain pre-existing differences between the treatment and control conditions and that can be used to ensure that the distribution of these variables only differ randomly between the two groups one of the crucial conditions to make causal inferences.
Based on this variability, which allows the hospitals to differ randomly in intercept and slope from the baseline intercept and slope, the hospitals are located in four quadrants in the figure of the effects (see Figure 2).
To perform a causal analysis in the case of UK admissions to medical degrees we replicated an experimental design for two groups of applicants that differed only randomly on background characteristics, except that one group attended private schools and the other did not [ 8, 9].
First, and most obviously, there are only four MA lines, and it is certainly possible that for some reason gene expression in those lines differs randomly from the true MA mean.
Within the context of grain boundary engineering, where grain boundaries are classified as special vs. general, grain boundary networks are known to have non-random topologies and percolation thresholds which differ from randomly assembled networks.
Alleles associated with genetic disease differ from randomly selected HapMap alleles and neutral expectations.
Gene expression can differ seemingly randomly in amplitude, frequency and timing between genetically identical cells.
