Using population synthesis tools we create a synthetic Kepler Input Catalogue ( KIC ) and subject it to the Kepler Stellar Classification Program ( SCP ) method for determining stellar parameters such as the effective temperature T _ { eff } and surface gravity g .
We achieve a satisfactory match between the synthetic KIC and the real KIC in the \log g vs \log T _ { eff } diagram , while there is a significant difference between the actual physical stellar parameters and those derived by the SCP of the stars in the synthetic sample .
We find a median difference \Delta T _ { eff } = +500 K and \sim \Delta \log g = -0.2 dex for main-sequence stars , and \sim \Delta T _ { eff } = +50 K and \Delta \log g = -0.5 dex for giants , although there is a large variation across parameter space .
For a MS star the median difference in g would equate to a \sim 3 \% increase in stellar radius and a consequent \sim 3 \% overestimate of the radius for any transiting exoplanet .
We find no significant difference between \Delta T _ { eff } and \Delta \log g for single stars and the primary star in a binary system .
We also re-created the Kepler target selection method and found that the binary fraction is unchanged by the target selection .
Binaries are selected in similar proportions to single star systems ; the fraction of MS dwarfs in the sample increases from about 75 % to 80 % , and the giant star fraction decreases from 25 % to 20 % .