Becky Milne explains the cognitive interview

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Dr Becky Milne, Principal Lecturer at the Institute of Criminal Justice Studies at the University of Portsmouth, explains the technique of cognitive interviewing.

By: Dr Becky Milne (University of Portsmouth)

  • Duration 15 mins
  • Updated Friday 9th April 2010
  • Introductory level
  • Posted under Psychology
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Copyright The Open University


Becky Milne: The cognitive interview was developed for the interviewing of cooperative interviewees, be they witness, victim or suspect, and basically it’s a collection of tools, on a toolbelt that are trained to the police, and the tools on the toolbelt that are trained to the police all help to aid certain areas of memory. Now originally the cognitive interview consisted of four primary techniques.

The first technique is a simple technique. It’s simply telling the witness to tell me absolutely everything they can remember; don’t leave anything out, don’t edit anything. The reason why this simple technique basically to tell someone tell me everything is that we know that even the most cooperative adult does not spontaneously report everything that they remember. When they remember something, when they retrieve it, they make a decision, do I tell the person I’m talking to or do I withhold it? And so this simple technique of tell me everything stops witnesses and victims and suspects withholding information.

Now people may withhold information for a large number of reasons. One reason is they think well it’s not important information. But the general public do not know what’s of importance to the police. They might withhold information because they’re not sure about it, oh did I see that or did I not? And there’s lots of research looking at the correlation between how confident someone is and actually how accurate they are, and indeed confidence is instead a personality measure rather than an accuracy measure. Someone may withhold something because they feel well the police already know, they’ve interviewed other people, there was CCTV there.

But what we train the police to do is explain to every witness that when they are solving a crime they are piecing it together, every information they get, whether it’s from CCTV, whether it’s from other witnesses, whether it’s from the interview with a suspect, they piece all this information together like a jigsaw puzzle, and they basically try and make sense of all that information to try and find out the two key investigative questions, what happened and who done it. So just because an individual might believe the police to already know, it’s important for them to report it too because it might be the key final piece to that jigsaw puzzle, to solving what had happened. So the report everything instruction is very very very essential to getting the maximum quantity of detail from a witness or victim or suspect of a crime.

The second technique is what we call context reinstatement. This gets witnesses to think back in their mind’s eye the environment of where the crime actually occurred. It’s very much like you know if you’ve lost a set of keys or a pair of glasses and you’re trying to think in your head, you create an image of where you thought you last saw them, whether it’s your place of work, your home, and you try and think where was it, and you visualise that place in your head and you think of where the keys were. Very similar, what we try and do is we get our witness or victim to either close their eyes or look at the floor, we don’t want them to be too distracted, and we get them to create an image in their mind’s eye of that scene, and it’s quite easy to do, all we get them is to start thinking about things and we say some basic phrases.

We say for example I want you to close your eyes, get a clear, clear picture of the scene in your head. Think about everything that you can remember in that scene, get a clear picture of it. Think about the layout of the scene. Think about all the objects that were there. Think about all the colours that you can remember at the scene. Think about all the sounds that you remember hearing. Get a clear picture of all the people that were there, and then in your own time and in your own pace tell me everything you can remember about that scene. And that’s getting people to slow down, to think about the scene in their head and to create that image in their mind’s eye, and we know through research that is very helpful for memory retrieval.

Another of the basic four cognitive techniques is called the reverse the temporal order of recall technique, and this basically gets people to think about the event in a variety of ways. So we get people to either go backwards from the last thing they remember to the first or from the most memorable aspect of the event and going backwards and forwards in time.

Now the reason why this is important is that people from a very young age develop scripts in memory, and the primary reason we do that is because we dislike the unknown. Everyone has been in a situation where you’re going somewhere new, it may be a new place, a new restaurant, and you’re a bit unsure of what it’s like, so you ring someone up who’s been there before, what’s it like, how smart is smart, what are you wearing - that’s a typical fear of the unknown. And because we all fear the unknown, from the age of about three we start developing rules and regulations in life; what typically happens in a restaurant, what typically happens in a dentist. So people develop these scripts.

Now most crimes, which are one-off events, tend to be, unless it’s domestic violence or child abuse, but most crimes like a murder or an armed robbery, a bystander or a witness it’s a one-off event. However, these one-off events, which are what we call episodic memory, is embedded into someone’s routine and so therefore when we get people to report an event they might just report what normally happened on a day, what typically happened on a day, but what we really want them to do is remember what happened on the specific day. Rather than relying on their normal routines, we want to know exactly what happened on that particular day. And so getting someone to go backwards and from the most memorable aspect of the event and going backwards and forwards in time, it gets people to go back to that original memory of what actually occurred.

The reverse order recall instruction is also very useful for trying to detect deceit. Of course, unfortunately, within investigations people do lie, and there has been a whole body of research looking at methods of detecting deceit. Now when people lie they rehearse their lies and typically people will rehearse their lies in a chronological order, and therefore if we get someone to go backwards in time, this therefore really is tricky for someone who is lying, and so research by someone called Aldert Vrij, he has examined the use of the cognitive interview with people who are lying, and we find that it’s very difficult for people to lie when the cognitive interview is used in an interview scenario.

The final technique, the fourth one of the original four, is something called the changed perspectives technique. Now people again are also very egocentric, we’re very me-me-me-me-me, which is fine when you get a witness maybe of a very traumatic event to recall an event. You know, we have weapon focus effect and people are there, you know, going god this happened, that happened, and so of course understandably they report it from their own viewpoint, their own perspective. This technique, which is often used later on in the interview, gets people to think about the event from another perspective, so for someone else who was at the scene.

For example, you get people to think about the event in the shoes of, it’s almost like they’re in a spotlight, and you get that person to isolate that particular memory about the person with the gun, like they’re in a spotlight on the stage, and we just want them to report everything they remember about that particular individual, and this gets people to start thinking about putting themselves in the shoes of another individual at the scene, maybe even the perpetrator, although it does depend on how traumatising and the type of event.

For example, we wouldn’t get someone who perhaps has suffered a serious sexual assault to put themselves in the shoes of a perpetrator; however when they’ve witnessed a crime as an eyewitness rather than as a victim themselves then that is a very useful technique to get them to think about the bigger picture. It really helps people to think outside the box, and in lots of scenarios in life people have to think outside the box, and this is a way of doing it, getting people, instead of thinking about their role in an event, think about the role of other people, and that’s another way to trigger memory.

Those four techniques form the original cognitive interview, which were originally back in the early Eighties given to police officers to use as and when they wished within their normal interviewing. However research examining how police typically interview in the field was quite shocked that the police did not conform to what we would say is good appropriate interviewing to get maximum quantity and quality of information from people. We know through research the best way to interview someone is to start with what we say an open question, tell me everything, we get a free recall for someone, and what that means is someone can recall in a free manner, recall in any way they want. And they basically recall as much as they want and they have their own time. When that free recall has finished then what we do is we break that free recall up and we ask questions about topic areas in the order the person has remembered it, again using open questions.

It seems to go against common sense but to get information you do not need to ask lots and lots of questions, because every time you ask a question you are stopping that interviewee speaking, so really what you’re trying to do is basically get information from someone without asking as many questions, well, hold on, what you’ve got to do is get information from someone with asking the fewest questions possible. What we often say is the thing, the interview that a police officer is striving to achieve is the questionless interview, because every time a police officer asks a question there is the possibility of contamination of human memory, and so what we’re striving for when we’re training and teaching police officers is almost to try and get as much information as possible without contaminating memory, and so therefore that sort of golden ball in the sky that they are trying to achieve is the questionless interview. It doesn’t exist, it would be almost impossible to have a questionless interview; however if that’s what they’re looking for every time a police officer asks a question, they’re really trying to concentrate off what is the value of that question.

Because in everyday communication we ask hundreds of questions, we ask questions that we don’t really want the answer to, are you okay? You know really when we normally in everyday communication ask the question are you okay, we don’t want people to go actually not, I’m not okay and go into their ailments, we really just want out of courtesy yes, we’re fine. And so in normal conversation we ask questions which are very leading, married, family, children, we ask questions which we don’t want the answer to, we overtalk people, and so we can’t rely on our normal communication skills in a police interview because it’s not information gathering communication normally talking to people in a perhaps, you know, over dinner or in a pub scenario, and so we have to almost go against some of our normal conversational rules.

One of our conversational rules is something called the maxim of quantity. We learn from a very young age that speaking in lots of detail is very rude. And so, for example, I have a five year old son, and at the moment we’re teaching him turn taking. It’s mummy and daddy’s turn at the moment to speak, it’s your turn next. And so we learn from a very young age that giving lots of detail is not needed in normal conversation. However in a police interview that’s what we’re asking witnesses to do, give us detail. So if I’m asking a forty year old who has learned from the age of three that detail’s not required, we’re getting people to break normal conversational rules. We’re also getting the interviewers to break normal conversational rules.

So what we’ve found in what we call the typical standard police interview is that police officers tended, because they had no training prior to 1992 in Britain, they had no training how to do this very complex psychological task to interview to gather information. They were relying on their normal conversational skills, and those normal conversational skills aren’t information gathering approaches. So we suddenly realised as psychologists that we had to start training police officers not just to use techniques to enhance memory but we had to teach them techniques which basically got good communication skills for information gathering approaches.