The phenomenon of the glass transition is an unresolved problem in condensed matter physics. Its prominent feature, the super-Arrhenius temperature dependence of the transport coefficients, remains a challenge to be described over the full temperature range. For a series of molecular glass formers, we combined τ($T$) collected from dielectric spectroscopy and dynamic light scattering covering a range 10${}^{-12}$ s < τ($T$) < 10${}^2$ s. Describing the dynamics in terms of an activation energy $E$($T$), we distinguish a high-temperature regime characterized by an Arrhenius law with a constant activation energy $E_{\infty }$ and a low-temperature regime for which $E_{\mathrm{coop}}$($T$) ≡ $E$($T$)–$E_{\infty }$ increases exponentially while cooling. A scaling is introduced, specifically $E_{\mathrm{coop}}$($T$)/$E_{\infty }$ ∝ exp[–λ($T$/$T_{\mathrm{A}}$–1)], where λ is a fragility parameter and $T_{\mathrm{A}}$ a reference temperature proportional to $E_{\infty }$. In order to describe τ($T$) still the attempt time ${\tau }_{\infty }$ has to be specified. Thus, a single interaction parameter $E_{\infty }$ describing the high-temperature regime together with λ controls the temperature dependence of low-temperature cooperative dynamics.

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