to think of what they have seen without being prompted for this information first

[keannu]

What does the 1 underlined mean? Does the information same as "ads" shown to them?
What does the 2 line mean? They only have to say "Oh, I've seen this in an ad"?

ex)One indicator of good advertising is the impression it makes on consumers. But how can this impact be measured? Two basic measures of impact are recognition and recall. In the typical recognition test, subjects are shown ads one at a time and asked if they have seen them before.In contrast, recall tests ask consumers to think of what they have seen without being prompted for this information first. Under some conditions, these two memory measures tend to yield the same results. However, recall tends to be more important in situations in which consumers do not have product data at their disposal, so they must rely on memory to generate this information. On the other hand, recognition is more likely to be an important factor in a store, where consumers are confronted with thoousands of products options and the task may simply be to recognize a familiar package.

[Ouisch]

In a typical "focus group" situation, test subjects are shown various advertisements and then they are asked about the commercial or print ad that they've just viewed. Their reactions/thoughts/opinions are recorded. A "recall test" as described in your first underlined example is one where the test subjects are not actually shown an advertisement, but are simply given the name of a product and then asked for their reactions/thoughts. The researchers are trying to see if the group answers this question with "Oh, yeah, that's the one with the commercial with the kids singing..." or "That's the beer with all those sexy girls in the magazine ads...." They are trying to determine which ads the subject has seen in the past have stuck in his memory.

Your second underlined passage explains the reason advertisers want to know the above. When a consumer is wandering the aisles at a grocery store and sees 20 different types of breakfast cereal on the shelves, each manufacturers is relying on the consumer to choose its brand. Whether consumers choose Wheaties because of the athletes on the front of the box, or Fruity Pebbles because they remember seeing the Flintstones featured in the TV commercials, manufacturers want to know what causes the consumer to choose a particular brand. They will then spend their advertising dollars accordingly.

[keannu]

In a typical "focus group" situation, test subjects are shown various advertisements and then they are asked about the commercial or print ad that they've just viewed. Their reactions/thoughts/opinions are recorded. A "recall test" as described in your first underlined example is one where the test subjects are not actually shown an advertisement, but are simply given the name of a product and then asked for their reactions/thoughts. The researchers are trying to see if the group answers this question with "Oh, yeah, that's the one with the commercial with the kids singing..." or "That's the beer with all those sexy girls in the magazine ads...." They are trying to determine which ads the subject has seen in the past have stuck in his memory.

Your second underlined passage explains the reason advertisers want to know the above. When a consumer is wandering the aisles at a grocery store and sees 20 different types of breakfast cereal on the shelves, each manufacturers is relying on the consumer to choose its brand. Whether consumers choose Wheaties because of the athletes on the front of the box, or Fruity Pebbles because they remember seeing the Flintstones featured in the TV commercials, manufacturers want to know what causes the consumer to choose a particular brand. They will then spend their advertising dollars accordingly.

Awesome!!! Thousands of thanks!!!! !!!