An experimenter wanted to test the effects of pleasant scents on learning by fourth grade children. To keep his work at a manageable level, he decided to introduce pleasant scents into the classroom...

An experimenter wanted to test the effects of pleasant scents on learning by fourth grade children. To keep his work at a manageable level, he decided to introduce pleasant scents into the classroom every afternoon for one week. No pleasant scents would be present during the morning hours. The experimenter chose the scent carefully – a lavender scent was chosen based on previous research. After the week of exposure to the pleasant scent, the children were given tests on the morning and afternoon material. Test scores for the morning material were much higher than the scores on the afternoon material. Thus, the experimenter concluded that pleasant scents disrupted learning in the classroom.What is the major problematic issue with this research?