What type of summary score did the teacher use when summarizing students' scores on identifying elements of the periodic table?

In the context of summarizing students' scores on identifying elements of the periodic table, the appropriate summary score type reflects how well students retain and recall the information regarding the elements. Retention scores indicate how much information students remember after a certain period, which aligns well with the task of identifying elements. This score focuses on the ability of students to maintain their knowledge over time, assessing their long-term memory and understanding of the periodic table.

Accuracy, while relevant in evaluating how correctly students identify elements, does not capture the overall retention aspect, which is critical for this question. Efficiency typically relates to how quickly tasks can be performed without compromising quality, and fluency addresses the smoothness and speed with which a task is executed. Neither of these factors specifically evaluates a student's ability to remember content over time in the same way that retention does. Thus, retention is the most fitting summary score for evaluating students' understanding and recall of the elements of the periodic table.