Originally posted on sharmanedit:
Below I summarise six measures of journal impact: the impact factor (IF), 5-year IF, Google Scholar Metrics, SCImago Journal Rank (SJR), Source Normalized Impact per Paper (SNIP) and Excellence in Research for Australia (ERA) ranking. As part of the research for this post I have found out the metrics (except 5-year IF) for a sample of 97 of the higher-impact biomedical journals and put them into a Google Docs spreadsheet, which can be viewed here (or on Google Docs directly here).
Most researchers get to know the IF fairly quickly when they start to read journals. So you probably know that an IF of 30 is high and that thousands of journals (the long tail) have IFs below 1. But fewer people have this kind of familiarity with the other metrics. So I have tried to estimate what range of numbers counts as ‘high impact’ for each metric. ‘High’ here means in the top 33% of my sample of 97 journals (already a high-impact sample).