help with test
I wonder if you guys can help me with a statistics problem I´m facing :
Regarding football(soccer for americans), there´s a common view that referees tend to compensate teams for when they´re called for a pennalty kick. Supposedly, when a referee calls a penalty kick against a team they are more likely to call a penalty kick for them later in the game. I have data for penalty kicks and wish to run a statistical test to check for that hypothesis. I tought that, comparing the the likelyhood of a penalty being called for a team, after a penalty had been scored against it would be a good reasoning. But theres a problem: when a team has a penalty called against, some time has already gone by and so there´s less time for a penalty to be called and, if the probability of a penalty being called can be assigned as a liner distribution over time, this would be a bias for the statiscal test --as an example if a penalty is called when there are only 5 minutes left(againt the 90 minutes full game)it would obviously be less likely that another pennalty happens. I then tought about using a variable, pennaltys by minute that would fix this problem : I would create a series of : pennalty for with earlier pennalty against per hour: as an example if a pennalty is called againt a team when there are 10 minutes left for the game and then a pennalty is called for that team, my variable would be assigned a value of 6(6 pennaltys per hour).
I´m not sure tough as how to compare this series with a series that would represent the average pennalty per game, I mean : whats the likelyhood of a pennalty to be called in a soccer game per hour? Shoul I create a series using the number of pennalty for game per minute and use an average ? If I do this, my sample for average game would contain thos with a pennalty for each side wich is my object of study an I think this would probably create a bias...
thank you very much
It seems what you want is average penalties per game PER TEAM, which is total penalties divided by 2.
Originally Posted by iancao
Sorry, but thats not it ; what I want is to measure if it is more likely for a penalty to be called for a team after a penalty has been scored against this team, than it woulb be the regular chance of a penalty being called.