The purpose of this widget is to give you an overview of trending search queries and trending search queries that result in zero hits.
For each search query on the top lists you can see a short term trend score (ST) and a long term trend score (LT). The search queries with high ST-score are the ones that have been trending during the last days, whereas search queries with high LT-score have been trending during the last weeks. To be more exact:
The trend scores are sums of exponentially decayed event-counts. This is approximately equal to a floating average of number of events through the short or the long term. The short term is one week and the long term is three months. So a short term score of 1 indicates that a query has occured once every day through the last week and a long term score of 0.5 indicates that the query has occured on average 0.5 times per day during the last three months."