The phrase "although different methods have" is correct and usable in written English.
It can be used to introduce a contrast or exception regarding various methods in a discussion or argument.
Example: "Although different methods have been proposed, none have proven to be entirely effective."
Alternatives: "even though various techniques have" or "despite the fact that different approaches have".
Although different methods have been proposed to address these violations [30], the fact that patient violations significantly exceeded controls suggested that the model would be unreliable in documenting differences between patients and controls.
Although different methods have been trialed in medical education, memorizing is still an important step, especially for the basic sciences.
Although different methods have been proposed – using numbers, words, pictures or combinations – none has been extensively tested.
Although different methods have been used, there is important consistency between our study and those by Shiell et al, Ryan and San Miguel.
Although different methods have been used to distinguish between L5 pyramidal neuron subtypes, the correlation between electrophysiology, morphology, and projection targets allows a comparison between the various studies.
Although different methods have been used for poly(A) site prediction [ 10, 62], current methods achieve only moderate sensitivity and specificity.
Although many different methods have been proposed, the general form of the relationship between rainfall intensity and duration is: I=alpha {D}^{-beta } (1).
Although many different methods have been applied to clearly extract different SOC fractions, a deeper understanding is urgently needed to elucidate the kinetic properties of SOC fractions and their roles in controlling the magnitude of SOM mineralization.
There can be substantial inter-assay differences in performance between different 25-hydroxy vitamin-D platforms [ 46], although these different methods have acceptable correlation [ 32].
Although two different methods have been used for genetic transformation (biolistic for cv Svevo and Agrobacterium for cv Ofanto), the silencing of SBEIIa genes produced similar effects.
The differences between indices in this study, although not large, can be explained by the fact that different methods have different goals.
