Answer:
generation effect
Step-by-step explanation:
In psychology, the term Generation effect refers to the phenomenon by which information is better remembered if one person himself/herself generates the information (or reach the conclusion by themselves) rather than simply read the information from another source.
In this experiment, the participants from one group just read word pairs while the other ones had to fill in the blank letters of the second word pair with a word related to the first word (in other words, one group simply read the word pairs while the other one actively generated the second word pair based on the information they already had). Therefore, this is an example of Generation effect.