The aim of the study was to determine whether leading questions would affect the memory of eyewitnesses at a real crime scene. In other words, the aim was the same as Loftus & Palmer's (1974) study, but in this case, the event that they observed was real and had an emotional impact on those that observed it.

The crime scene was in Vancouver. A thief entered a gun shop and tied up the owner before stealing money and guns from the shop. The owner freed himself, and thinking that the thief had escaped, went outside the shop. But the thief was still there and shot him twice. Police had been called and there was gunfire - and the thief was eventually killed. As the incident took place in front of the shop, there were eyewitnesses - 21 were interviewed by the police.

The researchers chose this incident to study because there were enough witnesses and there was forensic evidence available to confirm the stories of the eyewitnesses.

The researchers contacted the eyewitnesses four months after the event. 13 of the eyewitnesses agreed to be interviewed as part of a study. They gave their account of the incident, and then they were asked questions. Two leading questions were used. Half the group was asked if they saw "a" broken headlight on the getaway car. The other half were asked if they saw "the" broken headlight. In fact, there was no broken headlight. The second question asked half the group if they saw "the" yellow panel on the car, and the other half was asked if they saw "a" yellow panel on the car (the panel was actually blue). They were also asked to rate their stress on the day of the event on a seven-point scale.

It was found that eyewitnesses were actually very reliable. They recalled a large amount of accurate detail that could be confirmed by the original police reports. They also did not make errors as a result of the leading questions. 10 out of 13 of them said there was no broken headlight or yellow quarter panel, or that they had not noticed those particular details.

The researchers found that the accuracy of the witnesses compared to the original police reports was between 79% and 84%. It appears that this research contradicts the study by Loftus & Palmer (1974). It could be that the lack of emotional response to the video that was shown in their study played a key role in the influence of the leading questions.  The witnesses reported that they didn't remember feeling afraid during the incident, but they did report having an "adrenaline rush."

Even though this study was also done under lab conditions, the actual context of the experiment was naturalistic - that is, the even that they witnessed was naturally occurring and not manipulated by the researcher. However, it is not a natural experiment.  In a natural experiment, the IV (the leading question) would have to be manipulated by environmental forces beyond the control of the researcher.  In this study, the researchers manipulated the variable - which was the use of misleading questions.  The study does use a purposive sample - that is, the sample is chosen because they were eyewitnesses to the crime.  Only people that meet that requirement are eligible to be participants in this study.

There was archival evidence (police records of the original testimonies) to confirm the accuracy of the memories.

The study is not replicable and also not generalizable since it was a one-off incident. There was no control of variables, so it is difficult to know the level of rehearsal that was used by the different eyewitnesses.  It could be that those who agreed to be in the study had spent the most time thinking and reading about the case.

Because the eyewitnesses' safety was threatened, it could be that this is a case of flashbulb memory, which would mean that it cannot be directly compared to Loftus's original research.

There was an attempt at deceiving the participants.  As consent was given by all participants, the idea that undue stress or harm would be caused by being asked to recall the incident is unfounded.

The quantification of the qualitative responses from the participants is problematic and may be open to researcher bias.

The research method of this study is rather confusing.  Looking at many different websites, it appears that there is a lot of disagreement about what the research method actually is.  So, a few comments on this.

Some studies call this a "field experiment."  However, it is unclear how this would be the case.  The experimental part of this study was done under controlled conditions.  The confusion has to do with the nature of the sample. The researchers were taking advantage of a naturally occurring event (the crime) and used participants who were willing to undergo the experiment to see if the misinformation effect would occur. Although the study is experimental and done in a laboratory, ecological validity is high because, unlike Loftus and Palmer's study, there was an emotional reaction when the memory was created.

You could easily call this study an experiment. The participants were randomly allocated to conditions and given different levels of the IV.

However, you will notice that the study also carries out interviews with the participants and then compares the information from their interviews to the original police reports.  The research is focusing on a specific crime (or case) and uses method and data triangulation.  Thus, this could be considered a case study.  In fact, that is the research method that the researchers identify in their own publication of the study.

On the exam, you would focus on only the experimental part of the study and describe it as an experiment.  You could also explain that it is a case study, but you would have to include the interviews as well.