I think this Wikipedia section summed it up really well for me: http://en.wikipedia.org/wiki/P-value#Alternating_coin_flips http://en.wikipedia.org/wiki/P-value

I think this Wikipedia section summed it up really well for me: http://en.wikipedia.org/wiki/P-value#Alternating_coin_flips http://en.wikipedia.org/wiki/P-value#Alternating_coin_flips Extreme example, but explains how the context can shift the findings significantly.