In this work, the authors used next-generation sequencing to detect editing events. They compared the obtained sequences (reads) with the genomic sequence. If the genome contained A but the read had G at the same position, they considered that an editing event.
However, this approach may overestimate the number of edits. First, the sequencing itself generates errors that can be mistakenly attributed to ADAR activity. Second, the gene may have many versions in a genome that differ at some positions, including A>G differences. This leads to some ambiguity in data interpretation.
To make up for these problems, several approaches have been suggested to detect inosine modification directly, including chemical modification and antibody-based enrichment. Post publication of this paper, newer techniques have been introduced that could be used for chemical modification.