As you may see, the volume based technical analysis sometimes could be very easy and in some cases it could be very complicated. As a rule it is easier to analyze volume on the longer term-periods and it is easier to define support levels. On the longer term charts and at support levels volume surges are stronger and more noticeable. Yet, when it comes to the shorter term charts and defining resistance levels volume based technical analysis becomes more complicated: volume surges are not as clear in the resistance as they are in support, and with smaller timeframes you have to consult higher timeframes charts to see general market trend and analyze volume in accordance to it. The same principles should be applied not just to volume but to any technical indicators. The difference between volume and price based technical analysis is that the volume shows the market sentiment that is based on the money flow, while price indicators rather follow the event. Volume never lie, yet, traders do mistakes in analyzing it. I'm not stating that the volume is the best technical indicator. It is difficult and sometimes almost impossible to apply volume analysis to low trading stocks. That is why volume works best with indexes.
Now, after the strong rally it is logical to ask if the market will continue to recover. There is no doubt that over the last couple of sessions the market could be considered overbought at least in short-term. Yes, if we take a look at 1-year and higher timeframe charts we may see that the stock market is still heavily oversold (especially DJI sector, then S&P 500 sector while Nasdaq 100 companies are less oversold). However, when you go to the lower timeframes you start to see some indications of overbought market. From this I would assume that the market still has power and most likely will go higher, however, price does not move up all the time - it moves up by having corrections down time on time. Taking look at the smaller time-frame charts I may see that we could be looking forward if not for a correction then at least for slow down and flat market.
I think everybody now believe that March 6, 2009 has market very strong support level due to the volume output in period from January 20, 2009 until now. I do not think we will see index back at this levels very soon. It is too early to judge if this is the end of the recession - it is not something that should be done after four positive sessions. Yet, I think we could expect good market over the next couple of month.