This can be done easily by studying the rollover in correlation with the cost of carry; however remember to use this tool in correlation with other tools as explained in the procedure to become a technical analyst here.
Rollover is the process of carrying over a futures position from one contract period to the next. This is done by closing the existing position and entering into a similar position for the next series. A high rollover percentage is taken as an indicator of the strength in the market sentiment.
Rollover data combined with the cost of carry is used as an indicator of market direction. High rollover with increasing cost of carry is bullish while high rollover with the declining cost of carry or the basis turning negative is a bearish indicator.
DO not jump to conclusion just by seeing the rollover data and cost of carry as high interest rate can be one of the criterion when cost of carry may be high and thus it has to be seen in light of numerous other factors also.