Other examples are how to ride a bike, how tight to make a bandage, or knowing whether a senior surgeon feels an intern may be ready to learn the intricacies of surgery; this can only be learned through personal experimentation. Collins showed[14] that Western laboratories long had difficulties in successfully replicating an experiment (in this case, measuring the quality, Q, factors of sapphire) which the team led by Vladimir Braginsky at Moscow State University had been conducting for twenty years. Western scientists became suspicious of the Russian results and it was only when Russian and Western scientists conducted the measurements collaboratively that the trust was reestablished.