LOFTUS AND PALMER 1974

LOFTUS AND PALMER (1974)

EXPERIMENT 1

• 
• Bildunterschrift: WHATS THE VERB?

AIM

• TO INVESTIGATE HOW INFORMATION SUPPLIED AFTER AN EVENT CAN INFLUENCE THE MEMORY OF A WITNESS

HYPOTHESIS

• PARTICIPANTS WHO ARE ASKED THE SMASHED QUESTION WILL GIVE HIGHER MPH SPEED ESTIMATES THAN PARTICIPANTS WHO ARE ASKED THE HIT, BUMPED, CONTACTED OR COLLIDED QUESTIONS

METHOD AND DESIGN

• RESEARCH METHOD: LABORATORY EXPERIMENT
• INDEPENDANT VARIABLE: VERB USED IN CRITICAL QUESTION
• VERBS USED: SMASHED, BUMPED, CONTACTED, COLLIDED, HIT
• DEPENDANT VARIABLE: SPEED ESTIMATE IN MPH
• EXPERIMENTAL DESIGN: INDEPENDANT MEASURES

PARTICIPANTS

• 45 STUDENTS FROM AMERICAN UNIVERSITY
• SPLIT INTO 5 GROUPS OF 9 STUDENTS

PROCEDURE

• PARTICIPANTS WERE ASKED TO WATCH SEVEN VIDEO CLIPS ABOUT DIFFERENT CAR ACCIDENTS SOURCES FROM THE SEATTLE POLICE DEPARTMENT WHICH ALL LASTED BETWEEN FIVE AND THIRTY SECONDS
• THE VIDEOS SHOWED STAGED CRASHES BECAUSE OF THE ETHICAL ISSUES OF SHOWING REAL CRASHES
• THE SPEED THAT THE CARS IN THE CLIPS WERE TRAVELLING WAS KNOWN BY THE EXPERIMENTERS
• THE CLIPS WERE SHOWN TO THE GROUPS IN A COUNTERBALANCED ORDER TO REDUCE ORDER EFFECTS

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• PARTICIPANTS WERE EACH GIVEN A QUESTIONNAIRE IN WHICH THEY FIRST HAD TO GIVE AN ACCOUNT OF THE CLIP THEY HAD SEEN, AND THEN WERE ASKED SET QUESTIONS ABOUT THE EVENT ITSELF
• WITHIN THIS QUESTIONNAIRE WAS THE CRITICAL QUESTION: ABOUT HOW FAST WERE THE CARS GOING WHEN THEY ..... EACH OTHER
• THE VERB USED WERE HIT, BUMPED, COLLIDED, CONTACTED AND SMASHED
• THE EXPERIMENT LASTED ROUGHLY 90 MINUTES

RESULTS

• 
• FROM THE RESULTS TABLE WE CAN SEE THAT THE WORD 'SMASHED' GAVE THE HIGHEST MEAN SPEED ESTIMATE OF 40.8MPH AND THE VERB 'CONTACTED' GAVE THE LOWEST MEAN SPEED ESTIMATE OF 31.8MPH

EXPLANATION OF THE RESULTS

• FINDING OUT THAT CERTAIN VERBS CAUSED DIFFERENT SPEED ESTIMATES REALLY INTERESTED THE RESEARCHERS, THEY THOUGHT THAT THE RESULTS COULD BE DUE TO TWO REASONS AND THEY WANTED TO KNOW WHICH REASON WAS THE RIGHT ONE
• EITHER THE PARTICIPANTS WERE UNSURE AND THE VERB GIVEN BIASED THEIR RESPONSE IN A CERTAIN DIRECTION (KNOWN AS RESPONSE BIAS) OR, THE VERB CAUSED A CHANGE IN THE PARTICIPANTS' ACTUAL MEMORY, SO THEY SEE THE ACCIDENT AS MORE OR LESS SEVERE THAN IT ACTUALLY WAS IN THEIR HEAD WHEN REMEMBERING IT
• IN ORDER TO FIND OUT WHICH REASON WAS THE RIGHT ONE, THEY CONDUCTED ANOTHER EXPERIMENT...

EXPERIMENT 2

• 
• Bildunterschrift: SMASHED GLASS?

AIM

• THE SECOND STUDY WAS DESIGNED TO PROVIDE ADDITIONAL INSIGHT INTO THE SPEED ESTIMATE DIFFERENCES FOUND IN THE FIRST STUDY
• WERE THEY DUE TO A RESPONSE BIAS, OR HAD THE MEMORY ACTUALLY BEEN ALTERED?

HYPOTHESIS

• PARTICIPANTS THAT ARE ASKED THE SMASHED QUESTION WILL SAY YES MORE OFTEN TO SEEING BROKEN GLASS THAN THOSE THAT ARE ASKED THE HIT QUESTION

METHOD AND DESIGN

• RESEARCH METHOD: LABORATORY EXPERIMENT
• INDEPENDANT VARIABLE: VERB USED, SMASHED OR HIT
• DEPENDANT VARIABLE: SPEED ESTIMATES GIVEN IN MPH AND RESPONSE GIVEN AS TO WHETHER THEY RECALLED SEEING BROKEN GLASS
• EXPERIMENTAL DESIGN: INDEPENDANT MEASURES

PARTICIPANTS

• 150 STUDENTS FROM AMERICAN UNIVERSITY
• THREE GROUPS OF FIFTY STUDENTS, ONE GROUP SMASHED CONDITION, ONE GROUP HIT CONDITION, ONE GROUP CONTROL CONDITION

PROCEDURE

• THE PARTICIPANTS WERE ALLOCATED TO THREE CONDITIONS; SMASHED HIT OR CONTROL
• THEY WERE THEN SHOWN A VIDEO CLIP OF A MULTIPLE CAR ACCIDENT, THE CLIP LASTED FOR ONE MINUTE AND THE ACCIDENT PART LASTED FOUR SECONDS
• AFTER THE VIDEO CLIP THEY WERE ASKED TO COMPLETE A QUESTIONNAIRE, WHERE THEY WERE FIRST ASKED TO DESCRIBE THE ACCIDENT THEY HAD SEEN AND THEN ASKED A SERIES OF QUESTIONS ABOUT THE EVENT INCLUDING THE CRITICAL QUESTION: ABOUT HOW FAST WERE THE CARS GOING WHEN THEY ..... EACH OTHER?
• ONLY TWO VERBS WERE USED IN THIS STUDY, SMASHED AND HIT
• THE CONTROL GROUP WERE NOT ASKED THE CRITICAL QUESTION

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• A WEEK LATER, THE PARTICIPANTS RETURNED AND WERE ASKED TO FILL IN ANOTHER QUESTIONNAIRE BUT THIS TIME THEY WERE NOT SHOWN THE VIDEO CLIP
• THE QUESTIONNAIRE ASKED A SERIES OF 10 QUESTIONS AND THE NEW CRITICAL QUESTION WAS HIDDEN IN THIS LIST OF QUESTIONS AND THE CRITICAL QUESTION "DID YOU SEE ANY BROKEN GLASS?" WHICH WAS A CLOSED QUESTION AND PARTICIPANTS ANSWERED BY TICKING YES OR NO
• THE VIDEO DID NOT CONTAIN ANY BROKEN GLASS

RESULTS

• 
• THE RESULTS SHOWED THAT THE ESTIMATES OF SPEED IN MPH WERE AGAIN HIGHER WHEN THE WORD SMASHED WAS USED. THE SMASHED CONDITION HAD A MEAN OF 10.46MPH AND THE HIT CONDITION HAD A MEAN OF 8MPH. IN THE SMASHED CONDITION PARTICIPANTS WERE SIGNIFICANTLY MORE LIKELY TO RESPOND YES TO THE CRITICAL QUESTION IN THE SECOND QUESTIONNAIRE
• PARTICIPANTS WHO BELIEVED THE ACCIDENT TOOK PLACE AT A HIGHER SPEED (SMASHED), SAW TEH ACCIDENT AS MORE SEVERE AND WERE MORE LIKELY TO PRESUME THAT TEHRE HAD BEEN BROKEN GLASS, AND THIS MAKES SENSE AND IS WHAT WE EXPECT DURING FAST ACCIDENTS

CONCLUSION

• THE WAY A QUESTION IS ASKED WILL ENORMOUSLY INFLUENCE THE ANSWER THAT IS GIVEN
• INFORMATION OBTAINED DURING THE EVENT AND INFORMATION OBTAINED AFTER THE EVENT WILL INTEGRATE WITH EACH OTHER TO FORM 'ONE MEMORY'