Q. How consumer behaviour is effected by Beliefs?

The initial component is beliefs. A consumer may perhaps hold both positive beliefs toward an object (example coffee tastes good) as well as negative beliefs (example coffee is easily spilled and stains papers). Additionally some beliefs may perhaps be neutral (coffee is black) and some may be different in valance depending on the person or the situation (example coffee is hot and stimulates--good on a cold morning but not good on a hot summer evening when one wants to sleep). Note as well that the beliefs that consumers hold need not be accurate (example that pork contains little fat) as well as some beliefs may upon closer examination be contradictory (example that a historical figure was a good person but as well owned slaves).

Since a consumer holds numerous beliefs it may frequently be difficult to get down to a 'bottom line' overall belief about whether an object such as McDonald's is overall good or else bad.

That is for every belief we take the weight or significance (Wi) of that belief as well as multiply it with its evaluation (Xib). For instance a consumer believes that the taste of a beverage is fairly important or a 4 on a scale from 1 to 7. He or she considers that coffee tastes very good or a 6 on a scale from 1 to 7. Therefore the product here is 4(6)=24. Alternatively he or she believes that the potential of a drink to stain is extremely important (7) as well as coffee fares moderately badly at a score -4 on this attribute (ever since this is a  negative belief we now take negative numbers from -1 to -7 with -7 being worst). Therefore we now have 7(-4)=-28. Had these two viewpoint been the only beliefs the consumer held his or her total or aggregated attitude would have been 24+(-28)=-4. In practice of course consumers tend to have several more beliefs that must each be added to obtain an precise measurement.