• A high detection significance for a particular chemical species does not indicate that its abundance is constrained accurately . For instance , retrieving on JWST / NIRSpec PRISM observations obtained with the Tiberius pipeline leads to a ∼25σ detection significance . However , on supplementing these observations with HST / WFC3 G141 and G102 data , the retrieved mixing ratio estimate is 1 dex higher , as the retrieval finds a different spectral baseline .