The paper “Matching Faces to Photographs: Poor Performance in Eyewitness Memory” (Journal of Experimental Psychology: Applied [ 2008]: 364– 372) described an experiment to investigate whether people are more likely to recognize a face when they have seen an actor in person than when they have just seen a photograph of the actor. The paper states that there was no significant difference in the proportion of correct identifications for people who saw the actor in person and for those who only saw a photograph of the actor. In the context of this experiment, explain what it means to say that there is no significant difference in the group means.