How can we collect satisfactory answers in art appreciation experiment?

We have been studying the way of art appreciation. For the study we have conducted several experiments. Several results could be obtained. However, we have experienced some problems. One is for free descriptions, it is rather difficult to obtain sufficient number or size of answers from participants. Or it will take a lot of time to collect full free descriptions. Although we conducted the previous experiment to solve the question that "how will the value and preference of art be changed according to offered factors?" Then we conducted the experiment in order to determine which factor (information) will change the viewers' sense of value and preference of art in the art appreciation. In this paper, we will analyze the answers in the previous experiment to find which type of information or question could make participants write a sufficient size of free descriptions. In addition, we will discuss the problem in the context of IMDJ (Innovators Marketplace on Data Jackets).