There is a big difference between day trading and other forms of trading like swing trading, position trading or active investing. The difference arises from the time frames used in day trading. All trades are cumpulsorily closed by a day trader, at the end of the trading session. Therefore, the day trader does not have the luxury of time. He cannot say to himself - ok, the trade is not working out, so let me wait. This is not possible because the trader is under a cumpulsion to end the trade by a certain time. So he cannot wait to find out if his trade is going to work out with more profits, or less losses.
My point is: day traders must be tuned to take profits at some point during the day. They must have sensible guidelines to exit. Day traders should therefore use profit targets, reversal patterns to close the trade. They should not continue with the trade hoping for more and more, because time is against them.