The differences may limit the validity of international comparisons of unemployment data. See the examples for some specific comparisons. Comparisons between LMWHs prepared by similar processes vary. The authors noted various problems in doing the comparisons including infrequent data points. This complexity is optimal in terms of the number of comparisons. This will lead to errors in subsequent calculations or experimental comparisons. There are many ways to make relative comparisons between toxic substances. Thus, analogy can mislead if not all relevant comparisons are made. These successes led to favorable comparisons with Jackson. This allows for meaningful comparisons between different assemblies. See for motivation, examples, comparisons. These make direct comparisons between basins difficult. Data dredging is an example of disregarding the multiple comparisons problem. They enable unambiguous comparisons between measurements. Commercial sources also provide information that is invaluable for making comparisons.