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low energy transistions are the ones which are the most liable to be useful for understanding the behaviour of your material in "normal conditions"

in a terribly rough first approximation, the behaviour of your material is dominated by its first energy gap (HOMO - LUMO for instance) and therefore the interest in the low energy end of the spectrum

but other transistions are interesting too ...

it will depend of what you expect from your spectroscopy ; for instance, if you want to identify a material, you might need a full fledged spectroscopic signature !

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Thanks for the response @Fabrice. So you mean that low transitions are more important because they have the highest probability of occurring ?

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since they occur at lower energy levels, they are the most likely to happen

but once again, it depends of why your are performing a UV-IVS spectroscopy !

(and it applies to any analysis, by the way ...)

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It depends of what you expect from your spectra,and the performing of UV-Vis and NIR

spectroscopy