Data analysis is very important for a research project. If data are collected well but are analyzed badly, we will be likely to draw incorrect conclusions.
For example, let us imagine that we are analyzing the housing prices in a given area. We collect the price of every house in a neighborhood. Then, we take the mean of the prices and use it to describe the neighborhood. But let us imagine that there are many medium-priced houses and a few very expensive outliers. If this is the case, our mean will be much higher than our median would have been. The mean will then be a bad measure of central tendency. We might want to analyze the data by using a median or by using measures of dispersion such as standard deviation.
Thus, even after we collect data, we must be sure to find the proper statistics and analyze the data in proper way. Otherwise, we will not really understand the data we have collected.