Nathan is doing a sociological study of people who have played professional sports. he interviews his subjects and then he observes them. whatever he is unable to ask or observe, he answers using his common sense. which of his steps is most threatening to the integrity of his study?

Janette goes into an electronics superstore to buy a new computer. the salesperson works with her to find the right model, and she agrees to buy a new computer for $500 and a floor-model 18-inch monitor for $100. just when she is ready to pay, the salesperson walks away for a minute and then comes back to inform her that the monitor she was ready to purchase can't be sold for < $125. she agrees to the extra $25 even though they had initially agreed on the $100 selling price. janette has fallen for the technique of gaining compliance.