Credit this: how the banks decide your credit score

In February, internet bank Egg announced its decision to cancel the credit cards of 161 000 of its customers. Egg were "not comfortable with the level of risk" that these customers represented. Bank customers are judged by their credit scores. So what is credit scoring? How do lenders assess your creditworthiness? And how can you improve your credit score with them? David Edelman provides some answers.