Here is another simple exercise anyone can use. its great because it generates unlimited amounts of data for you to back test over, practice on, evaluate a system, or just look at. The reason why this method which is a spin off of what Tuschar Chande does is because it uses the entire range of data you set instead of random sampling. With random sampling you could resample moves, here each move is only used once. Also this does a lot of the same work as my data mining system. It maintains the same distribution of movement as the market actually had over that period, even though it is using a randomize that is normal in distribution. So if you ever wanted more practice on a single pair but have used all the historical data your provider gave you, you can generate more that will maintain that specifics markets personality.
Here is a picture of some real vs synthetic data I generated its the 1st 100 bars of a 15 minute chart.
You can see that in the synthetic price patter you still have, dojis, engulfing bars, quiet times as well as large range bars. This is a true test because if your system can still come out positive in this environment it is able to pick out something that is NON-RANDOM and there is no chance for you to curve fit, as you can recycle this data a million times and arrive at a million different price structures.
here a pic of the spreadsheet you can make it yourself its easy enough.
1) export and cut and paste the time and price data
2) calculate the differences between the OHLC of the bar to the C of the previous bar
3) copy values and add rand() function
4) sort values by rand() column
5) use the close of the 1st candle of real data as reference, calculate new bars based on the scrambled movements
6) save and format to be imported in to the charting package.
ps: I got the spreadsheet layout from a different forum. I just thought I would share it, but i cant link it.