Research into LTM duration

• Research into LTM duration was conducted by

  -Bahrick et al (1975)

  -he used 392 ppts aged between 17-74. High school yearbooks were obtained.

  -Recall was tested in various ways such as photo recognition and free recall
• ppts tested within 15 yrs of graduation had

  -90% accuracy for photo recognition

  -after 48 yrs recall declined to 70%
• free recall was

  -60% after 15 years and 30% after 48 yrs