Download Results (Raw data is in Appendix 4)

Examining the Effect
Effect of Leading Questions on Memory Recall
Examining the Effect of Leading Questions on Memory Recall
Session: May 2011
Candidate Name: Maung Pyay Phyo Oo
Session Candidate Number: 002120-007
IB Subject: Psychology HL
Word Count: 1837
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Examining the Effect
Abstract
The aim of the study was to determine the effect of certain words in a leading question on
memory recall. The study attempted to replicate Loftus and Palmer’s study in 1974, which tried
to show the flaws in eye-witness testimony. The words used in the leading questions were
“Smash, Contact, Accident” and they were replaced in the question, “Estimate the speed of the
car coming from the bottom when (they smashed/contacted)/(the accident occurred)”. Smash and
Contact were used because they were the maximum and minimum estimated speeds in Loftus
and Palmer 1974. Accident was used a s a control group. Subjects were asked to watch a video of
a car accident and then asked to answer questions on the video and one of them was the leading
question. The results indicated that the estimated speeds were in descending order from Contact,
Smash, Accident. The statistical tests showed these results were significant, but they were not
significant in the order that was expected, and were not able to show what had happened in the
original study.
Word count: 175
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Table of Contents
Introduction ............................................................................................................................................ 4
METHOD ................................................................................................................................................... 6
Design ................................................................................................................................................................... 6
Participants......................................................................................................................................................... 7
Material: ............................................................................................................................................................... 7
Procedure: ........................................................................................................................................................... 8
Results (Raw data is in Appendix 4) ............................................................................................... 8
Discussion of Results ........................................................................................................................... 9
Bibliography ......................................................................................................................................... 17
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Introduction
The cognitive level of psychology is based on the principles that human being s are information
processors who’s mental processes guide behavior, which can be studied scientifically and these are
influenced by social and cultural factors (Crane & Hannibal, 2009).
One of the cognitive processes that is studied is memory. Memory is remembering events, facts,
actions and emotions. Much of these are stored in the Long Term Memory, which is believed to last
indefinitely and potentially having an unlimited capacity. Although there is the Short Term Memory,
this only lasts up to approximately 30 seconds (Peterson & Peterson (1959)).
To process information as memory, 3 steps must be taken; encoding, storage, retrieval. These are
based on the Schema theory developed by Bartlett. Schema is defined as a mental representation of
knowledge. It is believed to influence the way memory is encoded and retrieved because schema
helps us simplify the details from our senses and also influences the retrieval as it can help serve as a
retrieval cue, the same way it helps encoding.
But this retrieval can sometimes create false memories. One of the pioneering studies of schemas
and false memories is Frederic Bartlett’s study in 1932 in which he used serial reproduction and
asked participants to retell a Native American story called The War of the Ghosts. The results
indicated that the story became shorter but was coherent even though certain details were omitted or
changed. The details that were changed were mainly from Native American culture, which suggested
that it was the participants’ schema that caused this change (Bartlett, 1932).
A more recent, significant study is Loftus and Palmer (1974), in which participants viewed a car
accident and were asked to estimate the speed of the cars. Each participant group was given different
words in the question, such as contacted, smashed, etc. Results indicated that certain words would
produce greater estimates than others. This was because words such as Smashed had a more violent
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schema than words such as contacted.
Both of these studies can be traced back to Gestalt Psychology. According to Gestalt theories,
humans tend to see or think ‘as a whole.’ Which means that instead of seeing or remembering
specific pieces of information, human are more inclined to remember the general outline (Boeree,
2000). One of the earliest examples of this can be seen in perception, where one can see different
objects based on their attitude (Appendix 1). This is called the foreground principle, introduced by
Edgar Rubin. Similar to this, in memory, people remember the whole. In Loftus and Palmer’s
experiment, the subjects generally remembered the speed of the cars but changed their attitudes due
to the trigger words and caused different estimates due to the experience they had with the trigger
words.
This kind of false or distorted memory is important because in the current justice system in many
areas of the world, eye-witness testimonies are used as a valuable source of information. But these
studies suggest the flaws in the reliability of such evidence due to schemas and guiding questions.
Because of this significance, I have decided to explore the effect of trigger words on memory.
Our aim is to examine the effect of leading questions on memory recall, specifically of the words
“smash, contact and accident” in estimating the speed of a car accident. For the schema of these
words, I will conduct the experiment in an international environment, instead of only to American
students to test its population validity. Similarly to the original study, I will show a video of a car
accident but to simplify the experiment, I will use the maximum and minimum speed estimated
words; contacted and smashed.
·
Null hypothesis – There will not be a significant difference in the estimated speeds of the
questions with Contact, Accident and Smash.
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Research Hypothesis – There will be a significant difference in the estimated speeds of the
questions with Contact, Accident and Smash.
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METHOD
Design
This study will use independent samples including one control group and two experimental
groups. The independent samples design was chosen to avoid the order effect because the independent
variable is a question (on speed) with a slight variation to the words used. So, if repeated measure was
used, the participants would find out the true aim of the study.
Some of the variables that will be controlled are standardizing the video that is shown, the
briefing and debriefing notes, and the location of the test to isolate the variable (the slight variation of the
word in the question on speed). During the briefing and debriefing, the same experimenter will do this for
all three groups with a pre-written script.
The study will have 3 different groups. The first group will be the control group, which will be
asked to estimate the speed of cars in a question without a verb (e.g. “How fast were the cars going when
the accident occurred?”). The experimental groups will be asked to estimate the speed with different
verbs for each groups (e.g. “How fast were the cars going when they smashed/contacted?”). The
independent variables in the experiment are the words that describe the accident “smashed” and
“contacted”. These two verbs were chosen because they were the words that made participants estimate
the maximum and minimum speeds. The controlled variable will be the “accident”, and this was chosen
as it is not a verb, like the independent variables. The dependent variable will be the speed of the car that
is estimated by the subjects (in kilometers per hour).
To follow the ethical guidelines, consent forms (Refer to appendix 1) will be sent out to
participants, with information on the ethical guidelines that the study will follow and some information
on the study itself. The participants will be thoroughly briefed before the video is shown. The
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participants will be allowed to withdraw at any time during the experiment. And after the experiment, I
will debrief the participants and make the results available for them.
Participants
The target population of the participants is the students above the age of 16 of K International
School Tokyo. This target is chosen because the study was to determine if Loftus’s effect could be
observed with teens (15-18 years old) but wanted to avoid the population validity of having US
participants, therefore, used an international school. Other than this, there were no specific characteristics
that the participants had to have, or not have. Opportunity samples were used for ease in conducting the
study. This was because having a random or stratified sample would make it very difficult to schedule a
time when all participants can be a part of the study. To divide the participants into the two treatment
groups, the groups were divided to have 8 participants in each group with 24 participants in total.
Material:
 Video clip consisting car crash from www.youtube.com on a public domain
 Consent form
 Questionnaires (Refer to Appendix 2)
 Script for experiment (Refer to Appendix 3)
 Briefing notes
 Debriefing notes
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Procedure:
1. Total of 30 students aged from 15 to 18 years old were given consent forms “4” days before the
experiment to complete in order to participate in the experiment.
2. The participants were all taken into a classroom where chairs and tables were set up in front of a
screen.
3. Participants were randomly given different types of questionnaires
4. All the participants were briefed at the same time using a script
5. The participants were shown a video clip consisting of a car accident
6. The participants were given two minutes to fill out a questionnaire
7. The questionnaires were collected in after two minutes
8. The participants were then debriefed using the script
9. The participants were thanked for their cooperation and released.
Results (Raw data is in Appendix 4)
Contact Accident Smash
MEAN
90.6
72.0
80.3
MEDIAN
80.0
60.0
80.0
STDEV
36.9
19.6
25.7
The data acquired from the experiment was a Interval Data and the experiment was conducted
using independent samples. Therefore, the T-Test was the appropriate test of inferential statistics.
The T-Test results between Contact and Smash gave a result of 0.557.
The P-Value result was 0.556.
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Results indicate that Contacti induced a higher estimated speed than Smash or Accident.
Measure of central tendency used in the graph is mean. This is because the data was too limited
for median and lacked recurring numbers for using mode.
The T-Value and P-Values suggest that the results are not significant, and therefore, I accept the
null hypothesis.
Discussion of Results
The findings suggest a different results from Loftus and Palmer in 1974 because the experiment
was unable to show that students estimated a higher speed for smash than contact and the results were not
significant. In fact, the findings show that Contact was higher than both Smash and Accident, which may
be cause by the flaws in the design and procedure of the experiment.
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The first flaw is the ability of the students to estimate speed. It is very unlikely that students from
15-18 have driven a car be fore and therefore lack the ability to estimate the speed. This may have caused
the students to estimate outrageous speeds for the cars.
The second flaw is the number of participants that were in the experiment. Because some students
failed to hand in consent forms back in time, there was a significantly less number of participants than
expected. So, this small sample may have caused a skewed result. A possible modification to this may be
to give out consent forms earlier and to follow up on the students before the experiment to return the
forms.
The third flaw is the length of the video. The video was only 12 seconds in length which may not
have been enough time for students encode into memory. This follows onto the fourth flaw, which is the
amount of time between the video and the question. Because it was only a short interval, the students
may not have had the chance to use the schema of the Smash or Contact. From observation, it seemed
that some students may have finished very early, which indicates a possibility that the car accident was
only in the students’ short term memory, which makes the schemas unnecessary. The possible
modification to the design is to have a longer video clip as well as a longer interval between the video
and the questions like Loftus and Palmer.
The fifth flaw is that some students did not know whether to answer in kmph or mph. This is a
cultural factor that must be taken into account when experimenting on cross-cultural groups. This may
cause a difference in the way people think of speed. A modification that can be made is to specify one
type of speed such as kmph, which is what I have used in Graph 1 so that it does not cause any confusion
between the students.
In conclusion, this study failed to support Loftus and Palmer (1974)’s study that the word
Smash induced a higher estimated speed from memory recall than Contact.
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Appendices
Appendix 1 – Consent Forms
Consent Form
Psychology Experiment – Maung Pyay Phyo Oo, Hikaru Takeuchi
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I have been informed about the nature of the experiment
I understand that I have the right to withdraw from the experiment at any time.
Any information or data about me will not be shared by anyone and will remain confidential.
My anonymity will be protected and respected as my name will not be identifiable.
The experiment will be conducted so that I will not be demeaned in any way.
I will be debriefed at the end and have the opportunity to find out the results.
I give my informed consent to participate in this experiment.
I have the right to request the results of the experiment
NAME_______________________________________________
DATE________________________________________________
Appendix 2 – Questionnaires
Questionnaire
Please write you answers in the space provided below the questions
1) Which way did the car involved in the accident come from? (Left, Right, Top, Bottom) Please choose
for both cars.
2) What time of the day was the accident?
3) Estimate the speed of the car coming from the bottom when they smashed.
Questionnaire
Please write you answers in the space provided below the questions
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1) Which way did the cars involved in the accident come from? (Left, Right, Top, Bottom) Please choose
for both cars.
2) What time of the day was the accident?
3) Estimate the speed of the car coming from the bottom when they contacted.
Questionnaire
Please write you answers in the space provided below the questions
1) Which way did the car involved in the accident come from? (Left, Right, Top, Bottom) Please choose
for both cars.
2) What time of the day was the accident?
3) Estimate the speed of the car coming from the bottom when the accident occurred.
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Appendix 3 – Script
Script:
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Thank you for participating in our experiment
You are here because you have accepted the consent form and are aware of what this experiment will
require you to do.
In this experiment, you will be shown a video of a car accident and following that, you will be asked
to complete a questionnaire consisting of 3 questions.
Please notify us now if you do not have any writing utensils.
During the course of this experiment, you may not communicate in any way with others around you.
After the experiment, you will be fully debriefed about the nature of the experiment
If, at any point during the experiment, you wish to withdraw from the experiment, please notify us.
Do you have any questions at this point?
You can also ask us questions at any point during the experiment
We will now begin the experiment by showing you a video
Play Video
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Now, please fill out the questionnaire given to you
Pass Out Questions
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You will have two minutes to complete this task
When you are finished, please wait quietly for the others to finish.
Again, please refrain from communicating with others around you
Finish 2 Minutes
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It has been two minutes, we will now collect in the questionnaires.
Collect Papers
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Now, the experiment is finished and we will debrief you.
Debrief
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The aim of the experiment was to test how memories can be manipulated through guiding questions.
This is part of the Cognitive Level of Analysis, which is related to understanding how thought
processes work. In this specific experiment, we tested if the words, “contacted, smashed, or accident”
would have any effect on the estimates you made of the speed of the cars. We expected the order of
the estimated speed from greatest to least as smashed, accident and contacted. This is believed to
happen because when somebody remembers something (create a memory), they do not remember
exactly what it is, but rather the big picture. This means that when you create a memory, it is
influenced by schema, which is the preexisting knowledge that you have. So, when we used the word
“smashed,’ this would have created a more violent memory than “contacted” because of the images
that these words would hold (smashed being more violent than contacted), making you estimate a
higher speed for smashed. The first two questions in the questionnaire were there so that you would
not answer the question on speed directly after viewing the video.
Your anonymity will be protected and the results will be strictly confidential
If you wish to withdraw your data from the results, you may notify us now
If you wish to receive a copy of the final report, please notify us now and give us your contact
information
You have now been fully debriefed about the experiment
Do you have any questions?
Thank you for participating in the experiment.
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Appendix 4 – Raw Data (kmph)
Contact
Accident
Smash
60.00
55.00
48.00
65.00
60.00
60.00
68.00
60.00
75.00
80.00
85.00
80.00
80.00
100.00
80.00
120.00
90.00
161.00
129.00
Appendix 5 –
Source: http://www.sapdesignguild.org/resources/optical_illusions/images/faces.gif
Appendix 6 – Video snapshots
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Appendix 7 – T-test
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Bibliography
Bartlett, F. (1932). Remembering: A Study in Experimental and Social Psychology. Cambridge
University Press.
Boeree, G. (2000). Gestalt Psychology. Retrieved October 14, 2010, from Shippensburg
University: http://webspace.ship.edu/cgboer/gestalt.html
Crane, J., & Hannibal, J. (2009). Psychology; Course Companion. Oxford: Oxford University
Press.
Loftus, E., & Palmer, J. (1974). Reconstruction of Automobile Destruction : A n Example of the
Interaction Between Language and Memory’. Journal of Verbal Learning and Verbal Behavior ,
13, 585-589.
Peterson, L., & Peterson, M. (1959). Short-term retention of individiual verbal items. Journal of
Experimental Psychology , 58, 193-198.
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