Not to talk about the theory, only the methodology. Talking with the person in charge of the company is not as good as talking with the grassroots employees to get more information, such as the boss's private hobbies, whether there is a mistress, who is actually in charge of this company (previously encountered the company is actually the boss's mother's brother in charge of the situation) as well as some of the liabilities, which belongs to the side of the information to verify. Before the interview, must do the basic homework of the industry, know the industry's base profit margin, or you are fooled to death. For example, you must know the catering industry to know its peak season to know its gross profit margin of more than 80%, and even look at more reports are not as good as finding a weekend to go directly to the store to see the business or pick a day at night to close directly to the store to put the day's small ticket to count a little bit; apparel industry must know its go to the account period, seasonal clothing processing recycling process, the discount ratio; engineering industry must pay attention to the documents are complete, the entrance fee whether to pay full, how to calculate the settlement period, security is the case, and the project industry must be paid attention to. Payment period how to calculate, security is up to standard, there is no ready accident quota, or a project out of a few casualties on the money or delayed payment; production industry must know the rules of inventory, energy consumption and environmental protection is up to standard. For example, the grain production enterprises inventory calculation is not based on the volume of its warehouse to calculate, because the grain is not stacked full warehouse, will be bad. For example, the inventory of home appliance companies must be on time to count the loss, or lower discounts, because after a few months is a different price, computer devaluation is even more exaggerated. Talk less, listen more, the more you say the more likely to be wrong, catch the customer logic in the contradiction directly ask questions. Do not ask each other to answer yes or no questions, to ask open-ended questions, it is best to ask the kind of questions so that he opened his mouth is a large paragraph of the problem, such as their own views of the industry, the views of their peers, upstream and downstream business views and so on. You can catch him an answer to repeatedly change different questions to ask, for example, he said a year of pure income of 1000W, after you ask him the turnover, and then ask the profit margin, and then ask the turnover rate, and so on, once the heart calculates that the net profit is not 1000W, it is directly exposed to let him explain. Now basically every business has hidden liabilities, part of the joint insurance, depending on how much you can catch, this is a basic homework. For many companies, you look at his financial accounts is not as reliable as looking at his water, electricity and coal.